Effects of resistance training and neuromuscular electrical stimulation in knee osteoarthritis : a randomised control trial.
This study compared the effects of 6-week home-based resistance training (RT) and neuromuscular electrical stimulation (NMES) programs on self-reported disability, functional capacity, quadriceps strength and cross-sectional area (CSA), and expression of myosin heavy chain (MHC) isoforms and ubiquitin-protein ligases in older persons with moderate to severe knee osteoarthritis (OA).
A total of 41 patients aged 55 to 75 years with arthroscopically or radiographically confirmed moderate to severe knee OA were randomised to a 6-week home RT program, a 6-week NMES program or a control group receiving standard care. The RT group performed quadriceps femoris strengthening exercises 3 times per week, while the NMES group used a portable garment stimulator for 20 minutes 5 times per week at the maximum intensity comfortably tolerated.
Outcomes were assessed at baseline, post-intervention and 6 weeks post-intervention. The primary outcome measure was self-reported disability, measured using the Short Form Health Survey (SF-36) score and the Western Ontario McMaster Universities Arthritis (WOMAC) index. Secondary outcome measures were functional capacity (25m walk test, chair rise test, stair climb test), peak isometric and isokinetic quadriceps torque, quadriceps CSA, and expression of MHC isoforms, muscle atrophy F-box (MAFbx) and muscle RING finger-1 (MuRF).
There was no significant change in any of the outcome measures in the control group. Compared to baseline, SF-36 scores, functional capacity and CSA increased significantly in the NMES and RT groups post-intervention. WOMAC scores increased significantly in the NMES group. Isometric peak torque did not change in any group. Adherence was 91% and 83% in the NMES and RT groups respectively (p=0.324). There were no between-group or withingroup differences in MHC isoforms, MAFbx and MuRF. At 6-week follow-up, functional improvements were maintained for both training groups, while most of the health score gains were lost.
Home-based NMES is an acceptable alternative to exercise therapy in the management of knee OA, especially for patients who have difficulty complying with an exercise program.