TPress
1.
Manz, Sabina; Seifert, Dirk; Altenburg, Bjoern; Schmalz, Thomas; Dosen, Strahinja; Gonzalez-Vargas, Jose
In: Clinical Biomechanics, Bd. 106, S. 105988, 2023, ISSN: 0268-0033.
Abstract | Links | Schlagwörter: above knee prosthesis, adult, article, C-leg, Challenger, clinical article, controlled study, data analysis software, degree of freedom, endoprosthesis, feasibility study, foot prosthesis, gait, gait analysis system, gait deviation index, Genium X3, Germany, gold standard, human, kinematics, kinetics, knee angle, knee function, knee prosthesis, leg amputation, male, microprocessor, middle aged, motion analysis system, motion sensor, SPSS, strain gauge transducer, Taleo, thigh, Triton, tyloxapol, walk test, walking speed
@article{Manz2023,
title = {Using embedded prosthesis sensors for clinical gait analyses in people with lower limb amputation: A feasibility study},
author = {Sabina Manz and Dirk Seifert and Bjoern Altenburg and Thomas Schmalz and Strahinja Dosen and Jose Gonzalez-Vargas},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2024655048&from=export},
doi = {10.1016/j.clinbiomech.2023.105988},
issn = {0268-0033},
year = {2023},
date = {2023-06-01},
journal = {Clinical Biomechanics},
volume = {106},
pages = {105988},
publisher = {Elsevier BV},
address = {J. Gonzalez-Vargas, Ottobock SE & Co. KGaA, Duderstadt, Germany},
abstract = {Background: Biomechanical gait analyses are typically performed in laboratory settings, and are associated with limitations due to space, marker placement, and tasks that are not representative of the real-world usage of lower limb prostheses. Therefore, the purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee joint. Methods: Ten participants were recruited for this study and equipped with a Genium X3 prosthetic knee joint. They performed level walking, stair/ramp descent, and ascent. During these tasks, kinematics and kinetics (sagittal knee and thigh segment angle, and knee moment) were recorded using an optical motion capture system and force plates (gold standard), as well as the prosthesis-embedded sensors. Root mean square errors, relative errors, correlation coefficients, and discrete outcome variables of clinical relevance were calculated and compared between the gold standard and the embedded sensors. Findings: The average root mean square errors were found to be 0.6°, 5.3°, and 0.08 Nm/kg, for the knee angle, thigh angle, and knee moment, respectively. The average relative errors were 0.75% for the knee angle, 11.67% for the thigh angle, and 9.66%, for the knee moment. The discrete outcome variables showed small but significant differences between the two measurement systems for a number of tasks (higher differences only at the thigh). Interpretation: The findings highlight the potential of prosthesis-embedded sensors to accurately measure gait parameters across a wide range of tasks. This paves the way for assessing prosthesis performance in realistic environments outside the lab.},
keywords = {above knee prosthesis, adult, article, C-leg, Challenger, clinical article, controlled study, data analysis software, degree of freedom, endoprosthesis, feasibility study, foot prosthesis, gait, gait analysis system, gait deviation index, Genium X3, Germany, gold standard, human, kinematics, kinetics, knee angle, knee function, knee prosthesis, leg amputation, male, microprocessor, middle aged, motion analysis system, motion sensor, SPSS, strain gauge transducer, Taleo, thigh, Triton, tyloxapol, walk test, walking speed},
pubstate = {published},
tppubtype = {article}
}
Background: Biomechanical gait analyses are typically performed in laboratory settings, and are associated with limitations due to space, marker placement, and tasks that are not representative of the real-world usage of lower limb prostheses. Therefore, the purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee joint. Methods: Ten participants were recruited for this study and equipped with a Genium X3 prosthetic knee joint. They performed level walking, stair/ramp descent, and ascent. During these tasks, kinematics and kinetics (sagittal knee and thigh segment angle, and knee moment) were recorded using an optical motion capture system and force plates (gold standard), as well as the prosthesis-embedded sensors. Root mean square errors, relative errors, correlation coefficients, and discrete outcome variables of clinical relevance were calculated and compared between the gold standard and the embedded sensors. Findings: The average root mean square errors were found to be 0.6°, 5.3°, and 0.08 Nm/kg, for the knee angle, thigh angle, and knee moment, respectively. The average relative errors were 0.75% for the knee angle, 11.67% for the thigh angle, and 9.66%, for the knee moment. The discrete outcome variables showed small but significant differences between the two measurement systems for a number of tasks (higher differences only at the thigh). Interpretation: The findings highlight the potential of prosthesis-embedded sensors to accurately measure gait parameters across a wide range of tasks. This paves the way for assessing prosthesis performance in realistic environments outside the lab.
2.
Darter, B. J.; Syrett, E. D.; Foreman, K. B.; Kubiak, E.; Sinclair, S.
In: PLoS ONE, Bd. 18, Nr. 2 February, 2023, ISSN: 1932-6203.
Abstract | Links | Schlagwörter: adult, amputation, article, Axtion, biomechanics, bone plate, cane, clinical article, frontal plane, gait, hip, hip adduction angle, hip angle, human, kinematics, limb prosthesis, male, middle aged, motion analysis system, Ossur Rheo, Ottobock C-Leg, Ottobock Genium, Ottobock X3, pelvic angle, pelvis lab angle, Pro-Flex Pivo, prosthesis implantation, radiographic parameter, Renegade XL, Rush Low Profile, Rush Renegade, software agent, torque, Triton, Triton Low Profile, trunk, trunk flexion angle, trunk lab angle, trunk pelvis angle, tyloxapol, unilateral transfemoral amputation, walker, walking speed, Wave Sport
@article{Darter2023,
title = {Changes in frontal plane kinematics over 12-months in individuals with the Percutaneous Osseointegrated Prosthesis (POP)},
author = {B. J. Darter and E. D. Syrett and K. B. Foreman and E. Kubiak and S. Sinclair},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2023020092&from=export},
doi = {10.1371/journal.pone.0281339},
issn = {1932-6203},
year = {2023},
date = {2023-01-01},
journal = {PLoS ONE},
volume = {18},
number = {2 February},
address = {B.J. Darter, Department of Physical Therapy, Virginia Commonwealth University, Richmond, VA, United States},
abstract = {Background A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. Objective Examine changes in frontal plane movement patterns after BAP implantation. Methods Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12- months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. Results Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. Conclusions Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while withinparticipant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.},
keywords = {adult, amputation, article, Axtion, biomechanics, bone plate, cane, clinical article, frontal plane, gait, hip, hip adduction angle, hip angle, human, kinematics, limb prosthesis, male, middle aged, motion analysis system, Ossur Rheo, Ottobock C-Leg, Ottobock Genium, Ottobock X3, pelvic angle, pelvis lab angle, Pro-Flex Pivo, prosthesis implantation, radiographic parameter, Renegade XL, Rush Low Profile, Rush Renegade, software agent, torque, Triton, Triton Low Profile, trunk, trunk flexion angle, trunk lab angle, trunk pelvis angle, tyloxapol, unilateral transfemoral amputation, walker, walking speed, Wave Sport},
pubstate = {published},
tppubtype = {article}
}
Background A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. Objective Examine changes in frontal plane movement patterns after BAP implantation. Methods Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12- months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. Results Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. Conclusions Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while withinparticipant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.
3.
Ernst, M.; Altenburg, B.; Schmalz, T.; Kannenberg, A.; Bellmann, M.
Benefits of a microprocessor-controlled prosthetic foot for ascending and descending slopes Artikel
In: J. NeuroEng. Rehabil., Bd. 19, Nr. 1, 2022, ISSN: 1743-0003.
