Electrical stimulation plus progressive resistance training for leg strength in spinal cord injury: a randomized controlled trial

A randomized controlled trial. To determine the effectiveness of electrical stimulation (ES)-evoked muscle contractions superimposed on progressive resistance training (PRT) for increasing voluntary strength in the quadriceps muscles of people with spinal cord injuries (SCI). Sydney, Australia. A total of 20 people with established SCI and neurologically induced weakness of the quadriceps muscles participated in the trial. Participants were randomized between experimental and control groups. Volunteers in the experimental group received ES superimposed on PRT to the quadriceps muscles of one leg thrice weekly for 8 weeks. Participants in the control group received no intervention. Assessments occurred at the beginning and at the end of the 8-week period. The four primary outcomes were voluntary strength (Nm) and endurance (fatigue ratio) as well as the performance and satisfaction items of the Canadian Occupational Performance Measure (COPM; points). The between-group mean differences (95% confidence interval (CI)) for voluntary strength and endurance were 14 Nm (1–27; P=0.034) and 0.1 (−0.1 to 0.3; P=0.221), respectively. The between-group median differences (95% CI) for the performance and satisfaction items of the COPM were 1.7 points (−0.2 to 3.2; P=0.103) and 1.4 points (−0.1 to 4.6; P=0.058), respectively. ES superimposed on PRT improves voluntary strength, although there is uncertainty about whether the size of the treatment effect is clinically important. The relative effectiveness of ES and PRT is yet to be determined.