Strength training with electrical stimulation has no or little effect on the very weak muscles of patients with spinal cord injury: a randomised trial

Abstract

Is electrical stimulation (ES) combined with strength training and usual care more effective than usual care alone in increasing the strength of very weak muscles in people with recent spinal cord injury (SCI)? A randomised controlled trial with concealed allocation, intention-to-treat analysis and blinded outcome assessors. Sixty participants with recent SCI were recruited from three SCI units in Australia and Bangladesh. Participants were randomised to either a treatment or control group. A major muscle group of the upper or lower limb with Grade 1 or Grade 2 strength on a standard 6-point manual muscle test was selected. Participants in the experimental group received strength training combined with ES and usual care for the target muscle group over 8 weeks. Participants in the control group received only usual care. Assessments were undertaken by a blinded assessor at baseline and 8 weeks. The primary outcome was voluntary muscle strength on a modified 13-point manual muscle test. The three secondary outcomes were participants' perceptions of strength, function and ability to perform self-selected goals. The mean between-group difference for voluntary strength at 8 weeks was 0.7 out of 13 points (95% CI -0.7 to 2.1), where the clinically worthwhile treatment effect was deemed a priori as 1 point. None of the secondary outcomes demonstrated a clinically important effect. Strength training combined with ES over 8 weeks has a negligible effect on the strength of very weak muscles in people with SCI.