Abstract | Links | Schlagwörter: adult, aged, article, biomechanics, clinical article, controlled study, effect size, foot prosthesis, human, kinematics, knee function, leg amputation, microprocessor, middle aged, motion analysis system, patient participation, range of motion, slope factor, transfemoral amputation, transtibial amputation, walking
@article{Ernst2022,
title = {Benefits of a microprocessor-controlled prosthetic foot for ascending and descending slopes},
author = {M. Ernst and B. Altenburg and T. Schmalz and A. Kannenberg and M. Bellmann},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2014862458&from=export},
doi = {10.1186/s12984-022-00983-y},
issn = {1743-0003},
year = {2022},
date = {2022-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {19},
number = {1},
address = {M. Ernst, Research Biomechanics, CR&S, Ottobock SE & Co. KGaA, Göttingen, Germany},
abstract = {Background: Prosthetic feet are prescribed for persons with a lower-limb amputation to restore lost mobility. However, due to limited adaptability of their ankles and springs, situations like walking on slopes or uneven ground remain challenging. This study investigated to what extent a microprocessor-controlled prosthetic foot (MPF) facilitates walking on slopes. Methods: Seven persons each with a unilateral transtibial amputation (TTA) and unilateral transfemoral amputation (TFA) as well as ten able-bodied subjects participated. Participants were studied while using a MPF and their prescribed standard feet with fixed ankle attachments. The study investigated ascending and descending a 10° slope. Kinematic and kinetic data were recorded with a motion capture system. Biomechanical parameters, in particular leg joint angles, shank orientation and external joint moments of the prosthetics side were calculated. Results: Prosthetic feet- and subject group-dependent joint angle and moment characteristics were observed for both situations. The MPF showed a larger and situation-dependent ankle range of motion compared to the standard feet. Furthermore, it remained in a dorsiflexed position during swing. While ascending, the MPF adapted the dorsiflexion moment and reduced the knee extension moment. At vertical shank orientation, it reduced the knee extension moment by 26% for TFA and 49% for TTA compared to the standard feet. For descending, differences between feet in the biomechanical knee characteristics were found for the TTA group, but not for the TFA group. At the vertical shank angle during slope descent, TTA demonstrated a behavior of the ankle moment similar to able-bodied controls when using the MPF. Conclusions: The studied MPF facilitated walking on slopes by adapting instantaneously to inclinations and, thus, easing the forward rotation of the leg over the prosthetic foot compared to standard feet with a fixed ankle attachment with amputation-level dependent effect sizes. It assumed a dorsiflexed ankle angle during swing, enabled a larger ankle range of motion and reduced the moments acting on the residual knee of TTA compared to the prescribed prosthetic standard feet. For individuals with TFA, the prosthetic knee joint seems to play a more crucial role for walking on ramps than the foot.},
keywords = {adult, aged, article, biomechanics, clinical article, controlled study, effect size, foot prosthesis, human, kinematics, knee function, leg amputation, microprocessor, middle aged, motion analysis system, patient participation, range of motion, slope factor, transfemoral amputation, transtibial amputation, walking},
pubstate = {published},
tppubtype = {article}
}
Background: Prosthetic feet are prescribed for persons with a lower-limb amputation to restore lost mobility. However, due to limited adaptability of their ankles and springs, situations like walking on slopes or uneven ground remain challenging. This study investigated to what extent a microprocessor-controlled prosthetic foot (MPF) facilitates walking on slopes. Methods: Seven persons each with a unilateral transtibial amputation (TTA) and unilateral transfemoral amputation (TFA) as well as ten able-bodied subjects participated. Participants were studied while using a MPF and their prescribed standard feet with fixed ankle attachments. The study investigated ascending and descending a 10° slope. Kinematic and kinetic data were recorded with a motion capture system. Biomechanical parameters, in particular leg joint angles, shank orientation and external joint moments of the prosthetics side were calculated. Results: Prosthetic feet- and subject group-dependent joint angle and moment characteristics were observed for both situations. The MPF showed a larger and situation-dependent ankle range of motion compared to the standard feet. Furthermore, it remained in a dorsiflexed position during swing. While ascending, the MPF adapted the dorsiflexion moment and reduced the knee extension moment. At vertical shank orientation, it reduced the knee extension moment by 26% for TFA and 49% for TTA compared to the standard feet. For descending, differences between feet in the biomechanical knee characteristics were found for the TTA group, but not for the TFA group. At the vertical shank angle during slope descent, TTA demonstrated a behavior of the ankle moment similar to able-bodied controls when using the MPF. Conclusions: The studied MPF facilitated walking on slopes by adapting instantaneously to inclinations and, thus, easing the forward rotation of the leg over the prosthetic foot compared to standard feet with a fixed ankle attachment with amputation-level dependent effect sizes. It assumed a dorsiflexed ankle angle during swing, enabled a larger ankle range of motion and reduced the moments acting on the residual knee of TTA compared to the prescribed prosthetic standard feet. For individuals with TFA, the prosthetic knee joint seems to play a more crucial role for walking on ramps than the foot.
4.
Köhler, T. M.; Blumentritt, S.; Braatz, F.; Bellmann, M.
In: Gait Posture, Bd. 89, S. 169–177, 2021, ISSN: 0966-6362.
Abstract | Links | Schlagwörter: above knee amputation, adduction, adult, article, biomechanics, camera, clinical article, controlled study, female, femoral knee prosthesis, gait, Genium, ground reaction force, human, male, microprocessor, motion analysis system, pelvis, prosthetic alignment, step length, transfemoral amputation, transfemoral prosthetic socket, Triton, trunk, tyloxapol, Vicon Bonita, walking, walking speed
@article{Koehler2021,
title = {The impact of transfemoral socket adduction on pelvic and trunk stabilization during level walking - A biomechanical study},
author = {T. M. Köhler and S. Blumentritt and F. Braatz and M. Bellmann},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2013710687&from=export},
doi = {10.1016/j.gaitpost.2021.06.024},
issn = {0966-6362},
year = {2021},
date = {2021-09-01},
journal = {Gait Posture},
volume = {89},
pages = {169–177},
publisher = {Elsevier BV},
address = {T.M. Köhler, Ottobock SE & Co. KGaA, Hermann-Rein-Straße 2a, Göttingen, Germany},
abstract = {Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. Research question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.},
keywords = {above knee amputation, adduction, adult, article, biomechanics, camera, clinical article, controlled study, female, femoral knee prosthesis, gait, Genium, ground reaction force, human, male, microprocessor, motion analysis system, pelvis, prosthetic alignment, step length, transfemoral amputation, transfemoral prosthetic socket, Triton, trunk, tyloxapol, Vicon Bonita, walking, walking speed},
pubstate = {published},
tppubtype = {article}
}
Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. Research question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.
5.
Yazdani, M.; Hajiaghaei, B.; Saeedi, H.; Kamali, M.; Yousefi, M.
In: Curr. Orthop. Pract., Bd. 32, Nr. 5, S. 505–511, 2021, ISSN: 1940-7041.
