Effects and Predictors of Effectiveness of Shoulder Muscle Massage for Patients With Posterior Shoulder Stiffness

The investigators investigated the effect and predictors of effectiveness of massage in the treatment of patients with posterior shoulder stiffness. This is a randomized controlled trial study- massage and control (hand touch) two times a week for 4 weeks. A total of 60 patients with posterior shoulder tightness were randomized into 2 groups; 52 of them completed this study (29 for the massage and 23 for the control). Patient sex, age, body mass index, glenohumeral internal rotation range of motion (ROM), duration of symptom, functional status, and muscle stiffness were recorded. Additionally, for the massage group, patients with glenohumeral internal rotation improvement of 20 degrees after massage were considered responsive, and the others were considered nonresponsive. The influences of the aftermentioned factors on the effectiveness of massage were analyzed by multivariate logistric regression. The overall mean internal rotation ROM increased significantly after massage (from 31.9° to 54.9°; P < 0.001) compared to the control (from 28.7° to 34.9°; P > 0.05). There were 22 patients in the responsive group and 7 in the nonresponsive group. Among the factors, duration of symptoms, FLEX-SF score, and posterior deltoid stiffness were significant predictors of effectiveness of massage. Massage was an effective treatment for subjects with posterior shoulder stiffness, but was less effective in patients with longer duration of symptoms, higher functional limitation, and less posterior deltoid stiffness.