Twenty-six patients with medium-sized degenerative supraspinatus tears status-post arthroscopic rotator cuff repair (ARCR) were randomized to receive depressor muscle coactivation (DM-Co-A) training plus 14 weeks of guideline-based rehabilitation (n=13) or the same rehabilitation alone (n=13). The primary outcome of interest was pain (VAS at rest, during activity, Neer, and Hawkins-Kennedy positions) and active ROM (flexion, abduction, external/internal rotation). Secondary outcomes included DASH, Revised Oxford Shoulder Score (ROSS), Modified Constant-Murley Score (MCMS), and WORC. Outcomes were assessed across a 14-week program. Overall, the results revealed greater improvements with DM-Co-A in pain, flexion/abduction/external rotation ROM, and all functional scales; internal rotation ROM did not differ. These findings suggest adding EMG-guided DM-Co-A to standard rehab yields modest but clinically meaningful postoperative gains after ARCR.