Abstract | Links | Schlagwörter: adult, amputee, article, camera, case study, clinical article, comparative study, compression release stabilization, data analysis software, evaluation study, female, femoral shaft, foot prosthesis, gait, gluteus muscle, human, information processing device, IRCT20181021041400N1, ischial tuberosity, kinematics, knee prosthesis, leather belt wrap, limb amputation, male, MATLAB, medical device, middle aged, motion analysis system, orthopedic cast, orthopedic surgical equipment, Ottobock 3R20, pilot study, prosthesis design, quadrilateral socket, solid ankle cushioned heel foot, statistical model, step length, step time, step width, stride length, stride time, symmetry index, transfemoral socket, walking, walking speed, weight training, Wilcoxon signed ranks test
@article{Yazdani2021,
title = {Does the socket design affect symmetry and spatiotemporal gait parameters? A case series of two transfemoral amputees},
author = {M. Yazdani and B. Hajiaghaei and H. Saeedi and M. Kamali and M. Yousefi},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L635549609&from=export},
doi = {10.1097/bco.0000000000001022},
issn = {1940-7041},
year = {2021},
date = {2021-01-01},
journal = {Curr. Orthop. Pract.},
volume = {32},
number = {5},
pages = {505–511},
address = {B. Hajiaghaei, Department of Orthotics and Prosthetics, School of Rehabilitation Sciences, Iran University of Medical Sciences, Nezam Ave, Tehran, Iran},
abstract = {Background: Socket design is thought to improve gait performance and symmetry as the other components of the prosthesis do. This study focused on the comparison of two different sockets in transfemoral amputee patients to evaluate the influence of the socket designs on gait symmetry and various spatiotemporal gait parameters. Methods: Two transfemoral amputees participated in this case series study. They were asked to walk with the quadrilateral and the new modified sockets along a 10-meter walkway. The marker-based motion capture system recorded the spatiotemporal gait data during all walking trials. Kinematic data were compared between the two test conditions using the Wilcoxon signed-rank test and Symmetry Index. Results: The new socket increased velocity and cadence and reduced step width in both amputees, compared with the quadrilateral sockets. However, a good symmetry was observed in step length, stride length, step time, and stride time within two limbs by both sockets (SI ≤10). Conclusions: The design of sockets in this study had no observed effect on gait symmetry; however, the new socket increased velocity and cadence and reduced width step in both patients compared with the quadrilateral socket. Level of Evidence: Level IV.},
keywords = {adult, amputee, article, camera, case study, clinical article, comparative study, compression release stabilization, data analysis software, evaluation study, female, femoral shaft, foot prosthesis, gait, gluteus muscle, human, information processing device, IRCT20181021041400N1, ischial tuberosity, kinematics, knee prosthesis, leather belt wrap, limb amputation, male, MATLAB, medical device, middle aged, motion analysis system, orthopedic cast, orthopedic surgical equipment, Ottobock 3R20, pilot study, prosthesis design, quadrilateral socket, solid ankle cushioned heel foot, statistical model, step length, step time, step width, stride length, stride time, symmetry index, transfemoral socket, walking, walking speed, weight training, Wilcoxon signed ranks test},
pubstate = {published},
tppubtype = {article}
}
Background: Socket design is thought to improve gait performance and symmetry as the other components of the prosthesis do. This study focused on the comparison of two different sockets in transfemoral amputee patients to evaluate the influence of the socket designs on gait symmetry and various spatiotemporal gait parameters. Methods: Two transfemoral amputees participated in this case series study. They were asked to walk with the quadrilateral and the new modified sockets along a 10-meter walkway. The marker-based motion capture system recorded the spatiotemporal gait data during all walking trials. Kinematic data were compared between the two test conditions using the Wilcoxon signed-rank test and Symmetry Index. Results: The new socket increased velocity and cadence and reduced step width in both amputees, compared with the quadrilateral sockets. However, a good symmetry was observed in step length, stride length, step time, and stride time within two limbs by both sockets (SI ≤10). Conclusions: The design of sockets in this study had no observed effect on gait symmetry; however, the new socket increased velocity and cadence and reduced width step in both patients compared with the quadrilateral socket. Level of Evidence: Level IV.
2023
Manz, Sabina; Seifert, Dirk; Altenburg, Bjoern; Schmalz, Thomas; Dosen, Strahinja; Gonzalez-Vargas, Jose
In: Clinical Biomechanics, Bd. 106, S. 105988, 2023, ISSN: 0268-0033.
Abstract | Links | Schlagwörter: above knee prosthesis, adult, article, C-leg, Challenger, clinical article, controlled study, data analysis software, degree of freedom, endoprosthesis, feasibility study, foot prosthesis, gait, gait analysis system, gait deviation index, Genium X3, Germany, gold standard, human, kinematics, kinetics, knee angle, knee function, knee prosthesis, leg amputation, male, microprocessor, middle aged, motion analysis system, motion sensor, SPSS, strain gauge transducer, Taleo, thigh, Triton, tyloxapol, walk test, walking speed
@article{Manz2023,
title = {Using embedded prosthesis sensors for clinical gait analyses in people with lower limb amputation: A feasibility study},
author = {Sabina Manz and Dirk Seifert and Bjoern Altenburg and Thomas Schmalz and Strahinja Dosen and Jose Gonzalez-Vargas},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2024655048&from=export},
doi = {10.1016/j.clinbiomech.2023.105988},
issn = {0268-0033},
year = {2023},
date = {2023-06-01},
journal = {Clinical Biomechanics},
volume = {106},
pages = {105988},
publisher = {Elsevier BV},
address = {J. Gonzalez-Vargas, Ottobock SE & Co. KGaA, Duderstadt, Germany},
abstract = {Background: Biomechanical gait analyses are typically performed in laboratory settings, and are associated with limitations due to space, marker placement, and tasks that are not representative of the real-world usage of lower limb prostheses. Therefore, the purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee joint. Methods: Ten participants were recruited for this study and equipped with a Genium X3 prosthetic knee joint. They performed level walking, stair/ramp descent, and ascent. During these tasks, kinematics and kinetics (sagittal knee and thigh segment angle, and knee moment) were recorded using an optical motion capture system and force plates (gold standard), as well as the prosthesis-embedded sensors. Root mean square errors, relative errors, correlation coefficients, and discrete outcome variables of clinical relevance were calculated and compared between the gold standard and the embedded sensors. Findings: The average root mean square errors were found to be 0.6°, 5.3°, and 0.08 Nm/kg, for the knee angle, thigh angle, and knee moment, respectively. The average relative errors were 0.75% for the knee angle, 11.67% for the thigh angle, and 9.66%, for the knee moment. The discrete outcome variables showed small but significant differences between the two measurement systems for a number of tasks (higher differences only at the thigh). Interpretation: The findings highlight the potential of prosthesis-embedded sensors to accurately measure gait parameters across a wide range of tasks. This paves the way for assessing prosthesis performance in realistic environments outside the lab.},
keywords = {above knee prosthesis, adult, article, C-leg, Challenger, clinical article, controlled study, data analysis software, degree of freedom, endoprosthesis, feasibility study, foot prosthesis, gait, gait analysis system, gait deviation index, Genium X3, Germany, gold standard, human, kinematics, kinetics, knee angle, knee function, knee prosthesis, leg amputation, male, microprocessor, middle aged, motion analysis system, motion sensor, SPSS, strain gauge transducer, Taleo, thigh, Triton, tyloxapol, walk test, walking speed},
pubstate = {published},
tppubtype = {article}
}
Background: Biomechanical gait analyses are typically performed in laboratory settings, and are associated with limitations due to space, marker placement, and tasks that are not representative of the real-world usage of lower limb prostheses. Therefore, the purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee joint. Methods: Ten participants were recruited for this study and equipped with a Genium X3 prosthetic knee joint. They performed level walking, stair/ramp descent, and ascent. During these tasks, kinematics and kinetics (sagittal knee and thigh segment angle, and knee moment) were recorded using an optical motion capture system and force plates (gold standard), as well as the prosthesis-embedded sensors. Root mean square errors, relative errors, correlation coefficients, and discrete outcome variables of clinical relevance were calculated and compared between the gold standard and the embedded sensors. Findings: The average root mean square errors were found to be 0.6°, 5.3°, and 0.08 Nm/kg, for the knee angle, thigh angle, and knee moment, respectively. The average relative errors were 0.75% for the knee angle, 11.67% for the thigh angle, and 9.66%, for the knee moment. The discrete outcome variables showed small but significant differences between the two measurement systems for a number of tasks (higher differences only at the thigh). Interpretation: The findings highlight the potential of prosthesis-embedded sensors to accurately measure gait parameters across a wide range of tasks. This paves the way for assessing prosthesis performance in realistic environments outside the lab.
