1 Department of Physical Medicine and Rehabilitation, School of Medicine, Indiana University, Indianapolis, Indiana.
2 Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, Illinois.
J Neurotrauma. 2019 Jun 15;36(12):2036-2044. doi: 10.1089/neu.2018.5900. Epub 2019 Feb 1.
Recent data demonstrate improved locomotion with high-intensity locomotor training (LT) in individuals with incomplete spinal cord injury (iSCI), although concerns remain regarding reinforcement of abnormal motor strategies. The present study evaluated the effects of LT intensity on kinematic and neuromuscular coordination in individuals with iSCI. Using a randomized, crossover design, participants with iSCI received up to 20 sessions of high-intensity LT, with attempts to achieve 70-85% of age-predicted maximum heart rate (HRmax), or low-intensity LT (50-65% HRmax), following which the other intervention was performed. Specific measures included spatiotemporal variables, sagittal-plane gait kinematics, and neuromuscular synergies from electromyographic (EMG) recordings. Correlation analyses were conducted to evaluate associations between variables. Significant improvements in sagittal-plane joint excursions and intralimb hip-knee coordination were observed following high- but not low-intensity LT when comparing peak treadmill (TM) speed before and after LT. Neuromuscular complexity (i.e., number of synergies to explain >90% of EMG variance) was also increased following high- but not low-intensity LT. Comparison of speed-matched trials confirmed significant improvements in the knee excursion of the less impaired limb and intralimb hip-knee coordination, as well as improvements in neuromuscular complexity following high-intensity LT. These findings suggest greater neuromuscular complexity may be due to LT and not necessarily differences in speeds. Only selected kinematic changes (i.e., weak hip excursion) was correlated to improvements in treadmill speed. In conclusion, LT intensity can facilitate gains in kinematic variables and neuromuscular synergies in individuals with iSCI.
最近的数据表明，高强度运动训练（LT）可以改善不完全性脊髓损伤（iSCI）患者的运动功能，尽管人们仍然对强化异常运动策略存在担忧。本研究评估了 LT 强度对 iSCI 患者运动学和神经肌肉协调性的影响。采用随机交叉设计，iSCI 患者接受多达 20 次高强度 LT 或低强度 LT（50-65% HRmax），每次尝试达到 70-85%的年龄预测最大心率（HRmax），之后进行另一种干预。具体措施包括时空变量、矢状面步态运动学和肌电图（EMG）记录的神经肌肉协同作用。进行相关分析以评估变量之间的关联。与低强度 LT 相比，高强度 LT 后，峰值跑步机（TM）速度前后比较时，矢状面关节运动和肢体间髋关节-膝关节协调性显著改善。神经肌肉复杂性（即，解释>90%的 EMG 方差的协同作用数）也随着高强度 LT 而增加。速度匹配试验的比较证实，在高但不是低强度 LT 后，非受损肢体的膝关节运动和肢体间髋关节-膝关节协调性显著改善，神经肌肉复杂性也得到改善。这些发现表明，神经肌肉复杂性的增加可能是由于 LT，而不一定是速度的差异。只有选定的运动学变化（即，弱髋关节运动）与 TM 速度的改善相关。总之，LT 强度可以促进 iSCI 患者运动学变量和神经肌肉协同作用的改善。
