Mulroy S J, Gronley J K, Newsam C J, Perry J
Rancho Los Amigos Medical Center, Pathokinesiology Laboratory, Downey, CA 90242, USA.
Arch Phys Med Rehabil. 1996 Feb;77(2):187-93. doi: 10.1016/s0003-9993(96)90166-5.
Phasing and intensity of shoulder muscle activity during wheelchair propulsion were documented to identify muscles at risk for fatigue and overuse.
Electromyographic (EMG) activity of 12 muscles was recorded with wire electrodes in 17 paraplegic men during propulsion on a stationary ergometer.
Push and recovery phases of the propulsion cycle were determined with an instrumented pushrim. Onset and cessation of EMG were compared between muscles with a repeated measures ANOVA. Average and peak EMG intensity also were identified.
All muscles functioned either in push or recovery phases, except supraspinatus, which displayed both patterns, and latissimus dorsi, which was inconsistent. The 6 push phase muscles--anterior deltoid, sternal pectoralis major, supraspinatus, infraspinatus, serratus anterior, and long head of biceps brachii--had onsets in late recovery (78% to 93% cycle) with peak EMG in the first 10% of the cycle. Pectoralis major and supraspinatus had the highest peak (58% and 67%MAX) and average (35% and 27%MAX) EMG intensities in this group. Cessation occurred in late push (17% to 23% cycle) except in biceps brachii (8% cycle) (p < .01). The 5 recovery muscles--middle and posterior deltoid, subscapularis, supraspinatus, and middle trapezius--had EMG onsets in late push (17% to 26% cycle) with moderate average intensities (21% to 32%MAX). These muscles had two EMG peaks (end of push and mid-recovery). Cessation was in late recovery (82% to 91% cycle).
Muscles most vulnerable for fatigue were pectoralis major, supraspinatus, and recovery muscles. Endurance training was recommended.
记录轮椅推进过程中肩部肌肉活动的阶段和强度，以确定有疲劳和过度使用风险的肌肉。
在17名截瘫男性使用固定测力计推进轮椅时，用线电极记录12块肌肉的肌电图（EMG）活动。
使用装有传感器的轮圈确定推进周期的推和恢复阶段。采用重复测量方差分析比较各肌肉之间肌电图的起始和停止情况。还确定了肌电图的平均强度和峰值强度。
除了显示两种模式的冈上肌和表现不一致的背阔肌外，所有肌肉均在推或恢复阶段发挥作用。6块推阶段肌肉——三角肌前束、胸大肌胸骨部、冈上肌、冈下肌、前锯肌和肱二头肌长头——在恢复后期（周期的78%至93%）开始活动，肌电图峰值出现在周期的前10%。该组中胸大肌和冈上肌的肌电图峰值（分别为最大值的58%和67%）和平均强度（分别为最大值的35%和27%）最高。除肱二头肌（周期的8%）外，其他肌肉在推后期（周期的17%至23%）停止活动（p < .01）。5块恢复阶段肌肉——三角肌中束和后束、肩胛下肌、冈上肌和斜方肌中束——在推后期（周期的17%至26%）开始出现肌电图活动，平均强度适中（最大值的21%至32%）。这些肌肉有两个肌电图峰值（推结束时和恢复中期）。停止活动发生在恢复后期（周期的82%至91%）。
最易疲劳的肌肉是胸大肌、冈上肌和恢复阶段的肌肉。建议进行耐力训练。