Darter, B. J.; Syrett, E. D.; Foreman, K. B.; Kubiak, E.; Sinclair, S.
In: PLoS ONE, Bd. 18, Nr. 2 February, 2023, ISSN: 1932-6203.
Abstract | Links | Schlagwörter: adult, amputation, article, Axtion, biomechanics, bone plate, cane, clinical article, frontal plane, gait, hip, hip adduction angle, hip angle, human, kinematics, limb prosthesis, male, middle aged, motion analysis system, Ossur Rheo, Ottobock C-Leg, Ottobock Genium, Ottobock X3, pelvic angle, pelvis lab angle, Pro-Flex Pivo, prosthesis implantation, radiographic parameter, Renegade XL, Rush Low Profile, Rush Renegade, software agent, torque, Triton, Triton Low Profile, trunk, trunk flexion angle, trunk lab angle, trunk pelvis angle, tyloxapol, unilateral transfemoral amputation, walker, walking speed, Wave Sport
@article{Darter2023,
title = {Changes in frontal plane kinematics over 12-months in individuals with the Percutaneous Osseointegrated Prosthesis (POP)},
author = {B. J. Darter and E. D. Syrett and K. B. Foreman and E. Kubiak and S. Sinclair},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2023020092&from=export},
doi = {10.1371/journal.pone.0281339},
issn = {1932-6203},
year = {2023},
date = {2023-01-01},
journal = {PLoS ONE},
volume = {18},
number = {2 February},
address = {B.J. Darter, Department of Physical Therapy, Virginia Commonwealth University, Richmond, VA, United States},
abstract = {Background A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. Objective Examine changes in frontal plane movement patterns after BAP implantation. Methods Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12- months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. Results Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. Conclusions Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while withinparticipant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.},
keywords = {adult, amputation, article, Axtion, biomechanics, bone plate, cane, clinical article, frontal plane, gait, hip, hip adduction angle, hip angle, human, kinematics, limb prosthesis, male, middle aged, motion analysis system, Ossur Rheo, Ottobock C-Leg, Ottobock Genium, Ottobock X3, pelvic angle, pelvis lab angle, Pro-Flex Pivo, prosthesis implantation, radiographic parameter, Renegade XL, Rush Low Profile, Rush Renegade, software agent, torque, Triton, Triton Low Profile, trunk, trunk flexion angle, trunk lab angle, trunk pelvis angle, tyloxapol, unilateral transfemoral amputation, walker, walking speed, Wave Sport},
pubstate = {published},
tppubtype = {article}
}
Background A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. Objective Examine changes in frontal plane movement patterns after BAP implantation. Methods Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12- months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. Results Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. Conclusions Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while withinparticipant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.
2022
Ernst, M.; Altenburg, B.; Schmalz, T.; Kannenberg, A.; Bellmann, M.
Benefits of a microprocessor-controlled prosthetic foot for ascending and descending slopes Artikel
In: J. NeuroEng. Rehabil., Bd. 19, Nr. 1, 2022, ISSN: 1743-0003.
Abstract | Links | Schlagwörter: adult, aged, article, biomechanics, clinical article, controlled study, effect size, foot prosthesis, human, kinematics, knee function, leg amputation, microprocessor, middle aged, motion analysis system, patient participation, range of motion, slope factor, transfemoral amputation, transtibial amputation, walking
@article{Ernst2022,
title = {Benefits of a microprocessor-controlled prosthetic foot for ascending and descending slopes},
author = {M. Ernst and B. Altenburg and T. Schmalz and A. Kannenberg and M. Bellmann},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2014862458&from=export},
doi = {10.1186/s12984-022-00983-y},
issn = {1743-0003},
year = {2022},
date = {2022-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {19},
number = {1},
address = {M. Ernst, Research Biomechanics, CR&S, Ottobock SE & Co. KGaA, Göttingen, Germany},
abstract = {Background: Prosthetic feet are prescribed for persons with a lower-limb amputation to restore lost mobility. However, due to limited adaptability of their ankles and springs, situations like walking on slopes or uneven ground remain challenging. This study investigated to what extent a microprocessor-controlled prosthetic foot (MPF) facilitates walking on slopes. Methods: Seven persons each with a unilateral transtibial amputation (TTA) and unilateral transfemoral amputation (TFA) as well as ten able-bodied subjects participated. Participants were studied while using a MPF and their prescribed standard feet with fixed ankle attachments. The study investigated ascending and descending a 10° slope. Kinematic and kinetic data were recorded with a motion capture system. Biomechanical parameters, in particular leg joint angles, shank orientation and external joint moments of the prosthetics side were calculated. Results: Prosthetic feet- and subject group-dependent joint angle and moment characteristics were observed for both situations. The MPF showed a larger and situation-dependent ankle range of motion compared to the standard feet. Furthermore, it remained in a dorsiflexed position during swing. While ascending, the MPF adapted the dorsiflexion moment and reduced the knee extension moment. At vertical shank orientation, it reduced the knee extension moment by 26% for TFA and 49% for TTA compared to the standard feet. For descending, differences between feet in the biomechanical knee characteristics were found for the TTA group, but not for the TFA group. At the vertical shank angle during slope descent, TTA demonstrated a behavior of the ankle moment similar to able-bodied controls when using the MPF. Conclusions: The studied MPF facilitated walking on slopes by adapting instantaneously to inclinations and, thus, easing the forward rotation of the leg over the prosthetic foot compared to standard feet with a fixed ankle attachment with amputation-level dependent effect sizes. It assumed a dorsiflexed ankle angle during swing, enabled a larger ankle range of motion and reduced the moments acting on the residual knee of TTA compared to the prescribed prosthetic standard feet. For individuals with TFA, the prosthetic knee joint seems to play a more crucial role for walking on ramps than the foot.},
keywords = {adult, aged, article, biomechanics, clinical article, controlled study, effect size, foot prosthesis, human, kinematics, knee function, leg amputation, microprocessor, middle aged, motion analysis system, patient participation, range of motion, slope factor, transfemoral amputation, transtibial amputation, walking},
pubstate = {published},
tppubtype = {article}
}
Background: Prosthetic feet are prescribed for persons with a lower-limb amputation to restore lost mobility. However, due to limited adaptability of their ankles and springs, situations like walking on slopes or uneven ground remain challenging. This study investigated to what extent a microprocessor-controlled prosthetic foot (MPF) facilitates walking on slopes. Methods: Seven persons each with a unilateral transtibial amputation (TTA) and unilateral transfemoral amputation (TFA) as well as ten able-bodied subjects participated. Participants were studied while using a MPF and their prescribed standard feet with fixed ankle attachments. The study investigated ascending and descending a 10° slope. Kinematic and kinetic data were recorded with a motion capture system. Biomechanical parameters, in particular leg joint angles, shank orientation and external joint moments of the prosthetics side were calculated. Results: Prosthetic feet- and subject group-dependent joint angle and moment characteristics were observed for both situations. The MPF showed a larger and situation-dependent ankle range of motion compared to the standard feet. Furthermore, it remained in a dorsiflexed position during swing. While ascending, the MPF adapted the dorsiflexion moment and reduced the knee extension moment. At vertical shank orientation, it reduced the knee extension moment by 26% for TFA and 49% for TTA compared to the standard feet. For descending, differences between feet in the biomechanical knee characteristics were found for the TTA group, but not for the TFA group. At the vertical shank angle during slope descent, TTA demonstrated a behavior of the ankle moment similar to able-bodied controls when using the MPF. Conclusions: The studied MPF facilitated walking on slopes by adapting instantaneously to inclinations and, thus, easing the forward rotation of the leg over the prosthetic foot compared to standard feet with a fixed ankle attachment with amputation-level dependent effect sizes. It assumed a dorsiflexed ankle angle during swing, enabled a larger ankle range of motion and reduced the moments acting on the residual knee of TTA compared to the prescribed prosthetic standard feet. For individuals with TFA, the prosthetic knee joint seems to play a more crucial role for walking on ramps than the foot.
