Effects of ankle proprioceptive interference on locomotion after stroke

Objective: To examine the effects of vibration-induced ankle proprioceptive interference on the locomotion of patients with stroke with intact and impaired ankle joint position sense (JPS). Design: Cross-sectional. Setting: Rehabilitation department in a tertiary hospital. Participants: Ambulatory patients (N=35) with unilateral stroke received an ankle joint repositioning test and were classified into intact (n=16) or impaired (n=19) JPS group. Interventions: None. Main Outcome Measures: The plantar sensitivity and leg muscle strength were tested. Patients were instructed to walk at a self-selected pace on a computerized pressure sensor walkway under 3 conditions: no, affected, or unaffected Achilles' tendon vibration. The stride characteristics of the affected limb were analyzed. Results: Patients with intact and impaired JPS did not differ in their plantar sensitivity or leg muscle strength. The differences in the stride characteristics were nonsignificant between vibration and nonvibration conditions. Shorter single support and longer swing phase were found with the affected side vibration compared with the unaffected side vibration. Patients with intact and impaired JPS did not respond to the proprioceptive interference differently. Conclusions: After stroke, there could be changes in the central sensory regulation for locomotion control and vibration-induced afferent inputs from the ankle might be viewed as sensory disturbances. Further studies that manipulate other sensory inputs are needed to gain a better understanding of the central sensory integration for locomotion control after stroke.