Department of Biomedical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia.
Clinical Exercise and Rehabilitation Unit, Discipline of Exercise and Sports Sciences, Faculty of Health Sciences, University of Sydney, Lidcombe, NSW 2141, Australia.
Sensors (Basel). 2017 Jul 14;17(7):1627. doi: 10.3390/s17071627.
A mechanomyography muscle contraction (MC) sensor, affixed to the skin surface, was used to quantify muscle tension during repetitive functional electrical stimulation (FES)-evoked isometric rectus femoris contractions to fatigue in individuals with spinal cord injury (SCI). Nine persons with motor complete SCI were seated on a commercial muscle dynamometer that quantified peak torque and average torque outputs, while measurements from the MC sensor were simultaneously recorded. MC-sensor-predicted measures of dynamometer torques, including the signal peak (SP) and signal average (SA), were highly associated with isometric knee extension peak torque (SP: r = 0.91, < 0.0001), and average torque (SA: r = 0.89, < 0.0001), respectively. Bland-Altman (BA) analyses with Lin's concordance () revealed good association between MC-sensor-predicted peak muscle torques (SP; = 0.91) and average muscle torques (SA; = 0.89) with the equivalent dynamometer measures, over a range of FES current amplitudes. The relationship of dynamometer torques and predicted MC torques during repetitive FES-evoked muscle contraction to fatigue were moderately associated (SP: r = 0.80, < 0.0001; SA: r = 0.77; < 0.0001), with BA associations between the two devices fair-moderate (SP; = 0.70: SA; = 0.30). These findings demonstrated that a skin-surface muscle mechanomyography sensor was an accurate proxy for electrically-evoked muscle contraction torques when directly measured during isometric dynamometry in individuals with SCI. The novel application of the MC sensor during FES-evoked muscle contractions suggested its possible application for real-world tasks (e.g., prolonged sit-to-stand, stepping,) where muscle forces during fatiguing activities cannot be directly measured.
一种肌动描记术（MMG）肌肉收缩传感器贴在皮肤表面，用于量化脊髓损伤（SCI）患者在重复功能性电刺激（FES）引起的等长股直肌收缩至疲劳过程中的肌肉张力。9 名运动完全性 SCI 患者坐在商业肌肉测力计上，该测力计量化峰值扭矩和平均扭矩输出，同时同时记录 MMG 传感器的测量结果。MMG 传感器预测的测力计扭矩测量值，包括信号峰值（SP）和信号平均值（SA），与等长膝关节伸展峰值扭矩（SP：r = 0.91，<0.0001）和平均扭矩（SA：r = 0.89，<0.0001）高度相关。Bland-Altman（BA）分析与 Lin 的一致性（）显示，在 FES 电流幅度范围内，MMG 传感器预测的峰值肌肉扭矩（SP；= 0.91）和平均肌肉扭矩（SA；= 0.89）与等效测力计测量值之间存在良好的关联。在重复性 FES 诱发肌肉收缩至疲劳过程中，测力计扭矩与预测的 MMG 扭矩之间的关系中度相关（SP：r = 0.80，<0.0001；SA：r = 0.77；<0.0001），两种设备之间的 BA 关联中等适度（SP；= 0.70：SA；= 0.30）。这些发现表明，当在 SCI 患者的等速测力过程中直接测量时，皮肤表面肌动描记术传感器是电诱发肌肉收缩扭矩的准确替代物。MMG 传感器在 FES 诱发的肌肉收缩中的新应用表明，它可能适用于现实世界的任务（例如，长时间的坐站、踏步），在这些任务中，疲劳活动期间的肌肉力量无法直接测量。
