Abstract: Purpose: Sparse data exist about effects of locomotor training on spasticity in individuals with spinal cord injury (SCI). We investigated changes in spastic responses in individuals with motor-incomplete SCI (MISCI) associated with locomotor training and examined properties of a biomechanical measure of clonus severity, plantar flexor reflex threshold angle (PF RTA). Methods: In 18 individuals with chronic MISCI, we assessed biomechanical and electrophysiologic measures of extensor spasticity and their relationship with walking speed before and after 12 weeks of body-weight supported locomotor training. Measures included PF RTA, plantar flexor (ankle clonus) and quadriceps spasm duration, soleus H-reflex, and ankle muscle…electromyography. PF RTA validity was assessed by measuring PF RTA and clonus duration in 40 individuals with SCI and 10 non-disabled individuals. Results: Locomotor training was associated with decreased PF RTA (p = 0.06), ankle clonus (p = 0.09) and quadriceps spasm (p = 0.05). PF RTA discriminated between non-disabled individuals and individuals with SCI and was moderately correlated with walking speed, soleus H/M ratio, and quadriceps spasm duration. Conclusions: In persons with spastic paresis due to MISCI, locomotor training was associated with decreased spasticity as measured by decreased plantar flexor excitability, ankle clonus, and quadriceps spasm.
Show more
Abstract: Purpose: Individuals with spinal cord injury (SCI) often have involuntary, reflex-evoked muscle activity resulting in spasticity. Vibration may modulate reflex activity thereby decreasing spasticity. This study suggests feasibility of using whole-body vibration (WBV) to decrease quadriceps spasticity in individuals with SCI. Methods: Participants were individuals (n=16) with spastic quadriceps hypertonia due to chronic SCI (> 1 year). Quadriceps spasticity was measured by gravity-provoked stretch (Pendulum Test) before (initial) and after (final) a 3 day/week, 12-session WBV intervention. In addition, differences between immediate (immediate post-WBV) and delayed (delayed post-WBV) within-session effects were quantified. Finally, we assessed response differences between subjects who…did and those who did not use antispastic agents. Results: There was a significant reduction in quadriceps spasticity after participation in a WBV intervention that persisted for at least eight days. Within a WBV session, spasticity was reduced in the delayed post-WBV test compared to the immediate post-WBV test. The WBV intervention was associated with similar changes in quadriceps spasticity in subjects who did and those who did not use antispastic agents. Conclusions: Vibration may be a useful adjunct to training in those with spasticity. Future studies should directly compare the antispastic effects of vibration to those of antispastic agents.
Show more
Keywords: Spinal reflex, human movement system, rehabilitation, stretch reflex, reflex modulation, Pendulum Test
Abstract: BACKGROUND: A number of physiological and atmospheric variables are believed to increase spasticity in persons with spinal cord injury (SCI) based on self-reported measures, however, there is limited objective evidence about the influence of these variables on spasticity. OBJECTIVE: We investigated the relationship between physiological/ atmospheric variables and level of spasticity in individuals with SCI. METHODS: In 53 participants with motor-incomplete SCI, we assessed the influence of age, time since injury, sex, injury severity, neurological level of injury, ability to walk, antispasmodic medication use, temperature, humidity, and barometric pressure on quadriceps spasticity. Spasticity was assessed using the pendulum test first…swing excursion (FSE). To categorize participants based on spasticity severity, we performed cluster analysis. We used multivariate stepwise regression to determine variables associated with spasticity severity level. RESULTS: Three spasticity groups were identified based on spasticity severity level: low, moderate, and high. The regression analysis revealed that only walking ability and temperature were significantly related to spasticity severity. CONCLUSIONS: These outcomes validate the self-reported perception of people with SCI that low temperatures worsen spasticity. The findings refine prior evidence that people with motor-incomplete SCI have higher levels of spasticity, showing that those with sufficient motor function to walk have the highest levels of spasticity.
Show more