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.
Hahn, A.; Lang, M.; Stuckart, C.
In: Medicine, Bd. 95, Nr. 45, 2016, ISSN: 0025-7974.
Abstract | Links | Schlagwörter: above knee prosthesis, adult, amputee, article, C-leg, climbing, cohort analysis, female, gait, Genium, human, major clinical study, male, mobilization, patient attitude, priority journal, retrospective study, toileting, walking
@article{Hahn2016,
title = {Analysis of clinically important factors on the performance of advanced hydraulic, microprocessor-controlled exo-prosthetic knee joints based on 899 trial fittings},
author = {A. Hahn and M. Lang and C. Stuckart},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L613375887&from=export},
doi = {10.1097/md.0000000000005386},
issn = {0025-7974},
year = {2016},
date = {2016-01-01},
journal = {Medicine},
volume = {95},
number = {45},
address = {A. Hahn, Otto Bock Healthcare Products GmbH, Brehmstrasse 16, Vienna, Austria},
abstract = {The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.},
keywords = {above knee prosthesis, adult, amputee, article, C-leg, climbing, cohort analysis, female, gait, Genium, human, major clinical study, male, mobilization, patient attitude, priority journal, retrospective study, toileting, walking},
pubstate = {published},
tppubtype = {article}
}
The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.
3.
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.
Abstract | Links | Schlagwörter: above knee prosthesis, adult, amputation, article, C- Leg, clinical article, controlled study, femur, functional assessment, ground reaction force, human, joint function, kinematics, male, microprocessor, microprocessor controlled prosthetic knee, motion analysis system, priority journal, Total Knee, walking, X2
@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 = {above knee prosthesis, adult, amputation, article, C- Leg, clinical article, controlled study, femur, functional assessment, ground reaction force, human, joint function, kinematics, male, microprocessor, microprocessor controlled prosthetic knee, motion analysis system, priority journal, Total Knee, walking, X2},
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°
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.
2016
Hahn, A.; Lang, M.; Stuckart, C.
In: Medicine, Bd. 95, Nr. 45, 2016, ISSN: 0025-7974.
Abstract | Links | Schlagwörter: above knee prosthesis, adult, amputee, article, C-leg, climbing, cohort analysis, female, gait, Genium, human, major clinical study, male, mobilization, patient attitude, priority journal, retrospective study, toileting, walking
@article{Hahn2016,
title = {Analysis of clinically important factors on the performance of advanced hydraulic, microprocessor-controlled exo-prosthetic knee joints based on 899 trial fittings},
author = {A. Hahn and M. Lang and C. Stuckart},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L613375887&from=export},
doi = {10.1097/md.0000000000005386},
issn = {0025-7974},
year = {2016},
date = {2016-01-01},
journal = {Medicine},
volume = {95},
number = {45},
address = {A. Hahn, Otto Bock Healthcare Products GmbH, Brehmstrasse 16, Vienna, Austria},
abstract = {The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.},
keywords = {above knee prosthesis, adult, amputee, article, C-leg, climbing, cohort analysis, female, gait, Genium, human, major clinical study, male, mobilization, patient attitude, priority journal, retrospective study, toileting, walking},
pubstate = {published},
tppubtype = {article}
}
The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.
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.
Abstract | Links | Schlagwörter: above knee prosthesis, adult, amputation, article, C- Leg, clinical article, controlled study, femur, functional assessment, ground reaction force, human, joint function, kinematics, male, microprocessor, microprocessor controlled prosthetic knee, motion analysis system, priority journal, Total Knee, walking, X2
@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 = {above knee prosthesis, adult, amputation, article, C- Leg, clinical article, controlled study, femur, functional assessment, ground reaction force, human, joint function, kinematics, male, microprocessor, microprocessor controlled prosthetic knee, motion analysis system, priority journal, Total Knee, walking, X2},
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°
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.
2016
Hahn, A.; Lang, M.; Stuckart, C.
In: Medicine, Bd. 95, Nr. 45, 2016, ISSN: 0025-7974.
@article{Hahn2016,
title = {Analysis of clinically important factors on the performance of advanced hydraulic, microprocessor-controlled exo-prosthetic knee joints based on 899 trial fittings},
author = {A. Hahn and M. Lang and C. Stuckart},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L613375887&from=export},
doi = {10.1097/md.0000000000005386},
issn = {0025-7974},
year = {2016},
date = {2016-01-01},
journal = {Medicine},
volume = {95},
number = {45},
address = {A. Hahn, Otto Bock Healthcare Products GmbH, Brehmstrasse 16, Vienna, Austria},
abstract = {The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The objective of this work is to evaluate whether clinically important factors may predict an individual's capability to utilize the functional benefits provided by an advanced hydraulic, microprocessor-controlled exo-prosthetic knee component. This retrospective cross-sectional cohort analysis investigated the data of above knee amputees captured during routine trial fittings. Prosthetists rated the performance indicators showing the functional benefits of the advanced maneuvering capabilities of the device. Subjects were asked to rate their perception. Simple and multiple linear and logistic regression was applied. Data from 899 subjects with demographics typical for the population were evaluated. Ability to vary gait speed, perform toileting, and ascend stairs were identified as the most sensitive performance predictors. Prior C-Leg users showed benefits during advanced maneuvering. Variables showed plausible and meaningful effects, however, could not claim predictive power. Mobility grade showed the largest effect but also failed to be predictive. Clinical parameters such as etiology, age, mobility grade, and others analyzed here do not suffice to predict individual potential. Daily walking distance may pose a threshold value and be part of a predictive instrument. Decisions based solely on single parameters such as mobility grade rating or walking distance seem to be questionable.
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°