Shoulder and arm muscle activity during elastic band exercises performed in a hospital bed

Objective: Muscle atrophy is a common side-effect of bed rest during hospitalization. However, resistance training may minimize or even prevent these complications. Therefore, we evaluated the efficiency of four upper-body elastic resistance exercises that could be performed while lying or sitting in a hospital bed. Methods: Twenty-two healthy subjects performed three repetitions of each exercise in a supine and seated position with a perceived intensity of 3 (low) and 8 (high) on the Borg CR10 Scale. Surface electromyography was collected from 12 shoulder and arm muscles (e.g. trapezius, deltoideus, and biceps brachii), and normalized to a maximal voluntary isometric contraction (nEMG). Results: During all exercises performed at high intensity, moderate (>40%) to high (>60%) levels of nEMG were found for the majority of the analysed muscles, e.g. deltoideus (from 37% to 69%, median 57.5%), trapezius (from 43% to 66%, median 51%), and infraspinatus (from 54% to 66%, median 59%), with the exception of pectoralis major (from 29% to 47%, median 39.5%) and latissimus dorsi (from 15% to 22%, median 18.5%). No significant differences were found between the supine and seated positions for any of the exercises. Conclusion: This study showed that high levels of shoulder and arm muscle activity can be achieved while lying or sitting in a hospital bed using appropriate exercises with elastic bands. The data presented here can be used by physiotherapists as a guideline for selecting suitable and effective strengthening exercises during in-hospital rehabilitation to counteract bed-rest related muscle atrophy in the upper body.

研究目的：肌肉萎缩是住院期间卧床休息的常见并发症，而抗阻训练可减轻甚至预防此类并发症。为此，本研究评估了四种可在病床仰卧或坐位状态下实施的上肢弹性抗阻训练的有效性。
方法：22名健康受试者分别以仰卧位与坐位完成每项训练3次重复，自觉劳累强度采用伯格CR10自觉劳累分级量表（Borg CR10 Scale）评定为3（低强度）与8（高强度）。从12块肩臂肌肉（如斜方肌、三角肌、肱二头肌）采集表面肌电（surface electromyography）信号，并将其归一化至最大自主等长收缩值，得到归一化肌电（nEMG）。
结果：所有高强度训练中，多数受测肌肉的归一化肌电水平处于中等（>40%）至高等（>60%）区间，例如三角肌（37%~69%，中位数57.5%）、斜方肌（43%~66%，中位数51%）与冈下肌（54%~66%，中位数59%）；但胸大肌（29%~47%，中位数39.5%）和背阔肌（15%~22%，中位数18.5%）除外。所有训练在仰卧位与坐位间均未发现显著组间差异。
结论：本研究证实，通过弹力带开展适宜训练，可在病床仰卧或坐位状态下实现较高水平的肩臂肌肉激活。本研究数据可作为物理治疗师的临床参考指南，帮助其在住院康复阶段选择合适且有效的强化训练方案，以对抗卧床相关的上肢肌肉萎缩。