School of Kinesiology, University of Michigan, Ann Arbor, MI 48109, USA.
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
J Biomech. 2021 Jun 9;122:110438. doi: 10.1016/j.jbiomech.2021.110438. Epub 2021 Apr 20.
The ability to maintain balance when turning is essential to functional and independent living. Due to the lack of neuromuscular ankle control on the prosthetic side in people with a transtibial amputation (TTA), turning is likely more challenging. The purpose of this study was to quantify how people with TTA maintain dynamic balance during 90-degree turns made with the prosthesis on the inside and outside of the turn compared to people without amputation. Eight participants with TTA and eight age-, height-, and sex- matched non-amputee controls performed left and right 90-degree step turns at a self-selected speed. The primary outcomes were range of whole-body angular momentum and positive and negative contributions of six segment groups (head/trunk, pelvis, arms, and legs) to whole-body angular momentum during the continuation stride. Participants with TTA had greater range of frontal- and sagittal-plane whole-body angular momentum when turning with the prosthesis on the inside compared controls. They also had a greater range of whole-body angular momentum in all planes of motion when turning with the prosthesis on the inside compared to outside of the turn. The contributions for the head/trunk and inside and outside legs differed between groups and turns, suggesting altered interactions between segment momenta to compensate for the reduced contribution of the amputated leg. This study provides insight into possible training paradigms to reduce the high incidence of turn related falls in people with TTA and, potentially, ways to alter prosthetic function to promote balance control.
当转身时，保持平衡的能力对于功能独立的生活至关重要。由于在胫骨截肢（TTA）患者的假肢侧缺乏神经肌肉控制，因此转身可能更具挑战性。本研究的目的是定量分析 TTA 患者在使用假肢进行内、外侧 90 度转身时如何保持动态平衡，与未截肢者相比。8 名 TTA 患者和 8 名年龄、身高和性别匹配的非截肢对照组患者以自选择的速度进行左右 90 度步向转身。主要结果是在继续步幅期间，整个身体角动量的范围以及六个节段组（头部/躯干、骨盆、手臂和腿部）对整个身体角动量的正、负贡献。当使用假肢进行内侧转身时，TTA 患者的额状面和矢状面整个身体角动量范围大于对照组。与外侧转身相比，他们在所有运动平面的整个身体角动量范围也更大。在组间和转弯时，头部/躯干和内外腿的贡献不同，这表明为了补偿截肢腿的贡献减少，节段动量之间的相互作用发生了改变。这项研究为减少 TTA 患者转弯相关跌倒的高发生率提供了深入了解，并且可能为改变假肢功能以促进平衡控制提供了方法。
