Deltoid RMS EMG percentiles.

ObjectiveThe goal of this study was to compare erector spinae muscle fatigue, upper limb muscle activity, body areas discomfort, and heart rate during a 10-min carrying task with and without a passive upper-body exoskeleton (CarrySuitⓇ) while considering sex influences.BackgroundPassive exoskeletons are commercially available to assist lifting or carrying task. However, evidence of their impact on muscle activity, fatigue, heart rate and discomfort are scarce and/or do not concur during carrying tasks.MethodThirty participants (16 females and 14 male) performed a 10-min, 15kg load-carrying task with and without the exoskeleton in two non-consecutive days. Heart rate, and erector spinae, deltoid, biceps and brachioradialis muscle activity were recorded during the carrying tasks. In addition, erector spinae electromyography during an isometric hold test and discomfort ratings were measured before and after the task.ResultsWhile without the exoskeleton upper limb muscle activity increased or remained constant during the carrying task and showing high peak activation for both males and females, a significant activity reduction was observed with the exoskeleton. Low back peak activation, heart rate and discomfort were lower with than without the exoskeleton. In males muscle activation was significantly asymmetric without the exoskeleton and more symmetric with the exoskeleton.ConclusionThe tested passive exoskeleton appears to alleviate the physical workload and impact of carrying heavy loads on the upper limbs and lower back for both males and females.研究目的：本研究旨在对比佩戴与不佩戴被动上身外骨骼（CarrySuit®）的10分钟负重任务中，受试者的竖脊肌（erector spinae）疲劳程度、上肢肌肉活动、身体区域不适度及心率水平，并考量性别因素带来的影响。 研究背景：目前市场上已有商用被动外骨骼用于辅助抬举或负重作业，但现有关于其在负重任务中对肌肉活动、肌肉疲劳、心率及身体不适度影响的研究证据较为匮乏，且相关研究结论尚未达成统一。 研究方法：30名受试者（16名女性、14名男性）分别在两个非连续日期完成佩戴与不佩戴外骨骼的10分钟、15kg负重任务。任务过程中，同步记录受试者的心率，以及竖脊肌、三角肌（deltoid）、肱二头肌（biceps）和肱桡肌（brachioradialis）的肌肉活动信号。此外，在任务前后分别测量等长收缩测试中的肌电（electromyography）信号，并采集受试者的身体不适度评分。 研究结果：未佩戴外骨骼时，受试者的上肢肌肉活动在负重任务中呈上升或维持不变的趋势，且男女受试者均出现较高的峰值激活水平；而佩戴外骨骼后，上肢肌肉活动显著降低。与未佩戴外骨骼的情况相比，佩戴外骨骼时受试者的下背部峰值激活程度、心率及身体不适度均更低。此外，男性受试者在未佩戴外骨骼时肌肉激活显著不对称，佩戴外骨骼后肌肉激活对称性明显提升。 研究结论：本次测试的被动上身外骨骼可有效减轻男女受试者负重重物时的身体负荷，缓解负重对上肢与下背部造成的不良影响。