Effect of an electric stimulation facilitation program on quadriceps motor unit recruitment after stroke.

ABSTRACT

OBJECTIVE: To compare maximum voluntary isometric torque (MVIT) and motor unit recruitment of the quadriceps after an electric stimulation facilitation program in persons affected by cerebrovascular accident (CVA). DESIGN: Three-week, randomized controlled trial with an electric stimulation facilitation program added to standard care. SETTING: Inpatient rehabilitation center. PARTICIPANTS: Twenty patients receiving rehabilitation for first-time CVA (51.8+/-15.2 y; days post-CVA, 38.4+/-40.0 d). Patients were randomly assigned to study and control groups. INTERVENTIONS: All patients received standard physical therapy (PT) care. In addition, the study group received an electric stimulation facilitation program during weight-bearing and ambulatory activities of the PT program. MAIN OUTCOME MEASURES: MVIT and motor unit recruitment measured by interpolated twitch testing. A 2 x 4 repeated-measures analysis of variance was performed on measurements at 4 intervals pretest, 1 week, 2 weeks, and 3 weeks. RESULTS: MVIT increased by 77% in patients receiving electric stimulation, compared with a 31% increase for the control group. There was a significant effect for assessment time only. Motor unit recruitment increased from 35% to 53% for the study group, whereas the control group recorded no change in recruitment ability. A significant interaction was recorded, indicating improved motor unit recruitment for the study group. CONCLUSIONS: A brief and dynamic electric stimulation facilitation program significantly improved motor unit recruitment in persons after CVA.