Acute effects of locomotor training on overground walking speed and H-reflex modulation in individuals with incomplete spinal cord injury.

OBJECTIVE: The purpose of this study was to assess the effect of a single bout of a locomotor-training paradigm on overground walking speed and H-reflex modulation of individuals with incomplete spinal cord injury (SCI).

METHODS: Self-selected and maximum walking speeds and soleus H-reflexes (H/M ratios) during standing and stance and swing phases of walking (self-selected velocity) were obtained from 4 individuals with American Spinal Injury Association impairment classification D. Data were collected immediately before and after a single bout of locomotor training with body weight support on a treadmill. The pretraining H/M ratios of the SCI subjects were also compared with values from 4 able-bodied subjects who did not receive the intervention. Maximum H/M ratios while standing and during midstance and midswing phases of overground walking were considerably greater in the SCI subjects than in the control subjects.

RESULTS: After the single bout of training, self-selected and maximum overground walking speeds of the subjects with SCI increased by 26% and 25%, respectively. Furthermore, H-reflexes were significantly more depressed in the SCI subjects during overground walking (28% less during stance, 34% less during swing).

CONCLUSIONS: Although preliminary, these findings indicate that a single bout of locomotor training produced immediate increases in walking velocity and acute neurophysiologic changes in individuals with incomplete SCI.