Shoulder impingement can be successfully treated with: NSAIDs: 6-8 week regiment. Physical therapy Avoidance of repetitive overhead activity Corticosteroid injection: If other treatments are unsuccessful. Subacromial decompression: In rare cases, a surgical procedure is performed which expands the space between the acromion and the rotator cuff tendons. Most shoulder impingement patients recover fully within a few weeks, depending on symptom severity and treatments.