下肢外骨骼辅助的个体化预测性肌肉骨骼模拟：关节辅助策略的代谢与生物力学效应

中文摘要 AI 辅助

下肢外骨骼在降低行走能量消耗方面已取得显著进展。然而，设计最优辅助策略仍具挑战性，尤其是考虑到个体间在人体测量学和生物力学方面的差异。本研究利用肌肉骨骼模型的预测性模拟，探索能量最优的下肢关节辅助策略。基于六名健全受试者的个体化模型（采用基于BMI的肌肉力量缩放），在自选行走速度下进行预测性模拟以生成步态。模型中引入理想执行器，模拟峰值水平为25 Nm和50 Nm的各种关节辅助组合，以考察辅助对步态和代谢节省的影响。通过运输成本（COT）、关节运动学、肌肉激活、辅助力矩和关节级功率指标评估每种辅助配置的效果，以表征不同辅助策略的生物力学和能量影响。在50 Nm下，髋-膝-踝（H+K+A）联合辅助实现了最大的平均COT降低，为48.50%±4.55%，个体降低范围在42.22%至54.65%之间。在单关节条件中，辅助髋关节最为有效，COT降低31.77%±5.21%；膝关节和踝关节产生的降低较小且相当（分别为19.17%和17.02%）。髋-踝（H+A）辅助（44.60%±7.08%）成为最有效的双关节辅助配置。增加力矩上限主要增加了髋关节和踝关节的正向辅助功率，而膝关节辅助敏感性较低，并在预摆动阶段附近提供正向功率。这些结果支持H+A辅助作为高效的双执行器目标，同时将膝关节异常的预摆动功率策略确定为针对性实验验证的候选方案。

英文摘要

Lower-limb exoskeletons have made considerable progress in reducing energy expenditure during walking. However, designing optimal assistance strategies remains challenging, particularly given inter-individual variability in anthropometry and biomechanics. This study explores energy-optimal lower-limb joint-assistance strategies using predictive simulations with musculoskeletal models. Subject-specific models of six able-bodied subjects, with BMI-based muscle strength scaling, were used in predictive simulations to generate gait at self-selected walking speeds. Ideal actuators were incorporated to simulate various combinations of joint assistance at peak levels of 25 Nm and 50 Nm to examine the effects of assistance on gait and metabolic savings. The effects of each assistance configuration were assessed through cost of transport (COT), joint kinematics, muscle activations, assistive torques, and joint-level power metrics to characterize the biomechanical and energetic impacts of different assistance strategies. At 50 Nm, combined H+K+A (hip-knee-ankle) assistance resulted in the greatest mean COT reduction of 48.50 +/- 4.55%, with individual reductions ranging from 42.22% to 54.65% across the subjects. Among single-joint conditions, assisting the hip was most effective, reducing COT by 31.77 +/- 5.21%; the knee and ankle produced smaller, comparable reductions (19.17% and 17.02%). H+A (hip-ankle) assistance (44.60 +/- 7.08%) emerged as the most effective two-joint assistive configuration. Increasing the torque bound increased positive assistive power primarily at the hip and ankle, while knee assistance showed little sensitivity and delivered positive power near pre-swing. These results support H+A assistance as an efficient two-actuator target, while identifying the knee's atypical pre-swing power strategy as a candidate for targeted experimental validation.

发表机构

• University of Jaffna（贾夫纳大学）
• New Jersey Institute of Technology（新泽西理工学院）

机构由 AI 辅助整理，请以论文原文为准。