Purpose:The purpose of this study was to compare knee biomechanics of the replaced limb to the non-replaced limb of total knee replacement(TKR)patients and healthy controls during walking on level ground and on declin...Purpose:The purpose of this study was to compare knee biomechanics of the replaced limb to the non-replaced limb of total knee replacement(TKR)patients and healthy controls during walking on level ground and on decline surfaces of 5°,10°,and 15°.Methods:Twenty-five TKR patients and 10 healthy controls performed 5 walking trials on different decline slopes on a force platform and an instrumented ramp system.Two analyses of variance,2×2(limb×group)and 2×4(limb×decline slope),were used to examine selected biomechanics variables.Results:The replaced limb of TKR patients had lower peak loading-response and push-off knee extension moment than the non-replaced and the matched limb of healthy controls.No differences were found in loading-response and push-off knee internal abduction moments among replaced,non-replaced,and matched limb of healthy controls.The knee flexion range of motion,peak loading-response vertical ground reaction force,and peak knee extension moment increased across all slope comparisons between 0°and 15°in both the replaced and non-replaced limb of TKR patients.Conclusion:Downhill walking may not be appropriate to include in early stage rehabilitation exercise protocols for TKR patients.展开更多
Background: Q-Factor(QF), or the inter-pedal width, in cycling is similar to step-width in gait. Although increased step-width has been shown to reduce peak knee abduction moment(KAbM), no studies have examined the bi...Background: Q-Factor(QF), or the inter-pedal width, in cycling is similar to step-width in gait. Although increased step-width has been shown to reduce peak knee abduction moment(KAbM), no studies have examined the biomechanical effects of increased QF in cycling at different workrates in healthy participants.Methods: A total of 16 healthy participants(8 males, 8 females, age: 22.4 ± 2.6 years, body mass index: 22.78 ± 1.43 kg/m^2, mean ± SD) participated.A motion capture system and customized instrumented pedals were used to collect 3-dimensional kinematic(240 Hz) and pedal reaction force(PRF)(1200 Hz) data in 12 testing conditions: 4 QF conditions—Q1(15.0 cm), Q2(19.2 cm), Q3(23.4 cm), and Q4(27.6 cm)—under 3 workrate conditions—80 watts(W), 120 W, and 160 W. A 3 × 4(QF × workrate) repeated measures of analysis of variance were performed to analyze differences among conditions(p < 0.05).Results: Increased QF increased peak KAbM by 47%, 56%, and 56% from Q1 to Q4 at each respective workrate. Mediolateral PRF increased from Q1 to Q4 at each respective workrate. Frontal-plane knee angle and range of motion decreased with increased QF. No changes were observed for peak vertical PRF, knee extension moment, sagittal plane peak knee joint angles, or range of motion.Conclusion: Increased QF increased peak KAbM, suggesting increased medial compartment loading of the knee. QF modulation may influence frontal-plane joint loading when using stationary cycling for exercise or rehabilitation purposes.展开更多
