Feasibility of Heavy Slow Resistance Training in patients with subacromial shoulder pain. A single-blind, randomized pilot study.
Abstract Background: Subacromial shoulder pain is the most common shoulder diagnosis, and should preferably be treated non-operatively. Previous studies have shown promising results of Heavy Slow Resistance training (HSR) in patellar and Achilles tendinopathy, but few studies have evaluated the effect of HSR for shoulder pain. The purpose of this pilot trial was to evaluate if HSR training is feasible for patients with subacromial shoulder pain, and to compare HSR to traditional supervised exercises. Methods: Twenty-two patients with subacromial shoulder pain lasting at least three months were recruited and randomized to HSR (n=11) or traditional supervised exercises (n=11) by computer-generated randomization in blocks of four. Patients received HSR once a week, in addition to home-training twice a week, or supervised exercises twice a week for 12 weeks, in addition to daily home-training. The primary outcome measure was the Shoulder Pain and Disability Index (SPADI). Linear regression analysis was applied to evaluate the between group differences after 12 weeks. Outcome assessors were masked. Results: After 12 weeks, patients in both groups had improved significantly from baseline in SPADI score (P=0.001) but no group difference was found (mean difference 1.3; 95% CI, -21.9 to 24.5, P=0.91). Similar non-significant results between groups were seen for pain in activity and rest, and the DASH score. Conclusion: This pilot-study observed similar results of HSR compared to supervised exercises for patients with subacromial shoulder pain and both groups improved significantly from baseline. Only one patient changed from HSR to supervised exercises due to increased pain. Based on this, HSR appears to be a feasible treatment for this patient group, but due to small sample size there is a risk of type II error and studies with larger sample size are required.