Abstract

Constraining knee flexion of non-disabled individuals could further our understanding regarding the importance of knee joint during gait, which is a common disturbance in individuals with gait impairment. In this study we investigated whether a mechanical constraint of knee flexion in non-disabled adults would lead to compensatory strategies. Eleven non-disabled male adults walked without and with an orthosis that permitted full extension and limited knee flexion up to either 45° or 30°. We analyzed the temporal organization of lower limb kinematics and electromyograms of the rectus femoris, vastus medialis and lateralis, tibialis anterior, semitendinosus, biceps femoris, and gastrocnemius medialis and lateralis. Non-disabled adults compensated for the reduced knee flexion by increasing hip and ankle joint excursions and ankle flexor activation amplitude. Also, these adults shortened pre-swing and lengthened swing duration in the constrained limb and increased the activity of bifunctional hip extensor and knee flexor muscles in the constrained limb in relation to the unconstrained limb. The use of an orthosis that limited knee flexion in non-disabled adults leaded to compensatory strategies in the temporal organization of joint excursions and muscle activations in the constrained limb. The compensatory effects were correlated with the extent of knee flexion constraint.

 抽象的

限制非残疾个体的膝关节弯曲可以进一步加深我们对膝关节在步态中的重要性的理解，这是步态障碍个体中常见的障碍。在这项研究中，我们调查了非残疾成年人膝关节屈曲的机械约束是否会导致补偿策略。 11 名非残疾男性成年人在不使用或使用矫形器的情况下行走，该矫形器允许完全伸展并将膝盖弯曲限制为 45° 或 30°。我们分析了股直肌、股内侧肌和外侧肌、胫骨前肌、半腱肌、股二头肌、腓肠肌内侧肌和外侧肌的下肢运动学和肌电图的时间组织。非残疾成年人通过增加髋关节和踝关节的偏移以及踝屈肌的激活幅度来补偿膝关节屈曲的减少。此外，与不受约束的肢体相比，这些成年人缩短了受约束肢体的预摆动和延长了摆动持续时间，并增加了受约束肢体中双功能髋伸肌和膝屈肌的活动。在非残疾成年人中使用限制膝关节弯曲的矫形器导致了受约束肢体的关节偏移和肌肉激活的时间组织的补偿策略。代偿效应与膝关节屈曲受限程度相关。