Abstract：
BACKGROUND: Transfemoral prosthesis users\' high fall rate is related to increased injury risk, medical costs, and fear of falling. Better understanding how stumble conditions (e.g., participant age, prosthesis type, side tripped, and swing phase of perturbation) affect transfemoral prosthesis users could provide insight into response deficiencies and inform fall prevention interventions.
METHODS: Six unilateral transfemoral prosthesis users experienced obstacle perturbations to their sound limb in early, mid, and late swing phase. Fall outcome, recovery strategy, and kinematics of each response were recorded to characterize (1) recoveries versus falls for transfemoral prosthesis users and (2) prosthesis user recoveries versus healthy adult recoveries.
RESULTS: Out of 26 stumbles, 15 resulted in falls with five of six transfemoral prosthesis users falling at least once. By contrast, in a previously published study of seven healthy adults comprising 214 stumbles using the same experimental apparatus, no participants fell. The two oldest prosthesis users fell after every stumble, stumbles in mid swing resulted in the most falls, and prosthesis type was not related to strategy/fall outcomes. Prosthesis users who recovered used the elevating strategy in early swing, lowering strategy in late swing, and elevating or lowering/delayed lowering with hopping in mid swing, but exhibited increased contralateral (prosthetic-side) thigh abduction and trunk flexion relative to healthy controls. Falls occurred if the tripped (sound) limb did not reach ample thigh/knee flexion to sufficiently clear the obstacle in the elevating step, or if the prosthetic limb did not facilitate a successful step response after the initial sound-side elevating or lowering step. Such responses generally led to smaller step lengths, less anterior foot positioning, and more forward trunk flexion/flexion velocity in the resulting foot-strikes.
CONCLUSIONS: Introducing training (e.g., muscle strength or task-specific motor skill) and/or modifying assistive devices (e.g., lower-limb prostheses or exoskeletons) may improve responses for transfemoral prosthesis users. Specifically, training or exoskeleton assistance could help facilitate sufficient thigh/knee flexion for elevating; training or prosthesis assistance could provide support-limb counteracting torques to aid in elevating; and training or prosthesis assistance could help initiate and safely complete prosthetic swing.
METHODS: Six unilateral transfemoral prosthesis users experienced obstacle perturbations to their sound limb in early, mid, and late swing phase. Fall outcome, recovery strategy, and kinematics of each response were recorded to characterize (1) recoveries versus falls for transfemoral prosthesis users and (2) prosthesis user recoveries versus healthy adult recoveries.
RESULTS: Out of 26 stumbles, 15 resulted in falls with five of six transfemoral prosthesis users falling at least once. By contrast, in a previously published study of seven healthy adults comprising 214 stumbles using the same experimental apparatus, no participants fell. The two oldest prosthesis users fell after every stumble, stumbles in mid swing resulted in the most falls, and prosthesis type was not related to strategy/fall outcomes. Prosthesis users who recovered used the elevating strategy in early swing, lowering strategy in late swing, and elevating or lowering/delayed lowering with hopping in mid swing, but exhibited increased contralateral (prosthetic-side) thigh abduction and trunk flexion relative to healthy controls. Falls occurred if the tripped (sound) limb did not reach ample thigh/knee flexion to sufficiently clear the obstacle in the elevating step, or if the prosthetic limb did not facilitate a successful step response after the initial sound-side elevating or lowering step. Such responses generally led to smaller step lengths, less anterior foot positioning, and more forward trunk flexion/flexion velocity in the resulting foot-strikes.
CONCLUSIONS: Introducing training (e.g., muscle strength or task-specific motor skill) and/or modifying assistive devices (e.g., lower-limb prostheses or exoskeletons) may improve responses for transfemoral prosthesis users. Specifically, training or exoskeleton assistance could help facilitate sufficient thigh/knee flexion for elevating; training or prosthesis assistance could provide support-limb counteracting torques to aid in elevating; and training or prosthesis assistance could help initiate and safely complete prosthetic swing.
