Shoulder Muscle Tone, Function, and Factors Associated with Functional Recovery in Patients with Chronic Shoulder Pain: A Non-Randomized Comparative Study of Manual Therapy and Corticosteroid Injection

Background/Objectives: This study aimed to compare the effects of manual therapy (MT) and corticosteroid injection (CI) on shoulder muscle tone, function, and health-related quality of life (HRQOL) in patients with chronic shoulder pain (CSP) and to identify the muscle-tone change most strongly associated with functional recovery.

Methods

In this quasi-experimental, non-randomized study, 44 patients with CSP lasting >6 months were allocated to MT (n = 22) or CI (n = 22) according to the treating physician’s judgment. Each group received the assigned intervention for 4 weeks, together with conventional physical therapy and a home-based exercise program. Muscle tone (upper trapezius, anterior deltoid, posterior deltoid, and latissimus dorsi [LD]), the Patient-Specific Functional Scale (PSFS), and HRQOL were assessed at the baseline and at 2 and 4 weeks. Exploratory linear regression analyses examined factors associated with changes in PSFS scores.