2021
Köhler, T. M.; Blumentritt, S.; Braatz, F.; Bellmann, M.
In: Gait Posture, Bd. 89, S. 169–177, 2021, ISSN: 0966-6362.
Abstract | Links | Schlagwörter: above knee amputation, adduction, adult, article, biomechanics, camera, clinical article, controlled study, female, femoral knee prosthesis, gait, Genium, ground reaction force, human, male, microprocessor, motion analysis system, pelvis, prosthetic alignment, step length, transfemoral amputation, transfemoral prosthetic socket, Triton, trunk, tyloxapol, Vicon Bonita, walking, walking speed
@article{Koehler2021,
title = {The impact of transfemoral socket adduction on pelvic and trunk stabilization during level walking - A biomechanical study},
author = {T. M. Köhler and S. Blumentritt and F. Braatz and M. Bellmann},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2013710687&from=export},
doi = {10.1016/j.gaitpost.2021.06.024},
issn = {0966-6362},
year = {2021},
date = {2021-09-01},
journal = {Gait Posture},
volume = {89},
pages = {169–177},
publisher = {Elsevier BV},
address = {T.M. Köhler, Ottobock SE & Co. KGaA, Hermann-Rein-Straße 2a, Göttingen, Germany},
abstract = {Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. Research question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.},
keywords = {above knee amputation, adduction, adult, article, biomechanics, camera, clinical article, controlled study, female, femoral knee prosthesis, gait, Genium, ground reaction force, human, male, microprocessor, motion analysis system, pelvis, prosthetic alignment, step length, transfemoral amputation, transfemoral prosthetic socket, Triton, trunk, tyloxapol, Vicon Bonita, walking, walking speed},
pubstate = {published},
tppubtype = {article}
}
Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. Research question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.
Yazdani, M.; Hajiaghaei, B.; Saeedi, H.; Kamali, M.; Yousefi, M.
In: Curr. Orthop. Pract., Bd. 32, Nr. 5, S. 505–511, 2021, ISSN: 1940-7041.
Abstract | Links | Schlagwörter: adult, amputee, article, camera, case study, clinical article, comparative study, compression release stabilization, data analysis software, evaluation study, female, femoral shaft, foot prosthesis, gait, gluteus muscle, human, information processing device, IRCT20181021041400N1, ischial tuberosity, kinematics, knee prosthesis, leather belt wrap, limb amputation, male, MATLAB, medical device, middle aged, motion analysis system, orthopedic cast, orthopedic surgical equipment, Ottobock 3R20, pilot study, prosthesis design, quadrilateral socket, solid ankle cushioned heel foot, statistical model, step length, step time, step width, stride length, stride time, symmetry index, transfemoral socket, walking, walking speed, weight training, Wilcoxon signed ranks test
@article{Yazdani2021,
title = {Does the socket design affect symmetry and spatiotemporal gait parameters? A case series of two transfemoral amputees},
author = {M. Yazdani and B. Hajiaghaei and H. Saeedi and M. Kamali and M. Yousefi},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L635549609&from=export},
doi = {10.1097/bco.0000000000001022},
issn = {1940-7041},
year = {2021},
date = {2021-01-01},
journal = {Curr. Orthop. Pract.},
volume = {32},
number = {5},
pages = {505–511},
address = {B. Hajiaghaei, Department of Orthotics and Prosthetics, School of Rehabilitation Sciences, Iran University of Medical Sciences, Nezam Ave, Tehran, Iran},
abstract = {Background: Socket design is thought to improve gait performance and symmetry as the other components of the prosthesis do. This study focused on the comparison of two different sockets in transfemoral amputee patients to evaluate the influence of the socket designs on gait symmetry and various spatiotemporal gait parameters. Methods: Two transfemoral amputees participated in this case series study. They were asked to walk with the quadrilateral and the new modified sockets along a 10-meter walkway. The marker-based motion capture system recorded the spatiotemporal gait data during all walking trials. Kinematic data were compared between the two test conditions using the Wilcoxon signed-rank test and Symmetry Index. Results: The new socket increased velocity and cadence and reduced step width in both amputees, compared with the quadrilateral sockets. However, a good symmetry was observed in step length, stride length, step time, and stride time within two limbs by both sockets (SI ≤10). Conclusions: The design of sockets in this study had no observed effect on gait symmetry; however, the new socket increased velocity and cadence and reduced width step in both patients compared with the quadrilateral socket. Level of Evidence: Level IV.},
keywords = {adult, amputee, article, camera, case study, clinical article, comparative study, compression release stabilization, data analysis software, evaluation study, female, femoral shaft, foot prosthesis, gait, gluteus muscle, human, information processing device, IRCT20181021041400N1, ischial tuberosity, kinematics, knee prosthesis, leather belt wrap, limb amputation, male, MATLAB, medical device, middle aged, motion analysis system, orthopedic cast, orthopedic surgical equipment, Ottobock 3R20, pilot study, prosthesis design, quadrilateral socket, solid ankle cushioned heel foot, statistical model, step length, step time, step width, stride length, stride time, symmetry index, transfemoral socket, walking, walking speed, weight training, Wilcoxon signed ranks test},
pubstate = {published},
tppubtype = {article}
}
Background: Socket design is thought to improve gait performance and symmetry as the other components of the prosthesis do. This study focused on the comparison of two different sockets in transfemoral amputee patients to evaluate the influence of the socket designs on gait symmetry and various spatiotemporal gait parameters. Methods: Two transfemoral amputees participated in this case series study. They were asked to walk with the quadrilateral and the new modified sockets along a 10-meter walkway. The marker-based motion capture system recorded the spatiotemporal gait data during all walking trials. Kinematic data were compared between the two test conditions using the Wilcoxon signed-rank test and Symmetry Index. Results: The new socket increased velocity and cadence and reduced step width in both amputees, compared with the quadrilateral sockets. However, a good symmetry was observed in step length, stride length, step time, and stride time within two limbs by both sockets (SI ≤10). Conclusions: The design of sockets in this study had no observed effect on gait symmetry; however, the new socket increased velocity and cadence and reduced width step in both patients compared with the quadrilateral socket. Level of Evidence: Level IV.
2023
Manz, Sabina; Seifert, Dirk; Altenburg, Bjoern; Schmalz, Thomas; Dosen, Strahinja; Gonzalez-Vargas, Jose
In: Clinical Biomechanics, Bd. 106, S. 105988, 2023, ISSN: 0268-0033.
