The objective of this study is to identify how the suppression of reflex function by antispastic agents affects volitional movement in people with incomplete spinal cord injury (SCI). Spastic reflexes are commonly treated using medications or other therapeutic approaches without a good understanding of how the subsequent changes in reflex function affect volitional movements, including gait. This study aims to improve our understanding of how reflexes affect functional movements and the impact that oral medications have on reflex regulation of movement in people with incomplete SCI. We will test the effect of two commonly prescribed antispastic oral medications, baclofen and tizanidine, on the reflex regulation of volitional muscle activity and gait. We expect that reflex excitation contributes to the generation of muscle activity during volitional tasks, and antispastic agents will depress reflexes and reduce muscle activity of the legs during gait. A comparison of the effects of reflexes on volitional movements, including gait, and sensitivity to antispastic agents will be made to gain an improved understanding of how different types of incomplete SCI patients utilize reflex activation of muscles to facilitate movement. We anticipate that subjects with greater weakness might rely heavily on reflexes for the generation of muscle activity during movement, and could be detrimentally affected by antispastic medications. This study has important implications for therapies aimed at restoring movement in SCI and for the treatment of spasticity to improve functional movements.
This research project is expected to have a direct impact on the clinical management of rehabilitation in people with spinal cord injury. The results from this study will provide the guidelines for the use of oral medications to improve functional movement, including walking, in people with incomplete spinal cord injury.
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