Effect of a soft exosuit on gait kinematics

Anti-gravity exosuits supporting hip and knee extension have emerged for overground training. This study investigated their effect on kinematics in individuals with incomplete spinal cord injury (iSCI) compared to regular walking and to walking with an overground BWS system. Fourteen individuals with iSCI were tested during overground walking in three conditions: regular, exosuit,
and BWS. Kinematics were assessed using the Xsens MVN motion capture system. Maximum hip extension was larger for exosuit compared to regular walking (Δ4.7°, 95% CI [1.4, 7.9]), but was not different compared to BWS. Mean knee flexion was smaller for exosuit compared to regular walking (Δ−1.7°, 95% CI [−3.0, −0.4]) and compared to BWS (Δ−3.5°, 95% CI [−5.4, −1.6]). Most secondary outcome measures (e.g. walking speed, stride length, step width, ML COM excursion) showed no differences between exosuit and regular walking. Comparing exosuit to BWS, most secondary outcome measures (e.g., walking speed, stride length, stride time, trunk inclination) favored BWS. An anti-gravity exosuit resulted in increased hip and knee extension, but did not translate into other gait improvements. Given the more favorable outcomes of the BWS system compared to the exosuit, exosuit design improvements are needed to be effectively implemented in gait rehabilitation after iSCI.

用于地面步行训练的抗重力外骨骼（anti-gravity exosuit），其核心功能为辅助髋膝伸展，目前已逐步投入应用。本研究针对不完全性脊髓损伤（incomplete spinal cord injury, iSCI）患者，对比了该类外骨骼与常规步行、佩戴地面式体重支持系统（Body Weight Support, BWS）步行时的运动学效应。
本研究纳入14名iSCI患者，让其在三种工况下完成地面步行测试：常规步行、佩戴外骨骼步行以及佩戴BWS步行。运动学数据采用Xsens MVN动作捕捉系统进行采集与分析。
与常规步行相比，佩戴外骨骼时的最大髋伸展角度更大（Δ4.7°，95%置信区间[1.4, 7.9]），但与BWS工况相比无显著差异。与常规步行相比，佩戴外骨骼时的平均膝关节屈曲角度更小（Δ−1.7°，95%置信区间[−3.0, −0.4]）；与BWS工况相比，该指标同样更小（Δ−3.5°，95%置信区间[−5.4, −1.6]）。
多数次要结局指标（如步行速度、步长、步宽、中外侧质心（medio-lateral center of mass, ML COM）偏移量）在佩戴外骨骼与常规步行之间无显著差异。对比佩戴外骨骼与BWS工况，多数次要结局指标（如步行速度、步长、步时、躯干倾斜角）均显示BWS系统更具优势。
抗重力外骨骼虽可提升髋膝伸展幅度，但未能带来其他步行功能的改善。鉴于BWS系统的结局表现优于外骨骼，未来需对外骨骼进行优化设计，方能将其有效应用于iSCI患者的步行康复训练中。