Initial Conservative Management of Subacromial Impingement Syndrome

NSAID Therapy

For adult patients with subacromial impingement, initiate oral or topical non‑steroidal anti‑inflammatory drugs (NSAIDs) combined with referral to physical therapy for supervised external‑rotation and abduction exercises. Moderate‑certainty evidence supports this approach. 1
Oral NSAIDs (e.g., ibuprofen, naproxen) and topical NSAIDs provide equivalent short‑term pain relief, reducing pain by approximately 1 cm on a 10‑cm visual analogue scale within 1–7 days. Moderate‑certainty evidence. 1
Continue the NSAID trial for 2–4 weeks as the initial course. 2

Supervised exercises that specifically target external rotation and abduction help prevent progression to frozen shoulder; limited external rotation is strongly associated with persistent pain. 3
Begin active and active‑assisted range‑of‑motion exercises immediately to avoid muscle atrophy and deconditioning. [3][2]
Overhead pulley exercises should be avoided because uncontrolled abduction may worsen impingement symptoms. [3][2]
Incorporate gentle, progressive stretching and mobilization of the glenohumeral joint and scapulothoracic articulation. 3

Cryotherapy (ice applied with a wet towel for 10‑minute intervals) provides immediate pain relief by decreasing tissue metabolism and the inflammatory response. [3][2]
Advise relative rest: avoid overhead and repetitive loading that reproduces pain, but do not immobilize the shoulder. 2

Reserve a single subacromial corticosteroid injection for patients who show no clinical improvement after 2–4 weeks of NSAIDs plus physical therapy. 2

The injection must be placed into the subacromial space (bursa) and never into the tendon substance to prevent weakening of tendon tensile strength and reduce the risk of rupture. [3][2]
Use strict aseptic technique; ultrasound guidance can improve injection accuracy. 3
Combine the corticosteroid with a local anesthetic (e.g., lidocaine) to achieve immediate analgesia. 2
After injection, avoid excessive joint use for 24 hours, but do not immobilize the shoulder. 3

Orthopedic (surgical) consultation should be considered only after 6–12 weeks of comprehensive conservative therapy (NSAIDs, physical therapy, and, if needed, corticosteroid injection). 3
Routine MRI is not indicated at initial presentation; it is reserved for cases with clinical suspicion of a full‑thickness rotator‑cuff tear (e.g., marked weakness ≤ 2/5 strength).

Time Frame	Recommended Actions	Evidence
Weeks 0–4	Oral or topical NSAIDs + supervised physical therapy (external rotation & abduction focus) + cryotherapy + relative rest	[1][3][2]
Weeks 4–6	If no improvement, add a single subacromial corticosteroid injection (or NSAID injection as a cost‑effective alternative)	[2]
Weeks 6–12	Continue physical therapy; reassess response to injection	[3]
> 12 weeks	If minimal improvement despite full conservative trial, obtain MRI to evaluate structural pathology and consider orthopedic referral for possible arthroscopic decompression	[3]

Do not inject corticosteroids into the tendon; limit injection to the subacromial bursa to prevent tendon rupture. [3][2]
Do not repeat corticosteroid injections without an adequate therapeutic response, as repeated dosing can impair healing and diminish tissue strength. 3
Do not order MRI before completing a trial of conservative therapy unless there is clear clinical evidence of a full‑thickness tear (e.g., profound weakness, positive drop‑arm test).
Avoid complete shoulder immobilization, which leads to muscular atrophy, deconditioning, and progression to frozen shoulder. Controlled tensile loading through gentle motion supports proper collagen synthesis and tendon alignment. [3][2]