@article{Manz2023,
title = {Using embedded prosthesis sensors for clinical gait analyses in people with lower limb amputation: A feasibility study},
author = {Sabina Manz and Dirk Seifert and Bjoern Altenburg and Thomas Schmalz and Strahinja Dosen and Jose Gonzalez-Vargas},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2024655048&from=export},
doi = {10.1016/j.clinbiomech.2023.105988},
issn = {0268-0033},
year = {2023},
date = {2023-06-01},
journal = {Clinical Biomechanics},
volume = {106},
pages = {105988},
publisher = {Elsevier BV},
address = {J. Gonzalez-Vargas, Ottobock SE & Co. KGaA, Duderstadt, Germany},
abstract = {Background: Biomechanical gait analyses are typically performed in laboratory settings, and are associated with limitations due to space, marker placement, and tasks that are not representative of the real-world usage of lower limb prostheses. Therefore, the purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee joint. Methods: Ten participants were recruited for this study and equipped with a Genium X3 prosthetic knee joint. They performed level walking, stair/ramp descent, and ascent. During these tasks, kinematics and kinetics (sagittal knee and thigh segment angle, and knee moment) were recorded using an optical motion capture system and force plates (gold standard), as well as the prosthesis-embedded sensors. Root mean square errors, relative errors, correlation coefficients, and discrete outcome variables of clinical relevance were calculated and compared between the gold standard and the embedded sensors. Findings: The average root mean square errors were found to be 0.6°, 5.3°, and 0.08 Nm/kg, for the knee angle, thigh angle, and knee moment, respectively. The average relative errors were 0.75% for the knee angle, 11.67% for the thigh angle, and 9.66%, for the knee moment. The discrete outcome variables showed small but significant differences between the two measurement systems for a number of tasks (higher differences only at the thigh). Interpretation: The findings highlight the potential of prosthesis-embedded sensors to accurately measure gait parameters across a wide range of tasks. This paves the way for assessing prosthesis performance in realistic environments outside the lab.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Biomechanical gait analyses are typically performed in laboratory settings, and are associated with limitations due to space, marker placement, and tasks that are not representative of the real-world usage of lower limb prostheses. Therefore, the purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee joint. Methods: Ten participants were recruited for this study and equipped with a Genium X3 prosthetic knee joint. They performed level walking, stair/ramp descent, and ascent. During these tasks, kinematics and kinetics (sagittal knee and thigh segment angle, and knee moment) were recorded using an optical motion capture system and force plates (gold standard), as well as the prosthesis-embedded sensors. Root mean square errors, relative errors, correlation coefficients, and discrete outcome variables of clinical relevance were calculated and compared between the gold standard and the embedded sensors. Findings: The average root mean square errors were found to be 0.6°, 5.3°, and 0.08 Nm/kg, for the knee angle, thigh angle, and knee moment, respectively. The average relative errors were 0.75% for the knee angle, 11.67% for the thigh angle, and 9.66%, for the knee moment. The discrete outcome variables showed small but significant differences between the two measurement systems for a number of tasks (higher differences only at the thigh). Interpretation: The findings highlight the potential of prosthesis-embedded sensors to accurately measure gait parameters across a wide range of tasks. This paves the way for assessing prosthesis performance in realistic environments outside the lab.
Darter, B. J.; Syrett, E. D.; Foreman, K. B.; Kubiak, E.; Sinclair, S.
In: PLoS ONE, Bd. 18, Nr. 2 February, 2023, ISSN: 1932-6203.
@article{Darter2023,
title = {Changes in frontal plane kinematics over 12-months in individuals with the Percutaneous Osseointegrated Prosthesis (POP)},
author = {B. J. Darter and E. D. Syrett and K. B. Foreman and E. Kubiak and S. Sinclair},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2023020092&from=export},
doi = {10.1371/journal.pone.0281339},
issn = {1932-6203},
year = {2023},
date = {2023-01-01},
journal = {PLoS ONE},
volume = {18},
number = {2 February},
address = {B.J. Darter, Department of Physical Therapy, Virginia Commonwealth University, Richmond, VA, United States},
abstract = {Background A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. Objective Examine changes in frontal plane movement patterns after BAP implantation. Methods Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12- months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. Results Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. Conclusions Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while withinparticipant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background A bone-anchored prosthesis (BAP) eliminates the need for a conventional socket by attaching a prosthesis directly to the user's skeleton. Currently, limited research addresses changes in gait mechanics post BAP implantation. Objective Examine changes in frontal plane movement patterns after BAP implantation. Methods Participants were individuals with unilateral transfemoral amputation (TFA) enrolled in the US Food and Drug Administration (FDA) Early Feasibility Study examining the Percutaneous Osseointegrated Prosthesis (POP). The participants completed overground gait assessments using their conventional socket and at 6-weeks, 12-weeks, 6-months, and 12- months following POP implantation. Statistical parameter mapping techniques were used in examining changes in frontal plane kinematics over the 12-months and differences with reference values for individuals without limb loss. Results Statistically significant deviations were found pre-implantation compared to reference values for hip and trunk angles during prosthetic limb stance phase, and for pelvis and trunk relative to the pelvis angles during prosthetic limb swing. At 6-weeks post-implantation, only the trunk angle demonstrated a statistically significant reduction in the percent of gait cycle with deviations relative to reference values. At 12-months post-implantation, results revealed frontal plane movements were no longer statistically different across the gait cycle for the trunk angle compared to reference values, and less of the gait cycle was statistically different compared to reference values for all other frontal plane patterns analyzed. No statistically significant within-participant differences were found for frontal plane movement patterns between pre-implantation and 6-weeks or 12-months post-implantation. Conclusions Deviations from reference values displayed prior to device implantation were reduced or eliminated 12-months post-implantation in all frontal plane patterns analyzed, while withinparticipant changes over the 12-month period did not reach statistical significance. Overall, the results suggest the transition to a BAP aided in normalizing gait patterns in a sample of relatively high functioning individuals with TFA.
2022
Ernst, M.; Altenburg, B.; Schmalz, T.; Kannenberg, A.; Bellmann, M.
Benefits of a microprocessor-controlled prosthetic foot for ascending and descending slopes Artikel
In: J. NeuroEng. Rehabil., Bd. 19, Nr. 1, 2022, ISSN: 1743-0003.
