Department of Kinesiology, Western Illinois University, Macomb, IL, USA.
Department of Rehabilitation Science, George Mason University, Fairfax, VA, USA.
Disabil Rehabil. 2022 Jan;44(1):52-58. doi: 10.1080/09638288.2020.1755729. Epub 2020 Apr 24.
To examine the effect of muscle fiber recruitment patterns on muscle oxygen utilization during treadmill walking in a group of individuals who have incomplete spinal cord injury.
5 participants with motor incomplete spinal cord injury (Age; 42.2 ± 18.8 years, Male; = 4) completed an over ground locomotor training program. Muscle utilization/oxygenation and activation of the medial gastrocnemius were measured by near infrared spectroscopy and surface electromyography pre- and post-over ground locomotor training during two separate treadmill walking bouts at self-selected speeds. Outcomes were changes in deoxygenation hemoglobin/myoglobin concentrations, and the change in median power of the power spectrum of the electromyography after training.
A significant increase in median power of the power spectrum of the electromyography signal was observed during both bouts of treadmill walking, 6-minute walking bout and longer fatiguing bout (49% = 0.047 and 48% = 0.035, respectively) post-over ground locomotor training. There was no significant change in muscle utilization/oxygenation post-over ground locomotor training. There was no significant effect of median power of the power spectrum on deoxygenation hemoglobin/myoglobin during either of the walking bouts.
The main finding of the current study was that median power of the power spectrum significantly increased following 12 weeks of over ground locomotor training, with no significant change in deoxygenation hemoglobin/myoglobin. The recruitment of more and/or larger motor units was seen in conjunction with no changes in muscle oxygen utilization for the same walking task.Implications for RehabilitationThe reduction of skeletal muscle innervation in Spinal Cord Injury may adversely affect the orderly recruitment of motor units, which could in turn blunt the oxidative metabolic response during physical activity.Over-ground locomotor could be a useful tool in the rehabilitative process following an incomplete spinal cord injury.
研究一组不完全性脊髓损伤患者在跑步机上行走时，肌纤维募集模式对肌肉氧利用的影响。
5 名运动功能不完全性脊髓损伤患者（年龄：42.2±18.8 岁，男性：=4）完成了一项地面步行训练计划。在两次独立的跑步机行走过程中，在自我选择的速度下，使用近红外光谱和表面肌电图分别在地面步行训练前后测量内侧腓肠肌的肌肉利用/氧合和激活情况。结果为训练后去氧血红蛋白/肌红蛋白浓度的变化，以及肌电图功率谱中值功率的变化。
在两次跑步机行走过程中，即 6 分钟行走回合和更长疲劳回合中，肌电图信号的中值功率谱均观察到显著增加（49%=0.047 和 48%=0.035，分别）。地面步行训练后肌肉利用/氧合无明显变化。中值功率谱对两种行走状态下的去氧血红蛋白/肌红蛋白均无显著影响。
本研究的主要发现是，在经过 12 周的地面步行训练后，中值功率谱显著增加，而去氧血红蛋白/肌红蛋白无明显变化。在相同的步行任务中，更多和/或更大的运动单位的募集与肌肉氧利用无明显变化同时出现。
脊髓损伤中骨骼肌肉神经支配的减少可能会对运动单位的有序募集产生不利影响，从而削弱体力活动期间的氧化代谢反应。地面步行训练可能是不完全性脊髓损伤康复过程中的有用工具。
