TPress
1.
Waterval, N. F. J.; Brehm, M. -A.; Harlaar, J.; Nollet, F.
In: J. NeuroEng. Rehabil., Bd. 18, Nr. 1, 2021, ISSN: 1743-0003.
Abstract | Links | Schlagwörter: adult, ankle foot orthosis, article, body weight, Carbon Ankle7, clinical effectiveness, correlational study, dorsal leaf spring ankle foot orthosis, energy cost, female, human, male, middle aged, muscle strength, muscle weakness, range of motion, risk factor, triceps surae muscle, walking speed
@article{Waterval2021,
title = {Individual stiffness optimization of dorsal leaf spring ankle-foot orthoses in people with calf muscle weakness is superior to standard bodyweight-based recommendations},
author = {N. F. J. Waterval and M. -A. Brehm and J. Harlaar and F. Nollet},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2012344314&from=export},
doi = {10.1186/s12984-021-00890-8},
issn = {1743-0003},
year = {2021},
date = {2021-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {18},
number = {1},
address = {N.F.J. Waterval, Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, Netherlands},
abstract = {Background: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s},
keywords = {adult, ankle foot orthosis, article, body weight, Carbon Ankle7, clinical effectiveness, correlational study, dorsal leaf spring ankle foot orthosis, energy cost, female, human, male, middle aged, muscle strength, muscle weakness, range of motion, risk factor, triceps surae muscle, walking speed},
pubstate = {published},
tppubtype = {article}
}
Background: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s
2.
Rigney, S. M.; Simmons, A.; Kark, L.
Mechanical characterization and comparison of energy storage and return prostheses Artikel
In: Med. Eng. Phys., Bd. 41, S. 90–96, 2017, ISSN: 1350-4533.
Abstract | Links | Schlagwörter: 1E90 Sprinter, article, biomechanics, body weight, Cheetah Xtreme, comparative study, controlled study, female, finite element analysis, Flex-foot Cheetah, foot prosthesis, force, gait, human, human experiment, mechanical torsion, rigidity, simulation, Vari-flex Modular
@article{Rigney2017,
title = {Mechanical characterization and comparison of energy storage and return prostheses},
author = {S. M. Rigney and A. Simmons and L. Kark},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L614136635&from=export},
doi = {10.1016/j.medengphy.2017.01.003},
issn = {1350-4533},
year = {2017},
date = {2017-01-01},
journal = {Med. Eng. Phys.},
volume = {41},
pages = {90–96},
address = {L. Kark, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia},
abstract = {The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex® ModularTM, Flex-foot Cheetah and Cheetah Xtreme by Össur® and a 1E90 Sprinter by Ottobock®. Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics®, where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses’ loading response under bodyweight for an 80 kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0 Nmm−1 for the Vari-flex® ModularTM, Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics.},
keywords = {1E90 Sprinter, article, biomechanics, body weight, Cheetah Xtreme, comparative study, controlled study, female, finite element analysis, Flex-foot Cheetah, foot prosthesis, force, gait, human, human experiment, mechanical torsion, rigidity, simulation, Vari-flex Modular},
pubstate = {published},
tppubtype = {article}
}
The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex® ModularTM, Flex-foot Cheetah and Cheetah Xtreme by Össur® and a 1E90 Sprinter by Ottobock®. Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics®, where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses’ loading response under bodyweight for an 80 kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0 Nmm−1 for the Vari-flex® ModularTM, Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics.
3.
Komolafe, O.; Wood, S.; Caldwell, R.; Hansen, A.; Fatone, S.
Methods for characterization of mechanical and electrical prosthetic vacuum pumps Artikel
In: J. Rehabil. Res. Dev., Bd. 50, Nr. 8, S. 1069–1078, 2013, ISSN: 1938-1352.
