Department of Veterans Affairs, RR&D Center, Seattle, WA, USA.
Gait Posture. 2011 Oct;34(4):502-7. doi: 10.1016/j.gaitpost.2011.07.001. Epub 2011 Jul 30.
Lower extremity amputation not only limits mobility, but also increases the risk of knee osteoarthritis of the intact limb. Dynamic walking models of non-amputees suggest that pushing-off from the trailing limb can reduce collision forces on the leading limb. These collision forces may determine the peak knee external adduction moment (EAM), which has been linked to the development of knee OA in the general population. We therefore hypothesized that greater prosthetic push-off would lead to reduced loading and knee EAM of the intact limb in unilateral transtibial amputees. Seven unilateral transtibial amputees were studied during gait under three prosthetic foot conditions that were intended to vary push-off. Prosthetic foot-ankle push-off work, intact limb knee EAM and ground reaction impulses for both limbs during step-to-step transition were measured. Overall, trailing limb prosthetic push-off work was negatively correlated with leading intact limb 1st peak knee EAM (slope=-.72±.22; p=.011). Prosthetic push-off work and 1st peak intact knee EAM varied significantly with foot type. The prosthetic foot condition with the least push-off demonstrated the largest knee EAM, which was reduced by 26% with the prosthetic foot producing the most push-off. Trailing prosthetic limb push-off impulse was negatively correlated with leading intact limb loading impulse (slope=-.34±.14; p=.001), which may help explain how prosthetic limb push-off can affect intact limb loading. Prosthetic feet that perform more prosthetic push-off appear to be associated with a reduction in 1st peak intact knee EAM, and their use could potentially reduce the risk and burden of knee osteoarthritis in this population.
下肢截肢不仅限制了活动能力，还增加了未截肢肢体患膝骨关节炎的风险。非截肢者的动态行走模型表明，从跟随腿发力可以减少对主导腿的碰撞力。这些碰撞力可能决定了膝关节外展矩的峰值（EAM），而膝关节外展矩的峰值与一般人群中膝骨关节炎的发展有关。因此，我们假设在单侧胫骨截肢者中，更大的假肢蹬离会导致未截肢肢体的负荷和膝关节 EAM 降低。在三种旨在改变蹬离的假肢脚条件下，对 7 名单侧胫骨截肢者进行了步态研究。测量了假肢脚-脚踝蹬离功、未截肢侧膝关节 EAM 和两肢在步间过渡期间的地面反作用力脉冲。总体而言，跟随腿假肢蹬离功与主导未截肢侧膝关节 EAM 的 1 峰值呈负相关（斜率=-.72±.22；p=.011）。假肢蹬离功和 1 峰值未截肢侧膝关节 EAM 随脚型显著变化。蹬离功最小的假肢脚表现出最大的膝关节 EAM，而蹬离功最大的假肢脚使膝关节 EAM 降低了 26%。跟随腿假肢蹬离脉冲与主导未截肢侧加载脉冲呈负相关（斜率=-.34±.14；p=.001），这可能有助于解释假肢腿蹬离如何影响未截肢腿的加载。表现出更多假肢蹬离的假肢脚似乎与 1 峰值未截肢侧膝关节 EAM 的降低有关，它们的使用可能会降低该人群中膝骨关节炎的风险和负担。
