The aim of this study was to compare the effectiveness of strength training combined with ES and usual care, versus usual care alone for increasing strength in very weak muscles of people with recent SCI.
Sixty people with recent SCI undergoing inpatient rehabilitation participated in this trial. Participants were randomised to either the treatment or control group. One target muscle group with less than 3 strength on a 13-point scale (equivalent to less than grade 3/5 on manual muscle testing) was selected from the following muscles: the elbow flexors, elbow extensors, wrist flexors, wrist extensors, knee flexors, knee extensors, ankle dorsiflexors or ankle plantarflexors. Participants allocated to the Treatment group received usual care as well as a progressive strength training programme with ES superimposed for one key muscle over 8 weeks. The training was provided three times a week and consisted of 120 contractions performed in sets of 10. The first 60 contractions were done with ES superimposed on maximal voluntary effort, and the other 60 contractions were done with ES alone. Participants allocated to the Control group received usual care alone. Participants were assessed at baseline and 8 weeks by a blinded assessor. The primary outcome was voluntary strength on a 13-point scale, and the secondary outcomes were participants’ perceptions of strength, function, and their ability to perform self-selected goals. The results were analysed by intention-to-treat using regression models.
There were no dropouts and adherence with the intervention was generally good except in one participant. The mean between-group difference for voluntary strength at 8 weeks was 0.7/13 points (95% confidence interval -0.7 to 2.1). This is less than the clinically worthwhile treatment effect of 1 point set a priori. The mean between-group difference for participants’ perception of change in strength and function, and their ability to perform self-selected goals were 0.4/15 points (95% CI -0.5 to 1.3), 0.5/15 points (95% CI -0.4 to 1.4) and 0.7/10 (-0.6 to 2.1), respectively.
The results indicate that ES combined with strength training has either no or very little effect on the strength of very weak muscles directly affected by SCI.
The failure to demonstrate a clear treatment effect in this trial raises further questions about the best way to strengthen very weak muscles after SCI. To date, the most effective method of increasing the strength of very weak muscles in the initial months following SCI remains unclear.
Spinal Cord Injuries
Strength Training
