Sato Sumire D, Choi Julia T
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States.
Neuroscience and Behavior Program, University of Massachusetts Amherst, Amherst, MA, United States.
Front Aging Neurosci. 2022 Aug 18;14:920475. doi: 10.3389/fnagi.2022.920475. eCollection 2022.
Healthy aging is associated with reduced corticospinal drive to leg muscles during walking. Older adults also exhibit slower or reduced gait adaptation compared to young adults. The objective of this study was to determine age-related changes in the contribution of corticospinal drive to ankle muscles during walking adaptation. Electromyography (EMG) from the tibialis anterior (TA), soleus (SOL), medial, and lateral gastrocnemius (MGAS, LGAS) were recorded from 20 healthy young adults and 19 healthy older adults while they adapted walking on a split-belt treadmill. We quantified EMG-EMG coherence in the beta-gamma (15-45 Hz) and alpha-band (8-15 Hz) frequencies. Young adults demonstrated higher coherence in both the beta-gamma band coherence and alpha band coherence, although effect sizes were greater in the beta-gamma frequency. The results showed that slow leg TA-TA coherence in the beta-gamma band was the strongest predictor of early adaptation in double support time. In contrast, early adaptation in step length symmetry was predicted by age group alone. These findings suggest an important role of corticospinal drive in adapting interlimb timing during walking in both young and older adults.
健康衰老与步行过程中皮质脊髓对腿部肌肉的驱动减少有关。与年轻人相比，老年人的步态适应性也较慢或降低。本研究的目的是确定在步行适应过程中，皮质脊髓驱动对踝关节肌肉贡献的年龄相关变化。在20名健康年轻人和19名健康老年人在分段带式跑步机上适应步行时，记录了胫骨前肌（TA）、比目鱼肌（SOL）、内侧和外侧腓肠肌（MGAS、LGAS）的肌电图（EMG）。我们量化了β-γ（15-45Hz）和α波段（8-15Hz）频率下的肌电图-肌电图相干性。年轻人在β-γ波段相干性和α波段相干性方面均表现出更高的相干性，尽管β-γ频率下的效应量更大。结果表明，β-γ波段中缓慢的腿部TA-TA相干性是双支撑期早期适应的最强预测指标。相比之下，步长对称性的早期适应仅由年龄组预测。这些发现表明，皮质脊髓驱动在年轻人和老年人步行过程中适应肢体间时间安排方面起着重要作用。