Abstract | Links | Schlagwörter: article, atmospheric pressure, body weight, electrical prosthetic vacuum pump, humidity, measurement, mechanical prosthetic vacuum pump, microprocessor, pressure transducer, priority journal, prosthesis material
@article{Komolafe2013,
title = {Methods for characterization of mechanical and electrical prosthetic vacuum pumps},
author = {O. Komolafe and S. Wood and R. Caldwell and A. Hansen and S. Fatone},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L370540897&from=export},
doi = {10.1682/jrrd.2012.11.0204},
issn = {1938-1352},
year = {2013},
date = {2013-01-01},
journal = {J. Rehabil. Res. Dev.},
volume = {50},
number = {8},
pages = {1069–1078},
address = {S. Fatone, Northwestern University, Prosthetics-Orthotics Center, 680 N Lake Shore Dr, Suite 1100, Chicago, IL 60611, United States},
abstract = {Despite increasingly widespread adoption of vacuum- assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3) to 197 cm3 (12 in.3) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.},
keywords = {article, atmospheric pressure, body weight, electrical prosthetic vacuum pump, humidity, measurement, mechanical prosthetic vacuum pump, microprocessor, pressure transducer, priority journal, prosthesis material},
pubstate = {published},
tppubtype = {article}
}
Despite increasingly widespread adoption of vacuum- assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3) to 197 cm3 (12 in.3) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.
2021
Waterval, N. F. J.; Brehm, M. -A.; Harlaar, J.; Nollet, F.
In: J. NeuroEng. Rehabil., Bd. 18, Nr. 1, 2021, ISSN: 1743-0003.
Abstract | Links | Schlagwörter: adult, ankle foot orthosis, article, body weight, Carbon Ankle7, clinical effectiveness, correlational study, dorsal leaf spring ankle foot orthosis, energy cost, female, human, male, middle aged, muscle strength, muscle weakness, range of motion, risk factor, triceps surae muscle, walking speed
@article{Waterval2021,
title = {Individual stiffness optimization of dorsal leaf spring ankle-foot orthoses in people with calf muscle weakness is superior to standard bodyweight-based recommendations},
author = {N. F. J. Waterval and M. -A. Brehm and J. Harlaar and F. Nollet},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2012344314&from=export},
doi = {10.1186/s12984-021-00890-8},
issn = {1743-0003},
year = {2021},
date = {2021-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {18},
number = {1},
address = {N.F.J. Waterval, Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, Netherlands},
abstract = {Background: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s},
keywords = {adult, ankle foot orthosis, article, body weight, Carbon Ankle7, clinical effectiveness, correlational study, dorsal leaf spring ankle foot orthosis, energy cost, female, human, male, middle aged, muscle strength, muscle weakness, range of motion, risk factor, triceps surae muscle, walking speed},
pubstate = {published},
tppubtype = {article}
}
Background: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s
2017
Rigney, S. M.; Simmons, A.; Kark, L.
Mechanical characterization and comparison of energy storage and return prostheses Artikel
In: Med. Eng. Phys., Bd. 41, S. 90–96, 2017, ISSN: 1350-4533.
Abstract | Links | Schlagwörter: 1E90 Sprinter, article, biomechanics, body weight, Cheetah Xtreme, comparative study, controlled study, female, finite element analysis, Flex-foot Cheetah, foot prosthesis, force, gait, human, human experiment, mechanical torsion, rigidity, simulation, Vari-flex Modular
@article{Rigney2017,
title = {Mechanical characterization and comparison of energy storage and return prostheses},
author = {S. M. Rigney and A. Simmons and L. Kark},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L614136635&from=export},
doi = {10.1016/j.medengphy.2017.01.003},
issn = {1350-4533},
year = {2017},
date = {2017-01-01},
journal = {Med. Eng. Phys.},
volume = {41},
pages = {90–96},
address = {L. Kark, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia},
abstract = {The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex® ModularTM, Flex-foot Cheetah and Cheetah Xtreme by Össur® and a 1E90 Sprinter by Ottobock®. Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics®, where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses’ loading response under bodyweight for an 80 kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0 Nmm−1 for the Vari-flex® ModularTM, Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics.},
keywords = {1E90 Sprinter, article, biomechanics, body weight, Cheetah Xtreme, comparative study, controlled study, female, finite element analysis, Flex-foot Cheetah, foot prosthesis, force, gait, human, human experiment, mechanical torsion, rigidity, simulation, Vari-flex Modular},
pubstate = {published},
tppubtype = {article}
}
The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex® ModularTM, Flex-foot Cheetah and Cheetah Xtreme by Össur® and a 1E90 Sprinter by Ottobock®. Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics®, where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses’ loading response under bodyweight for an 80 kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0 Nmm−1 for the Vari-flex® ModularTM, Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics.