摘要：
背景：经股假体使用者的高跌倒率与受伤风险增加有关，医疗费用,害怕跌倒。更好地了解如何绊倒条件(例如，参与者年龄,假体类型,侧面跳闸,和扰动的摆动阶段）影响经股假体使用者可以提供对反应缺陷的洞察力，并告知跌倒预防干预措施。
方法：六个单侧经股假体使用者在早期经历了对其健全肢体的障碍扰动，mid,和后期摆动阶段。秋天的结果，恢复战略，记录每个反应的运动学，以表征（1）经股假体使用者的恢复与跌倒，以及（2）假体使用者的恢复与健康成人恢复。
结果：在26次失误中，15导致跌倒，六名经股假体使用者中有五名至少跌倒一次。相比之下,在先前发表的一项对7名健康成年人的研究中，包括使用相同的实验装置的214个绊脚石，没有参与者倒下。两个年龄最大的假肢使用者每次跌倒后都摔倒了，在中挥杆时跌跌撞撞导致了最多的跌倒，假体类型与策略/跌倒结局无关.康复的假肢用户在早期使用了提升策略，后期波动降低策略，和升高或降低/延迟降低跳跃在中间摆动，但与健康对照组相比，对侧（假体侧）大腿外展和躯干屈曲增加。如果绊倒的(声音)肢体没有达到足够的大腿/膝盖屈曲以充分清除提升步骤中的障碍物,则会发生跌倒。或者假肢在最初的声音侧升高或降低步骤后没有促进成功的步骤响应。这样的反应通常导致较小的步长，较少前足定位，和更多的向前躯干屈曲/屈曲速度在所产生的脚。
结论：介绍培训(例如，肌肉力量或特定任务的运动技能)和/或修改辅助设备(例如，下肢假体或外骨骼）可以改善经股假体使用者的反应。具体来说,训练或外骨骼辅助可以帮助促进足够的大腿/膝盖屈曲以进行提升;训练或假肢辅助可以提供支撑肢体抵消扭矩以帮助提升;并且训练或假肢辅助可以帮助启动和安全地完成假肢摆动。
方法：六个单侧经股假体使用者在早期经历了对其健全肢体的障碍扰动，mid,和后期摆动阶段。秋天的结果，恢复战略，记录每个反应的运动学，以表征（1）经股假体使用者的恢复与跌倒，以及（2）假体使用者的恢复与健康成人恢复。
结果：在26次失误中，15导致跌倒，六名经股假体使用者中有五名至少跌倒一次。相比之下,在先前发表的一项对7名健康成年人的研究中，包括使用相同的实验装置的214个绊脚石，没有参与者倒下。两个年龄最大的假肢使用者每次跌倒后都摔倒了，在中挥杆时跌跌撞撞导致了最多的跌倒，假体类型与策略/跌倒结局无关.康复的假肢用户在早期使用了提升策略，后期波动降低策略，和升高或降低/延迟降低跳跃在中间摆动，但与健康对照组相比，对侧（假体侧）大腿外展和躯干屈曲增加。如果绊倒的(声音)肢体没有达到足够的大腿/膝盖屈曲以充分清除提升步骤中的障碍物,则会发生跌倒。或者假肢在最初的声音侧升高或降低步骤后没有促进成功的步骤响应。这样的反应通常导致较小的步长，较少前足定位，和更多的向前躯干屈曲/屈曲速度在所产生的脚。
结论：介绍培训(例如，肌肉力量或特定任务的运动技能)和/或修改辅助设备(例如，下肢假体或外骨骼）可以改善经股假体使用者的反应。具体来说,训练或外骨骼辅助可以帮助促进足够的大腿/膝盖屈曲以进行提升;训练或假肢辅助可以提供支撑肢体抵消扭矩以帮助提升;并且训练或假肢辅助可以帮助启动和安全地完成假肢摆动。
