TPress
1.
Taboga, P.; Beck, O. N.; Grabowski, A. M.
In: PLoS ONE, Bd. 15, Nr. 2, 2020, ISSN: 1932-6203.
Abstract | Links | Schlagwörter: adult, aerial time, article, athlete, below knee amputation, below knee prosthesis, biomechanics, clinical article, contact length, contact time, controlled study, Freedom Innovations Catapult FX6, ground reaction force, human, male, Ossur Flex-Foot Cheetah Xtend, Ottobock 1E90 Sprinter, physical parameters, prosthesis design, prosthetic height, prosthetic shape, prosthetic stiffness, running, running specific prosthesis, running speed, standing, vertical stiffness, young adult
@article{Taboga2020,
title = {Prosthetic shape, but not stiffness or height, affects the maximum speed of sprinters with bilateral transtibial amputations},
author = {P. Taboga and O. N. Beck and A. M. Grabowski},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2005026109&from=export},
doi = {10.1371/journal.pone.0229035},
issn = {1932-6203},
year = {2020},
date = {2020-01-01},
journal = {PLoS ONE},
volume = {15},
number = {2},
address = {P. Taboga, Department of Kinesiology, California State University, Sacramento, CA, United States},
abstract = {Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kNm-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.},
keywords = {adult, aerial time, article, athlete, below knee amputation, below knee prosthesis, biomechanics, clinical article, contact length, contact time, controlled study, Freedom Innovations Catapult FX6, ground reaction force, human, male, Ossur Flex-Foot Cheetah Xtend, Ottobock 1E90 Sprinter, physical parameters, prosthesis design, prosthetic height, prosthetic shape, prosthetic stiffness, running, running specific prosthesis, running speed, standing, vertical stiffness, young adult},
pubstate = {published},
tppubtype = {article}
}
Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kNm-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.
2.
Beck, O. N.; Taboga, P.; Grabowski, A. M.
Characterizing the mechanical properties of running-specific prostheses Artikel
In: PLoS ONE, Bd. 11, Nr. 12, 2016, ISSN: 1932-6203.
Abstract | Links | Schlagwörter: 1E90 Sprinter, adult, amputation, article, athlete, body mass, Catapult FX6, Cheetah Xtend, clinical article, controlled study, female, Flex-Run, foot prosthesis, human, hysteresis, male, materials testing, mechanics, prosthesis design, prosthesis material, prosthetic force displacement, prosthetic height, prosthetic stiffness, running, running specific prosthesis, Sprinter, transtibial amputation
@article{Beck2016,
title = {Characterizing the mechanical properties of running-specific prostheses},
author = {O. N. Beck and P. Taboga and A. M. Grabowski},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L613668924&from=export},
doi = {10.1371/journal.pone.0168298},
issn = {1932-6203},
year = {2016},
date = {2016-01-01},
journal = {PLoS ONE},
volume = {11},
number = {12},
abstract = {The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10?-25?) compared to neutral (0?) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/ or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness.},
keywords = {1E90 Sprinter, adult, amputation, article, athlete, body mass, Catapult FX6, Cheetah Xtend, clinical article, controlled study, female, Flex-Run, foot prosthesis, human, hysteresis, male, materials testing, mechanics, prosthesis design, prosthesis material, prosthetic force displacement, prosthetic height, prosthetic stiffness, running, running specific prosthesis, Sprinter, transtibial amputation},
pubstate = {published},
tppubtype = {article}
}
The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10?-25?) compared to neutral (0?) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/ or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness.
2020
Taboga, P.; Beck, O. N.; Grabowski, A. M.
In: PLoS ONE, Bd. 15, Nr. 2, 2020, ISSN: 1932-6203.
Abstract | Links | Schlagwörter: adult, aerial time, article, athlete, below knee amputation, below knee prosthesis, biomechanics, clinical article, contact length, contact time, controlled study, Freedom Innovations Catapult FX6, ground reaction force, human, male, Ossur Flex-Foot Cheetah Xtend, Ottobock 1E90 Sprinter, physical parameters, prosthesis design, prosthetic height, prosthetic shape, prosthetic stiffness, running, running specific prosthesis, running speed, standing, vertical stiffness, young adult
@article{Taboga2020,
title = {Prosthetic shape, but not stiffness or height, affects the maximum speed of sprinters with bilateral transtibial amputations},
author = {P. Taboga and O. N. Beck and A. M. Grabowski},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2005026109&from=export},
doi = {10.1371/journal.pone.0229035},
issn = {1932-6203},
year = {2020},
date = {2020-01-01},
journal = {PLoS ONE},
volume = {15},
number = {2},
address = {P. Taboga, Department of Kinesiology, California State University, Sacramento, CA, United States},
abstract = {Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kNm-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.},
keywords = {adult, aerial time, article, athlete, below knee amputation, below knee prosthesis, biomechanics, clinical article, contact length, contact time, controlled study, Freedom Innovations Catapult FX6, ground reaction force, human, male, Ossur Flex-Foot Cheetah Xtend, Ottobock 1E90 Sprinter, physical parameters, prosthesis design, prosthetic height, prosthetic shape, prosthetic stiffness, running, running specific prosthesis, running speed, standing, vertical stiffness, young adult},
pubstate = {published},
tppubtype = {article}
}
Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kNm-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.
2016
Beck, O. N.; Taboga, P.; Grabowski, A. M.
Characterizing the mechanical properties of running-specific prostheses Artikel
In: PLoS ONE, Bd. 11, Nr. 12, 2016, ISSN: 1932-6203.