2013
Komolafe, O.; Wood, S.; Caldwell, R.; Hansen, A.; Fatone, S.
Methods for characterization of mechanical and electrical prosthetic vacuum pumps Artikel
In: J. Rehabil. Res. Dev., Bd. 50, Nr. 8, S. 1069–1078, 2013, ISSN: 1938-1352.
Abstract | Links | Schlagwörter: article, atmospheric pressure, body weight, electrical prosthetic vacuum pump, humidity, measurement, mechanical prosthetic vacuum pump, microprocessor, pressure transducer, priority journal, prosthesis material
@article{Komolafe2013,
title = {Methods for characterization of mechanical and electrical prosthetic vacuum pumps},
author = {O. Komolafe and S. Wood and R. Caldwell and A. Hansen and S. Fatone},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L370540897&from=export},
doi = {10.1682/jrrd.2012.11.0204},
issn = {1938-1352},
year = {2013},
date = {2013-01-01},
journal = {J. Rehabil. Res. Dev.},
volume = {50},
number = {8},
pages = {1069–1078},
address = {S. Fatone, Northwestern University, Prosthetics-Orthotics Center, 680 N Lake Shore Dr, Suite 1100, Chicago, IL 60611, United States},
abstract = {Despite increasingly widespread adoption of vacuum- assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3) to 197 cm3 (12 in.3) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.},
keywords = {article, atmospheric pressure, body weight, electrical prosthetic vacuum pump, humidity, measurement, mechanical prosthetic vacuum pump, microprocessor, pressure transducer, priority journal, prosthesis material},
pubstate = {published},
tppubtype = {article}
}
Despite increasingly widespread adoption of vacuum- assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3) to 197 cm3 (12 in.3) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.
2021
Waterval, N. F. J.; Brehm, M. -A.; Harlaar, J.; Nollet, F.
In: J. NeuroEng. Rehabil., Bd. 18, Nr. 1, 2021, ISSN: 1743-0003.
@article{Waterval2021,
title = {Individual stiffness optimization of dorsal leaf spring ankle-foot orthoses in people with calf muscle weakness is superior to standard bodyweight-based recommendations},
author = {N. F. J. Waterval and M. -A. Brehm and J. Harlaar and F. Nollet},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2012344314&from=export},
doi = {10.1186/s12984-021-00890-8},
issn = {1743-0003},
year = {2021},
date = {2021-01-01},
journal = {J. NeuroEng. Rehabil.},
volume = {18},
number = {1},
address = {N.F.J. Waterval, Rehabilitation Medicine, Amsterdam Movement Sciences, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, Netherlands},
abstract = {Background: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: In people with calf muscle weakness, the stiffness of dorsal leaf spring ankle-foot orthoses (DLS-AFO) needs to be individualized to maximize its effect on walking. Orthotic suppliers may recommend a certain stiffness based on body weight and activity level. However, it is unknown whether these recommendations are sufficient to yield the optimal stiffness for the individual. Therefore, we assessed whether the stiffness following the supplier’s recommendation of the Carbon Ankle7 (CA7) dorsal leaf matched the experimentally optimized AFO stiffness. Methods: Thirty-four persons with calf muscle weakness were included and provided a new DLS-AFO of which the stiffness could be varied by changing the CA7® (Ottobock, Duderstadt, Germany) dorsal leaf. For five different stiffness levels, including the supplier recommended stiffness, gait biomechanics, walking energy cost and speed were assessed. Based on these measures, the individual experimentally optimal AFO stiffness was selected. Results: In only 8 of 34 (23%) participants, the supplier recommended stiffness matched the experimentally optimized AFO stiffness, the latter being on average 1.2 ± 1.3 Nm/degree more flexible. The DLS-AFO with an experimentally optimized stiffness resulted in a significantly lower walking energy cost (− 0.21 ± 0.26 J/kg/m, p < 0.001) and a higher speed (+ 0.02 m/s
2017
Rigney, S. M.; Simmons, A.; Kark, L.
