Professorship of Research Methodology and Data Analysis in Biomechanics, Institute of Human Movement Science and Health, Chemnitz University of Technology, Chemnitz, Germany.
Audi AG, Ingolstadt, Germany.
Work. 2022;72(4):1577-1591. doi: 10.3233/WOR-211272.
The Bioservo Ironhand® is a commercially available active hand exoskeleton for reducing grip-induced stress.
The study aimed at quantifying the effect of the Ironhand® exoskeleton on the myoelectric muscle activity of forearm flexor and extensor muscles in three relevant assembly grip tasks: 2-Finger-grip (2Finger), 5-Finger-grip (5Finger) and Full grip (FullGrip).
Twenty-two subjects were tested in three different exoskeleton conditions for each grip task (overall 3×3×10 = 90 repetitions in randomized order): Exoskeleton off (Off), Exoskeleton on, "locking tendency" 0% (On_LT0), and Exoskeleton on, "locking tendency" 85% (On_LT85). Muscle activity was measured at 25% of the participant's maximum grip force using two EMG sensors at the M. flexor digitorum superficialis (M.FDS) and one at the M. extensor digitorum (M.ED).
The effect of the Ironhand® exoskeleton varied depending on the grip task and the participant's sex. A statistically significant reduction in muscle activity of the M.FDS was found only for male subjects in the FullGrip condition. No reduction of muscular activity in the M.FDS was found for the other grip tasks (2Finger, 5Finger). For the females in the 2Finger condition, mean muscle activity of M.FDS even increased significantly in On_LT0 compared to Off. Besides differences between grip tasks and sex, the current study revealed substantial individual differences.
In addition to testing for statistical significance, a detailed exploratory analysis of exoskeleton effects at subject level should be performed to evaluate these from a safety and regulatory perspective.
Bioservo Ironhand® 是一种商用主动手部外骨骼，可减少握力引起的手部压力。
本研究旨在量化 Ironhand® 外骨骼对手臂屈肌和伸肌的前臂肌电活动的影响，涉及三种相关的装配握力任务：两指握力（2Finger）、五指握力（5Finger）和全握力（FullGrip）。
22 名受试者在三种不同的外骨骼条件下进行了每种握力任务的测试（总共在随机顺序下进行了 3×3×10=90 次重复）：外骨骼关闭（Off）、外骨骼开启、“锁定倾向”为 0%（On_LT0）和外骨骼开启、“锁定倾向”为 85%（On_LT85）。使用两个位于 M. flexor digitorum superficialis（M.FDS）和一个位于 M. extensor digitorum（M.ED）的肌电传感器，在参与者最大握力的 25%处测量肌肉活动。
Ironhand®外骨骼的效果因握力任务和参与者的性别而异。仅在全握力条件下，男性受试者的 M.FDS 肌肉活动明显减少。对于其他握力任务（2Finger、5Finger），未发现 M.FDS 肌肉活动减少。对于 2Finger 条件下的女性，与 Off 相比，M.FDS 的平均肌肉活动甚至在 On_LT0 时显著增加。除了握力任务和性别之间的差异外，本研究还发现了个体之间的显著差异。
除了测试统计学意义外，还应从安全和监管角度对外骨骼在个体水平上的效果进行详细的探索性分析，以进行评估。