@article{Ernst2022,
title = {Benefits of a microprocessor-controlled prosthetic foot for ascending and descending slopes},
author = {M. Ernst and B. Altenburg and T. Schmalz and A. Kannenberg and M. Bellmann},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2014862458&from=export},
doi = {10.1186/s12984-022-00983-y},
issn = {1743-0003},
year = {2022},
date = {2022-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {19},
number = {1},
address = {M. Ernst, Research Biomechanics, CR&S, Ottobock SE & Co. KGaA, Göttingen, Germany},
abstract = {Background: Prosthetic feet are prescribed for persons with a lower-limb amputation to restore lost mobility. However, due to limited adaptability of their ankles and springs, situations like walking on slopes or uneven ground remain challenging. This study investigated to what extent a microprocessor-controlled prosthetic foot (MPF) facilitates walking on slopes. Methods: Seven persons each with a unilateral transtibial amputation (TTA) and unilateral transfemoral amputation (TFA) as well as ten able-bodied subjects participated. Participants were studied while using a MPF and their prescribed standard feet with fixed ankle attachments. The study investigated ascending and descending a 10° slope. Kinematic and kinetic data were recorded with a motion capture system. Biomechanical parameters, in particular leg joint angles, shank orientation and external joint moments of the prosthetics side were calculated. Results: Prosthetic feet- and subject group-dependent joint angle and moment characteristics were observed for both situations. The MPF showed a larger and situation-dependent ankle range of motion compared to the standard feet. Furthermore, it remained in a dorsiflexed position during swing. While ascending, the MPF adapted the dorsiflexion moment and reduced the knee extension moment. At vertical shank orientation, it reduced the knee extension moment by 26% for TFA and 49% for TTA compared to the standard feet. For descending, differences between feet in the biomechanical knee characteristics were found for the TTA group, but not for the TFA group. At the vertical shank angle during slope descent, TTA demonstrated a behavior of the ankle moment similar to able-bodied controls when using the MPF. Conclusions: The studied MPF facilitated walking on slopes by adapting instantaneously to inclinations and, thus, easing the forward rotation of the leg over the prosthetic foot compared to standard feet with a fixed ankle attachment with amputation-level dependent effect sizes. It assumed a dorsiflexed ankle angle during swing, enabled a larger ankle range of motion and reduced the moments acting on the residual knee of TTA compared to the prescribed prosthetic standard feet. For individuals with TFA, the prosthetic knee joint seems to play a more crucial role for walking on ramps than the foot.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Prosthetic feet are prescribed for persons with a lower-limb amputation to restore lost mobility. However, due to limited adaptability of their ankles and springs, situations like walking on slopes or uneven ground remain challenging. This study investigated to what extent a microprocessor-controlled prosthetic foot (MPF) facilitates walking on slopes. Methods: Seven persons each with a unilateral transtibial amputation (TTA) and unilateral transfemoral amputation (TFA) as well as ten able-bodied subjects participated. Participants were studied while using a MPF and their prescribed standard feet with fixed ankle attachments. The study investigated ascending and descending a 10° slope. Kinematic and kinetic data were recorded with a motion capture system. Biomechanical parameters, in particular leg joint angles, shank orientation and external joint moments of the prosthetics side were calculated. Results: Prosthetic feet- and subject group-dependent joint angle and moment characteristics were observed for both situations. The MPF showed a larger and situation-dependent ankle range of motion compared to the standard feet. Furthermore, it remained in a dorsiflexed position during swing. While ascending, the MPF adapted the dorsiflexion moment and reduced the knee extension moment. At vertical shank orientation, it reduced the knee extension moment by 26% for TFA and 49% for TTA compared to the standard feet. For descending, differences between feet in the biomechanical knee characteristics were found for the TTA group, but not for the TFA group. At the vertical shank angle during slope descent, TTA demonstrated a behavior of the ankle moment similar to able-bodied controls when using the MPF. Conclusions: The studied MPF facilitated walking on slopes by adapting instantaneously to inclinations and, thus, easing the forward rotation of the leg over the prosthetic foot compared to standard feet with a fixed ankle attachment with amputation-level dependent effect sizes. It assumed a dorsiflexed ankle angle during swing, enabled a larger ankle range of motion and reduced the moments acting on the residual knee of TTA compared to the prescribed prosthetic standard feet. For individuals with TFA, the prosthetic knee joint seems to play a more crucial role for walking on ramps than the foot.
2021
Köhler, T. M.; Blumentritt, S.; Braatz, F.; Bellmann, M.
In: Gait Posture, Bd. 89, S. 169–177, 2021, ISSN: 0966-6362.
@article{Koehler2021,
title = {The impact of transfemoral socket adduction on pelvic and trunk stabilization during level walking - A biomechanical study},
author = {T. M. Köhler and S. Blumentritt and F. Braatz and M. Bellmann},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2013710687&from=export},
doi = {10.1016/j.gaitpost.2021.06.024},
issn = {0966-6362},
year = {2021},
date = {2021-09-01},
journal = {Gait Posture},
volume = {89},
pages = {169–177},
publisher = {Elsevier BV},
address = {T.M. Köhler, Ottobock SE & Co. KGaA, Hermann-Rein-Straße 2a, Göttingen, Germany},
abstract = {Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. Research question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: It is common practice to align transfemoral prosthetic sockets in adduction, due to the physiologic, adducted femoral alignment in unimpaired legs. An adducted femoral and socket alignment helps tightening hip abductors to stabilize the pelvis and reduce pelvic and trunk related compensatory movements. Research question: How do different socket adduction conditions (SAC) of transfemoral sockets affect pelvic and trunk stabilization during level ground walking in the frontal plane? Methods: Seven persons with transfemoral amputation with medium residual limb length participated in this study. The prosthetic alignment in the sagittal plane was performed according to established recommendations. SAC varied (0°, 3°, 6°, 9°). Kinematic and kinetic parameters were recorded in a gait laboratory with a 12-camera optoelectronic system and two piezoelectric force plates embedded in a 12-m walkway. The measurements were performed during level ground walking with self-selected comfortable gait speed. Results: In the frontal plane, nearly all investigated kinematic and kinetic parameters showed a strong correlation with the SAC. The pelvis was raised on the contralateral side throughout the gait cycle with increasing SAC. During the prosthetic side stance phase, the mean shoulder obliquity and mean lateral trunk lean to the prosthetic side tended to be reduced with increased SAC. Prosthetic side hip abduction moment decreased with increasing SAC. Significance: The results confirm that transfemoral SAC contributes to pelvic stabilization and reduced compensatory movements of the pelvis and trunk. Transfemoral SAC of 6 ± 1° for bench alignment seems adequate for amputees with medium residual limb length. However, the optimum value for the individual patient may differ slightly.
Yazdani, M.; Hajiaghaei, B.; Saeedi, H.; Kamali, M.; Yousefi, M.
In: Curr. Orthop. Pract., Bd. 32, Nr. 5, S. 505–511, 2021, ISSN: 1940-7041.
@article{Yazdani2021,
title = {Does the socket design affect symmetry and spatiotemporal gait parameters? A case series of two transfemoral amputees},
author = {M. Yazdani and B. Hajiaghaei and H. Saeedi and M. Kamali and M. Yousefi},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L635549609&from=export},
doi = {10.1097/bco.0000000000001022},
issn = {1940-7041},
year = {2021},
date = {2021-01-01},
journal = {Curr. Orthop. Pract.},
volume = {32},
number = {5},
pages = {505–511},
address = {B. Hajiaghaei, Department of Orthotics and Prosthetics, School of Rehabilitation Sciences, Iran University of Medical Sciences, Nezam Ave, Tehran, Iran},
abstract = {Background: Socket design is thought to improve gait performance and symmetry as the other components of the prosthesis do. This study focused on the comparison of two different sockets in transfemoral amputee patients to evaluate the influence of the socket designs on gait symmetry and various spatiotemporal gait parameters. Methods: Two transfemoral amputees participated in this case series study. They were asked to walk with the quadrilateral and the new modified sockets along a 10-meter walkway. The marker-based motion capture system recorded the spatiotemporal gait data during all walking trials. Kinematic data were compared between the two test conditions using the Wilcoxon signed-rank test and Symmetry Index. Results: The new socket increased velocity and cadence and reduced step width in both amputees, compared with the quadrilateral sockets. However, a good symmetry was observed in step length, stride length, step time, and stride time within two limbs by both sockets (SI ≤10). Conclusions: The design of sockets in this study had no observed effect on gait symmetry; however, the new socket increased velocity and cadence and reduced width step in both patients compared with the quadrilateral socket. Level of Evidence: Level IV.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Socket design is thought to improve gait performance and symmetry as the other components of the prosthesis do. This study focused on the comparison of two different sockets in transfemoral amputee patients to evaluate the influence of the socket designs on gait symmetry and various spatiotemporal gait parameters. Methods: Two transfemoral amputees participated in this case series study. They were asked to walk with the quadrilateral and the new modified sockets along a 10-meter walkway. The marker-based motion capture system recorded the spatiotemporal gait data during all walking trials. Kinematic data were compared between the two test conditions using the Wilcoxon signed-rank test and Symmetry Index. Results: The new socket increased velocity and cadence and reduced step width in both amputees, compared with the quadrilateral sockets. However, a good symmetry was observed in step length, stride length, step time, and stride time within two limbs by both sockets (SI ≤10). Conclusions: The design of sockets in this study had no observed effect on gait symmetry; however, the new socket increased velocity and cadence and reduced width step in both patients compared with the quadrilateral socket. Level of Evidence: Level IV.
