Department of Systems and Control Engineering, Tokyo Institute of Technology, Tokyo, Japan; Artificial Intelligence Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tokyo, Japan.
Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.
J Biomech. 2021 Jan 22;115:110201. doi: 10.1016/j.jbiomech.2020.110201. Epub 2020 Dec 24.
The ability to sustain steady straight-ahead walking is one goal of gait rehabilitation for individuals with unilateral above-knee (UAK) amputation. Despite the morphological and musculoskeletal asymmetry resulting from unilateral limb loss, the mediolateral ground-reaction-impulse (GRI) should be counterbalanced between the affected and unaffected limbs during straight-ahead walking. Therefore, we investigated the strategies of mediolateral ground-reaction-force (GRF) generation adopted by UAK prosthesis users walking along a straight path. GRFs of 15 participants with UAK amputation were measured during straight-ahead walking. Then, the mediolateral GRI, stance time, and mean mediolateral GRF during the stance phase of the affected and unaffected limbs were compared. To better understand the GRF generation strategy, statistical-parametric-mapping (SPM) was applied to assess the phase-dependent difference of the mediolateral GRFs between two limbs. The results showed that UAK prosthesis users can achieve symmetric mediolateral GRI during straight-ahead walking by adopting an asymmetric gait strategy: shorter stance time and higher mean mediolateral GRF over the stance phase for the affected than for the unaffected limb. In addition, the analysis using SPM revealed that the affected limb generates a higher mean medial GRF component than the unaffected limb, especially during the single-support phase. Thus, a higher medial GRF during the single-support phase of the affected limb may allow UAK prosthesis users to achieve mediolateral GRI that are similar to those of the unaffected limb. Further insights on these mechanics may serve as guidelines on the improved design of prosthetic devices and the rehabilitation needs of UAK prosthesis users.
维持稳定直线前进行走的能力是单侧膝上（UAK）截肢者步态康复的目标之一。尽管由于单侧肢体丧失导致形态和骨骼肌肉不对称，但在直线前进行走时，受影响和未受影响的肢体之间的横向地面反作用力脉冲（GRI）应该平衡。因此，我们研究了 UAK 假肢使用者在直线上行走时采用的横向地面反作用力（GRF）产生策略。在直线前进行走期间测量了 15 名 UAK 截肢参与者的 GRFs。然后，比较了受影响和未受影响肢体的横向 GRI、站立时间和站立阶段的平均横向 GRF。为了更好地理解 GRF 产生策略，应用统计参数映射（SPM）来评估两个肢体之间横向 GRF 的相位相关差异。结果表明，UAK 假肢使用者可以通过采用不对称步态策略在直线前进行走时实现对称的横向 GRI：受影响的肢体站立时间更短，站立阶段的平均横向 GRF 高于未受影响的肢体。此外，使用 SPM 的分析表明，受影响的肢体产生的平均内侧 GRF 分量高于未受影响的肢体，尤其是在单支撑阶段。因此，受影响肢体在单支撑阶段的较高内侧 GRF 可能使 UAK 假肢使用者能够实现类似于未受影响肢体的横向 GRI。对这些力学的进一步了解可以为假肢设计的改进和 UAK 假肢使用者的康复需求提供指导。