Abstract | Links | Schlagwörter: 1E90 Sprinter, adult, amputation, article, athlete, body mass, Catapult FX6, Cheetah Xtend, clinical article, controlled study, female, Flex-Run, foot prosthesis, human, hysteresis, male, materials testing, mechanics, prosthesis design, prosthesis material, prosthetic force displacement, prosthetic height, prosthetic stiffness, running, running specific prosthesis, Sprinter, transtibial amputation
@article{Beck2016,
title = {Characterizing the mechanical properties of running-specific prostheses},
author = {O. N. Beck and P. Taboga and A. M. Grabowski},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L613668924&from=export},
doi = {10.1371/journal.pone.0168298},
issn = {1932-6203},
year = {2016},
date = {2016-01-01},
journal = {PLoS ONE},
volume = {11},
number = {12},
abstract = {The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10?-25?) compared to neutral (0?) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/ or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness.},
keywords = {1E90 Sprinter, adult, amputation, article, athlete, body mass, Catapult FX6, Cheetah Xtend, clinical article, controlled study, female, Flex-Run, foot prosthesis, human, hysteresis, male, materials testing, mechanics, prosthesis design, prosthesis material, prosthetic force displacement, prosthetic height, prosthetic stiffness, running, running specific prosthesis, Sprinter, transtibial amputation},
pubstate = {published},
tppubtype = {article}
}
The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10?-25?) compared to neutral (0?) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/ or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness.
2020
Taboga, P.; Beck, O. N.; Grabowski, A. M.
In: PLoS ONE, Bd. 15, Nr. 2, 2020, ISSN: 1932-6203.
@article{Taboga2020,
title = {Prosthetic shape, but not stiffness or height, affects the maximum speed of sprinters with bilateral transtibial amputations},
author = {P. Taboga and O. N. Beck and A. M. Grabowski},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L2005026109&from=export},
doi = {10.1371/journal.pone.0229035},
issn = {1932-6203},
year = {2020},
date = {2020-01-01},
journal = {PLoS ONE},
volume = {15},
number = {2},
address = {P. Taboga, Department of Kinesiology, California State University, Sacramento, CA, United States},
abstract = {Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kNm-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Running-specific prostheses (RSPs) have facilitated an athlete with bilateral transtibial amputations to compete in the Olympic Games. However, the performance effects of using RSPs compared to biological legs remains controversial. Further, the use of different prosthetic configurations such as shape, stiffness, and height likely influence performance. We determined the effects of using 15 different RSP configurations on the maximum speed of five male athletes with bilateral transtibial amputations. These athletes performed sets of running trials up to maximum speed using three different RSP models (Freedom Innovations Catapult FX6, Össur Flex-Foot Cheetah Xtend and Ottobock 1E90 Sprinter) each with five combinations of stiffness category and height. We measured ground reaction forces during each maximum speed trial to determine the biomechanical parameters associated with different RSP configurations and maximum sprinting speeds. Use of the J-shaped Cheetah Xtend and 1E90 Sprinter RSPs resulted in 8.3% and 8.0% (p<0.001) faster maximum speeds compared to the use of the C-shaped Catapult FX6 RSPs, respectively. Neither RSP stiffness expressed as a category (p = 0.836) nor as kNm-1 (p = 0.916) affected maximum speed. Further, prosthetic height had no effect on maximum speed (p = 0.762). Faster maximum speeds were associated with reduced ground contact time, aerial time, and overall leg stiffness, as well as with greater stance-average vertical ground reaction force, contact length, and vertical stiffness (p = 0.015 for aerial time, p<0.001 for all other variables). RSP shape, but not stiffness or height, influences the maximum speed of athletes with bilateral transtibial amputations.
2016
Beck, O. N.; Taboga, P.; Grabowski, A. M.
Characterizing the mechanical properties of running-specific prostheses Artikel
In: PLoS ONE, Bd. 11, Nr. 12, 2016, ISSN: 1932-6203.
@article{Beck2016,
title = {Characterizing the mechanical properties of running-specific prostheses},
author = {O. N. Beck and P. Taboga and A. M. Grabowski},
url = {https://www.embase.com/search/results?subaction=viewrecord&id=L613668924&from=export},
doi = {10.1371/journal.pone.0168298},
issn = {1932-6203},
year = {2016},
date = {2016-01-01},
journal = {PLoS ONE},
volume = {11},
number = {12},
abstract = {The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10?-25?) compared to neutral (0?) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/ or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The mechanical stiffness of running-specific prostheses likely affects the functional abilities of athletes with leg amputations. However, each prosthetic manufacturer recommends prostheses based on subjective stiffness categories rather than performance based metrics. The actual mechanical stiffness values of running-specific prostheses (i.e. kN/m) are unknown. Consequently, we sought to characterize and disseminate the stiffness values of running-specific prostheses so that researchers, clinicians, and athletes can objectively evaluate prosthetic function. We characterized the stiffness values of 55 running-specific prostheses across various models, stiffness categories, and heights using forces and angles representative of those measured from athletes with transtibial amputations during running. Characterizing prosthetic force-displacement profiles with a 2nd degree polynomial explained 4.4% more of the variance than a linear function (p<0.001). The prosthetic stiffness values of manufacturer recommended stiffness categories varied between prosthetic models (p<0.001). Also, prosthetic stiffness was 10% to 39% less at angles typical of running 3 m/s and 6 m/s (10?-25?) compared to neutral (0?) (p<0.001). Furthermore, prosthetic stiffness was inversely related to height in J-shaped (p<0.001), but not C-shaped, prostheses. Running-specific prostheses should be tested under the demands of the respective activity in order to derive relevant characterizations of stiffness and function. In all, our results indicate that when athletes with leg amputations alter prosthetic model, height, and/ or sagittal plane alignment, their prosthetic stiffness profiles also change; therefore variations in comfort, performance, etc. may be indirectly due to altered stiffness.