2020
Ernst, M.; Altenburg, B.; Schmalz, T.
Characterizing adaptations of prosthetic feet in the frontal plane Artikel
In: Prosthet. Orthot. Int., Bd. 44, Nr. 4, S. 225–233, 2020, ISSN: 0309-3646.
@article{Ernst2020,
title = {Characterizing adaptations of prosthetic feet in the frontal plane},
author = {M. Ernst and B. Altenburg and T. Schmalz},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2005154580&from=export},
doi = {10.1177/0309364620917838},
issn = {0309-3646},
year = {2020},
date = {2020-01-01},
journal = {Prosthet. Orthot. Int.},
volume = {44},
number = {4},
pages = {225–233},
address = {M. Ernst, Research Biomechanics, Clinical Research and Services, Ottobock SE Co. KGaA, Göttingen, Germany},
abstract = {Background: Energy-storage and return feet incorporate various design features including split toes. As a potential improvement, an energy-storage and return foot with a dedicated ankle joint was recently introduced allowing for easily accessible inversion/eversion movement. However, the adaptability of energy-storage and return feet to uneven ground and the effects on biomechanical and clinical parameters have not been investigated in detail. Objectives: To investigate the design-related ability of prosthetic feet to adapt to cross slopes and derive a theoretical model. Study design: Mechanical testing and characterization. Methods: Mechanical adaptation to cross slopes was investigated for six prosthetic feet measured by a motion capture system. A theoretical model linking the measured data with adaptations is proposed. Results: The type and degree of adaptation depends on the foot design, for example, stiffness, split toe or continuous carbon forefoot, and additional ankle joint. The model used shows high correlations with the measured data for all feet. Conclusions: The ability of prosthetic feet to adapt to uneven ground is design-dependent. The split-toe feet adapted better to cross slopes than those with continuous carbon forefeet. Joints enhance this further by allowing for additional inversion and eversion. The influence on biomechanical and clinical parameters should be assessed in future studies. Clinical relevance: Knowing foot-specific ability to adapt to uneven ground may help in selecting an appropriate prosthetic foot for persons with a lower limb amputation. Faster and more comprehensive adaptations to uneven ground may lower the need for compensations and therefore increase user safety.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Energy-storage and return feet incorporate various design features including split toes. As a potential improvement, an energy-storage and return foot with a dedicated ankle joint was recently introduced allowing for easily accessible inversion/eversion movement. However, the adaptability of energy-storage and return feet to uneven ground and the effects on biomechanical and clinical parameters have not been investigated in detail. Objectives: To investigate the design-related ability of prosthetic feet to adapt to cross slopes and derive a theoretical model. Study design: Mechanical testing and characterization. Methods: Mechanical adaptation to cross slopes was investigated for six prosthetic feet measured by a motion capture system. A theoretical model linking the measured data with adaptations is proposed. Results: The type and degree of adaptation depends on the foot design, for example, stiffness, split toe or continuous carbon forefoot, and additional ankle joint. The model used shows high correlations with the measured data for all feet. Conclusions: The ability of prosthetic feet to adapt to uneven ground is design-dependent. The split-toe feet adapted better to cross slopes than those with continuous carbon forefeet. Joints enhance this further by allowing for additional inversion and eversion. The influence on biomechanical and clinical parameters should be assessed in future studies. Clinical relevance: Knowing foot-specific ability to adapt to uneven ground may help in selecting an appropriate prosthetic foot for persons with a lower limb amputation. Faster and more comprehensive adaptations to uneven ground may lower the need for compensations and therefore increase user safety.
2014
Whitehead, J. M. Aldridge; Wolf, E. J.; Scoville, C. R.; Wilken, J. M.
In: Clin. Orthop. Relat. Res., Bd. 472, Nr. 10, S. 3093–3101, 2014, ISSN: 0009-921X.
@article{AldridgeWhitehead2014,
title = {Does a Microprocessor-controlled Prosthetic Knee Affect Stair Ascent Strategies in Persons With Transfemoral Amputation?},
author = {J. M. Aldridge Whitehead and E. J. Wolf and C. R. Scoville and J. M. Wilken},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L608263443&from=export},
doi = {10.1007/s11999-014-3484-2},
issn = {0009-921X},
year = {2014},
date = {2014-10-01},
journal = {Clin. Orthop. Relat. Res.},
volume = {472},
number = {10},
pages = {3093–3101},
publisher = {Ovid Technologies (Wolters Kluwer Health)},
address = {J.M. Wilken, DOD-VA Extremity Trauma and Amputation Center of Excellence, Center for the Intrepid, Department of Orthopaedics and Rehabilitation, Brooke Army Medical Center, 3551 Roger Brooke Drive, Ft Sam Houston, TX, United States},
abstract = {Background: Stair ascent can be difficult for individuals with transfemoral amputation because of the loss of knee function. Most individuals with transfemoral amputation use either a step-to-step (nonreciprocal, advancing one stair at a time) or skip-step strategy (nonreciprocal, advancing two stairs at a time), rather than a step-over-step (reciprocal) strategy, because step-to-step and skip-step allow the leading intact limb to do the majority of work. A new microprocessor-controlled knee (Ottobock X2®) uses flexion/extension resistance to allow step-over-step stair ascent. Questions/Purposes: We compared self-selected stair ascent strategies between conventional and X2® prosthetic knees, examined between-limb differences, and differentiated stair ascent mechanics between X2® users and individuals without amputation. We also determined which factors are associated with differences in knee position during initial contact and swing within X2® users. Methods: Fourteen individuals with transfemoral amputation participated in stair ascent sessions while using conventional and X2® knees. Ten individuals without amputation also completed a stair ascent session. Lower-extremity stair ascent joint angles, moment, and powers and ground reaction forces were calculated using inverse dynamics during self-selected strategy and cadence and controlled cadence using a step-over-step strategy. Results: One individual with amputation self-selected a step-over-step strategy while using a conventional knee, while 10 individuals self-selected a step-over-step strategy while using X2® knees. Individuals with amputation used greater prosthetic knee flexion during initial contact (32.5°},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: Stair ascent can be difficult for individuals with transfemoral amputation because of the loss of knee function. Most individuals with transfemoral amputation use either a step-to-step (nonreciprocal, advancing one stair at a time) or skip-step strategy (nonreciprocal, advancing two stairs at a time), rather than a step-over-step (reciprocal) strategy, because step-to-step and skip-step allow the leading intact limb to do the majority of work. A new microprocessor-controlled knee (Ottobock X2®) uses flexion/extension resistance to allow step-over-step stair ascent. Questions/Purposes: We compared self-selected stair ascent strategies between conventional and X2® prosthetic knees, examined between-limb differences, and differentiated stair ascent mechanics between X2® users and individuals without amputation. We also determined which factors are associated with differences in knee position during initial contact and swing within X2® users. Methods: Fourteen individuals with transfemoral amputation participated in stair ascent sessions while using conventional and X2® knees. Ten individuals without amputation also completed a stair ascent session. Lower-extremity stair ascent joint angles, moment, and powers and ground reaction forces were calculated using inverse dynamics during self-selected strategy and cadence and controlled cadence using a step-over-step strategy. Results: One individual with amputation self-selected a step-over-step strategy while using a conventional knee, while 10 individuals self-selected a step-over-step strategy while using X2® knees. Individuals with amputation used greater prosthetic knee flexion during initial contact (32.5°