Hope Jasmine M, Zarkou Anastasia, Suri Cazmon, Field-Fote Edelle C
Division of Physical Therapy, School of Medicine, Emory University, Atlanta, GA 30322, USA.
Spinal Cord Injury Research Laboratory, Virginia C. Crawford Research Institute, Shepherd Center, Atlanta, GA 30309, USA.
Brain Sci. 2025 Apr 17;15(4):405. doi: 10.3390/brainsci15040405.
BACKGROUND/OBJECTIVES: After spinal cord injury (SCI), poor dorsiflexor control and involuntary plantar-flexor contraction impair walking. As whole-body vibration (WBV) improves voluntary muscle activation and modulates reflex excitability, it may improve ankle control. In this study, the dosage effects of WBV on walking speed, dorsiflexion, and spinal reflex excitability were examined.
Sixteen people with chronic motor-incomplete SCI participated in this randomized sham-control wash-in study. Two weeks of sham stimulation (wash-in phase) were followed by either 2 weeks of eight repetitions (short bout) or sixteen repetitions of WBV (long bout; intervention phase) per session. Walking speed, ankle angle at mid-swing, and low-frequency depression of the soleus H-reflex were measured before and after the wash-in phase and before and after the intervention phase.
A significant dosage effect of WBV was not observed on any of the measures of interest. There were no between-phase or within-phase differences in ankle angle during the swing phase or in low-frequency depression. When dosage groups were pooled together, there was a significant change in walking speed during the intervention phase (mean = 0.04 m/s, standard deviation = 0.06, = 0.02). There was not a significant correlation between overall change in walking speed and dorsiflexion angle or low-frequency depression during the study.
Whole-body vibration did not have a dosage-dependent effect on dorsiflexion during the swing phase or on spinal reflex excitability. Future studies assessing the role of corticospinal tract (CST) descending drive on increased dorsiflexor ability and walking speed are warranted.
背景/目的：脊髓损伤（SCI）后，背屈控制不佳和跖屈肌不自主收缩会影响行走。由于全身振动（WBV）可改善随意肌激活并调节反射兴奋性，因此可能改善踝关节控制。在本研究中，检测了WBV对步行速度、背屈和脊髓反射兴奋性的剂量效应。
16名慢性运动不完全性SCI患者参与了这项随机假对照导入研究。先进行两周的假刺激（导入期），然后每组分别接受为期两周的每次8次重复（短疗程）或16次重复的WBV（长疗程；干预期）。在导入期前后以及干预期前后测量步行速度、摆动中期的踝关节角度和比目鱼肌H反射的低频抑制。
未观察到WBV对任何感兴趣指标有显著的剂量效应。摆动期的踝关节角度或低频抑制在阶段间或阶段内均无差异。当将剂量组合并在一起时，干预期的步行速度有显著变化（平均值=0.04 m/s，标准差=0.06，P=0.02）。在研究期间，步行速度的总体变化与背屈角度或低频抑制之间无显著相关性。
全身振动对摆动期的背屈或脊髓反射兴奋性没有剂量依赖性影响。未来有必要开展研究，评估皮质脊髓束（CST）下行驱动对增加背屈能力和步行速度的作用。