Mechanical characterization and comparison of energy storage and return prostheses Artikel
In: Med. Eng. Phys., Bd. 41, S. 90–96, 2017, ISSN: 1350-4533.
@article{Rigney2017,
title = {Mechanical characterization and comparison of energy storage and return prostheses},
author = {S. M. Rigney and A. Simmons and L. Kark},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L614136635&from=export},
doi = {10.1016/j.medengphy.2017.01.003},
issn = {1350-4533},
year = {2017},
date = {2017-01-01},
journal = {Med. Eng. Phys.},
volume = {41},
pages = {90–96},
address = {L. Kark, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, NSW, Australia},
abstract = {The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex® ModularTM, Flex-foot Cheetah and Cheetah Xtreme by Össur® and a 1E90 Sprinter by Ottobock®. Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics®, where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses’ loading response under bodyweight for an 80 kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0 Nmm−1 for the Vari-flex® ModularTM, Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The suitability of finite element analysis (FEA) for standardizing the mechanical characterization of energy storage and return (ESAR) prostheses was investigated. A methodology consisting of both experimental and numerical analysis was proposed and trialed for the Vari-flex® ModularTM, Flex-foot Cheetah and Cheetah Xtreme by Össur® and a 1E90 Sprinter by Ottobock®. Gait analysis was conducted to determine suitable orientation angles for non-destructive testing (NDT) of the ESAR prostheses followed by a quasi-static inverse FEA procedure within COMSOL Multiphysics®, where the NDT conditions were replicated to determine the homogenized material properties of the prostheses. The prostheses’ loading response under bodyweight for an 80 kg person was then simulated, using both Eigenfrequency and time-dependent analysis. The apparent stiffness under bodyweight was determined to be 94.7, 48.6, 57.4 and 65.0 Nmm−1 for the Vari-flex® ModularTM, Flex-foot Cheetah, Cheetah Xtreme and 1E90 Sprinter, respectively. Both the energy stored and returned by the prostheses varied negatively with stiffness, yet the overall efficiency of the prostheses were similar, at 52.7, 52.0, 51.7 and 52.4% for the abovementioned prostheses. The proposed methodology allows the standardized assessment and comparison of ESAR prostheses without the confounding influences of subject-specific gait characteristics.
2013
Komolafe, O.; Wood, S.; Caldwell, R.; Hansen, A.; Fatone, S.
Methods for characterization of mechanical and electrical prosthetic vacuum pumps Artikel
In: J. Rehabil. Res. Dev., Bd. 50, Nr. 8, S. 1069–1078, 2013, ISSN: 1938-1352.
@article{Komolafe2013,
title = {Methods for characterization of mechanical and electrical prosthetic vacuum pumps},
author = {O. Komolafe and S. Wood and R. Caldwell and A. Hansen and S. Fatone},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L370540897&from=export},
doi = {10.1682/jrrd.2012.11.0204},
issn = {1938-1352},
year = {2013},
date = {2013-01-01},
journal = {J. Rehabil. Res. Dev.},
volume = {50},
number = {8},
pages = {1069–1078},
address = {S. Fatone, Northwestern University, Prosthetics-Orthotics Center, 680 N Lake Shore Dr, Suite 1100, Chicago, IL 60611, United States},
abstract = {Despite increasingly widespread adoption of vacuum- assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3) to 197 cm3 (12 in.3) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Despite increasingly widespread adoption of vacuum- assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm3 (2 in.3) to 197 cm3 (12 in.3) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.