Shoulder Impingement Research

Current research is moving away from calling this simply “shoulder impingement.” Researchers such as Jeremy Lewis, Christian Littlewood, Natalie Requejo-Salinas, and others have argued that the term rotator cuff–related shoulder pain or subacromial pain syndrome is often more accurate, because pain is not always caused by one structure being mechanically pinched under the acromion. The newer view is that shoulder pain usually involves a mix of rotator cuff tendon sensitivity, load intolerance, bursal irritation, scapular control, thoracic posture, cervical contribution, sleep, age-related tendon change, and nervous system sensitivity.

Researchers James Creech and colleagues describe shoulder impingement as involving the rotator cuff tendons and subacromial bursa, often with tendon degeneration, collagen disorganization, neovascular changes, and sometimes progression toward partial or full-thickness rotator cuff tearing. This does not mean every painful shoulder has a tear, or that every tear causes pain. Many imaging findings are common with aging, so current research warns clinicians not to treat MRI or ultrasound findings alone. The client’s pain behavior, weakness, movement tolerance, irritability, sleep disturbance, and response to loading matter more than a single structural label.

A major research shift concerns surgery. Mika Paavola and the FIMPACT research group found that arthroscopic subacromial decompression did not provide meaningful benefit over placebo surgery or exercise therapy at five-year follow-up. A later ten-year follow-up by Kanto and colleagues again reported no long-term advantage of decompression surgery over placebo surgery or exercise therapy for subacromial pain syndrome. This is important for massage therapists because many clients still believe a hooked acromion or “bone spur” is the main reason they hurt. The evidence suggests that removing bone or clearing space is rarely the simple answer for persistent nontraumatic shoulder pain.

Exercise remains one of the most supported conservative treatments, but the research is not saying that one perfect exercise fixes everyone. A 2024 JOSPT systematic review on rotator cuff–related shoulder pain examined exercise dosage, frequency, intensity, time, and type, showing that exercise is helpful but still variable in how it is prescribed. The practical message is that gradual strengthening, progressive exposure, and symptom-guided loading are more useful than telling every client to avoid overhead movement completely. For manual therapists, this means hands-on work may reduce guarding and improve comfort, but long-term change usually requires the shoulder to regain tolerance to reaching, lifting, pushing, pulling, and sleeping positions.

Scapular research is also active. Zhong and colleagues published a 2024 systematic review on scapular stabilization exercises for subacromial pain syndrome and found support for improving pain and function. Wen and colleagues published a 2025 randomized trial comparing scapular dyskinesis-based exercise therapy with multimodal physical therapy, reflecting the growing interest in matching care to the client’s actual movement pattern instead of using a generic protocol. This matters because some clients elevate the shoulder early, some under-rotate the scapula, some overuse upper trapezius, and others lack posterior cuff endurance.

Biomechanics research by Lawrence and colleagues helps explain why scapular motion still matters, even though “impingement” is too simple as a diagnosis. Their 2024 study found that changes in scapular upward rotation, external rotation, and anterior tilt can alter the distance between rotator cuff tendon insertions and surrounding shoulder structures. Clinically, this supports observing how the scapula behaves during arm elevation, lowering, wall slides, loaded reaching, and fatigue. The goal is not to force a “perfect” scapular position, but to help the client find smoother, less painful, better-supported shoulder movement.

Manual therapy research is mixed but still relevant. Benjamin Hando, Daniel Rhon, and colleagues published a sham-controlled randomized clinical trial on manual therapy plus exercise for subacromial pain syndrome. The larger trend suggests that manual therapy may help pain, range of motion, and short-term function when paired with exercise, education, and graded loading, but it should not be presented as a stand-alone cure. For massage therapists, the strongest role is likely reducing protective tone around the posterior shoulder, pectoralis minor, latissimus, upper trapezius, levator scapulae, cervical region, and thoracic spine while helping the client move with less threat.

Corticosteroid injection research shows short-term usefulness for some clients but less certainty long term. Studies by Ellegaard and colleagues and by Roddy, Ogollah, Oppong, Foster, and the SUPPORT trial group have examined injection, exercise, and outcomes in subacromial pain. The pattern is that injections may reduce pain temporarily, especially when irritability is high, but they do not replace progressive rehabilitation. For manual therapists, this means a client may feel better after an injection, but the tissue capacity problem may still remain. The safer clinical message is to coordinate with medical providers and avoid overloading the shoulder simply because pain is temporarily reduced.

Another current theme is nervous system sensitivity. Chen and colleagues studied joint position sense therapy in chronic shoulder pain and central sensitization, reflecting broader interest in proprioception, pain amplification, and motor control. Chronic shoulder pain is not always proportional to tissue damage. A client may have high pain with minor imaging findings, or a large tendon tear with little pain. This helps explain why calm education, sleep support, graded exposure, breathing, pacing, and confidence-building can matter alongside local tissue work.

For the manual therapy community, the clearest research-based message is this: shoulder impingement is better understood as a load, movement, tendon, bursa, scapular, cervical-thoracic, and pain-system problem rather than a simple pinching problem. Assessment should include painful arc, resisted external rotation, abduction strength, scapular movement, thoracic mobility, cervical referral, sleep position, work demands, training errors, and irritability level. Treatment should combine comfort-based manual therapy with progressive movement, not aggressive digging into painful tissue. The best outcomes usually come from helping the client calm symptoms, restore confidence, rebuild rotator cuff and scapular endurance, and gradually return to meaningful overhead function.