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

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+/-15.2y; days post-CVA, 38.4+/-40.0d). 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 2X4 repeated-measures analysis of variance was performed on measurements at 4 intervals: pretest, I 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.