目的探讨着鞋类型(裸足、普通鞋、极简鞋)与步行速度(快步走、常速行走)对膝关节生物力学指标的影响,为科学健身提供理论参考。方法采用Vicon三维运动捕捉系统、Kisler三维测力台同步采集10名男性在裸足、穿着不同鞋常速行走与快步走时...目的探讨着鞋类型(裸足、普通鞋、极简鞋)与步行速度(快步走、常速行走)对膝关节生物力学指标的影响,为科学健身提供理论参考。方法采用Vicon三维运动捕捉系统、Kisler三维测力台同步采集10名男性在裸足、穿着不同鞋常速行走与快步走时下肢运动生物力学指标。采用双因素(2种行走方式×3种着鞋类型)重复测量方差分析对各指标进行统计分析。结果相对于快步走,常速行走时足底压力中心(center of pressure,COP)向外偏移较大,额状面膝关节力臂、膝关节内收外力矩和第1峰值负载率均较小,但额状面膝关节冲量矩较大;相对于穿着普通跑鞋,裸足或穿着极简鞋时,步幅变小,COP向外偏移较大,额状面膝关节力臂、膝关节内收外力矩、第1峰值负载率和额状面膝关节冲量矩较小。结论为降低额状面膝关节冲量矩以及峰值负载率,建议着极简鞋采用小步幅进行快步走锻炼。展开更多
文摘Purpose:The purpose of this study was to compare knee biomechanics of the replaced limb to the non-replaced limb of total knee replacement(TKR)patients and healthy controls during walking on level ground and on decline surfaces of 5°,10°,and 15°.Methods:Twenty-five TKR patients and 10 healthy controls performed 5 walking trials on different decline slopes on a force platform and an instrumented ramp system.Two analyses of variance,2×2(limb×group)and 2×4(limb×decline slope),were used to examine selected biomechanics variables.Results:The replaced limb of TKR patients had lower peak loading-response and push-off knee extension moment than the non-replaced and the matched limb of healthy controls.No differences were found in loading-response and push-off knee internal abduction moments among replaced,non-replaced,and matched limb of healthy controls.The knee flexion range of motion,peak loading-response vertical ground reaction force,and peak knee extension moment increased across all slope comparisons between 0°and 15°in both the replaced and non-replaced limb of TKR patients.Conclusion:Downhill walking may not be appropriate to include in early stage rehabilitation exercise protocols for TKR patients.
文摘Background: Q-Factor(QF), or the inter-pedal width, in cycling is similar to step-width in gait. Although increased step-width has been shown to reduce peak knee abduction moment(KAbM), no studies have examined the biomechanical effects of increased QF in cycling at different workrates in healthy participants.Methods: A total of 16 healthy participants(8 males, 8 females, age: 22.4 ± 2.6 years, body mass index: 22.78 ± 1.43 kg/m^2, mean ± SD) participated.A motion capture system and customized instrumented pedals were used to collect 3-dimensional kinematic(240 Hz) and pedal reaction force(PRF)(1200 Hz) data in 12 testing conditions: 4 QF conditions—Q1(15.0 cm), Q2(19.2 cm), Q3(23.4 cm), and Q4(27.6 cm)—under 3 workrate conditions—80 watts(W), 120 W, and 160 W. A 3 × 4(QF × workrate) repeated measures of analysis of variance were performed to analyze differences among conditions(p < 0.05).Results: Increased QF increased peak KAbM by 47%, 56%, and 56% from Q1 to Q4 at each respective workrate. Mediolateral PRF increased from Q1 to Q4 at each respective workrate. Frontal-plane knee angle and range of motion decreased with increased QF. No changes were observed for peak vertical PRF, knee extension moment, sagittal plane peak knee joint angles, or range of motion.Conclusion: Increased QF increased peak KAbM, suggesting increased medial compartment loading of the knee. QF modulation may influence frontal-plane joint loading when using stationary cycling for exercise or rehabilitation purposes.
文摘目的探讨着鞋类型(裸足、普通鞋、极简鞋)与步行速度(快步走、常速行走)对膝关节生物力学指标的影响,为科学健身提供理论参考。方法采用Vicon三维运动捕捉系统、Kisler三维测力台同步采集10名男性在裸足、穿着不同鞋常速行走与快步走时下肢运动生物力学指标。采用双因素(2种行走方式×3种着鞋类型)重复测量方差分析对各指标进行统计分析。结果相对于快步走,常速行走时足底压力中心(center of pressure,COP)向外偏移较大,额状面膝关节力臂、膝关节内收外力矩和第1峰值负载率均较小,但额状面膝关节冲量矩较大;相对于穿着普通跑鞋,裸足或穿着极简鞋时,步幅变小,COP向外偏移较大,额状面膝关节力臂、膝关节内收外力矩、第1峰值负载率和额状面膝关节冲量矩较小。结论为降低额状面膝关节冲量矩以及峰值负载率,建议着极简鞋采用小步幅进行快步走锻炼。
