Anodal Transcranial Direct-Current Stimulation to Enhance Rehabilitation in Individuals With Rotator Cuff Tendinopathy: A Triple-Blind Randomized Controlled Trial

BACKGROUND: Anodal transcranial direct-current stimulation (a-tDCS) has been shown to enhance the effects of sensorimotor training in neurological populations. Sensorimotor training leads to reduced pain and increased function in the treatment of rotator cuff tendinopathy. The addition of a-tDCS during a rehabilitation program centered on sensorimotor training may improve treatment outcomes in individuals with rotator cuff tendinopathy. OBJECTIVE: To compare 2 groups of individuals with rotator cuff tendinopathy, one receiving a rehabilitation program centered on sensorimotor training with a-tDCS and the other receiving the same rehabilitation program with sham a-tDCS. METHODS: In this triple-blind, parallel-group randomized controlled trial, 40 adults with rotator cuff tendinopathy participated in a 6-week rehabilitation program (8 treatments with home exercises and including sensorimotor training, patient education, and strengthening). They were randomly assigned to 1 of 2 groups to receive either real a-tDCS (stimulation, 1.5 mA for 30 minutes) or sham a-tDCS during the first 5 treatments. Symptoms and functional limitations (Disabilities of the Arm, Shoulder and Hand questionnaire, Western Ontario Rotator Cuff index) of all participants were evaluated at baseline and at 3, 6, and 12 weeks. Acromiohumeral distances (ultrasonographic measurement at 0 degrees, 45 degrees, and 60 degrees of arm elevation) were assessed at baseline and 6 weeks. Two-way or 3-way repeated-measures analyses of variance were used for statistical analyses. RESULTS: Both groups showed statistically significant improvement in Disabilities of the Arm, Shoulder and Hand questionnaire and Western Ontario Rotator Cuff index scores at 3, 6, and 12 weeks, and in acromiohumeral distance at 45 degrees and 60 degrees at 6 weeks (P<. 05). No significant group-by-time interaction was observed for all outcomes (P>. 43). CONCLUSION: Results do not demonstrate any improved treatment outcomes from the addition of a-tDCS during a rehabilitation program for individuals with rotator cuff tendinopathy.