Effect of Continuous Passive Motion on the Surface Electromyography of Gastrocnemius Muscle in Stroke Patients

Objective:To observe the change of the surface electromyography (sEMG) on gastrocnemius muscle in stroke patients after continuous passive motion of ankle. Methods: Fifteen stroke patients (observation group) and 15 normal subjects (control group) were involved in this study. All subjects were subjected to continuous passive motion of ankle on the affected sides in observation group and on the corresponding side in control group at the angular velocity of 5°/s for 5 min or 10 min respectively. Before and after the motion, the root mean square (RMS) value of sEMG and composite spasticity scale (CSS) scores in the two groups were compared. Results: Before the continuous passive motion, the RMS values (3.0±1.4, 3.4±1.8) of gastrocnemius muscle in observation group (5 min or 10 min) were higher than those in control group (1.8±0.9, 1.7±0.8) (P0.01). In observation group, the RMS values (1.8±0.8, 1.9±1.0) of gastrocnemius muscle and CSS scores (12.1±3.3, 12.2±2.0) after the continuous passive motion were lower than before (CSS scores 14.5±1.7, P0.01, P0.05). There was no significant difference in the RMS values and CSS scores between the 5 min and 10 min movement in observation group. Conclusion: Continuous passive motion is an effective therapy for patients with gastro chemius muscle spasticity after stroke. SEMG can quantitatively estimate muscle spastcity.