The description is consistent enough that I can usually predict the examination findings from the history alone: pain reaching into an overhead cupboard, pain putting on a jacket, pain reaching for a seatbelt, and a specific painful arc partway through raising the arm that eases again at the top. That is shoulder impingement, and it is the most common cause of shoulder pain we see.
What Is Actually Being Pinched
Your rotator cuff tendons — principally supraspinatus — pass through a narrow space between the top of the arm bone and the bony roof formed by the acromion. There is a bursa in there to reduce friction. When that space narrows, the tendon and bursa get compressed every time you raise your arm. Repeated thousands of times, that produces inflammation, then tendon degeneration, and eventually can progress to a tear.
The Part Most People Miss
Here is what makes impingement genuinely different from how it gets treated. The space narrows mostly because of how the shoulder blade moves, not because of anything wrong with the tendon itself.
Raising your arm properly requires your scapula to rotate upward and tilt back, which lifts the bony roof out of the way as the arm comes up. This is scapulohumeral rhythm. When the scapula does not do its part — because the lower trapezius and serratus anterior are weak, or because a tight pectoralis minor pins the scapula in a forward-tilted position — the roof stays where it is and the tendon gets squashed.
This is why resting an impinged shoulder often fails. Rest calms the inflammation, you feel better, you go back to reaching overhead with the same faulty mechanics, and it returns within weeks. The tendon was the victim, not the culprit.
Where the Neck and Upper Back Come In
Scapular mechanics depend on the thoracic spine underneath. A stiff, flexed mid-back physically prevents the scapula from rotating properly — you cannot get full overhead reach through a rounded thoracic spine, no matter how strong the shoulder is. Try it: slouch deliberately and raise your arm, then sit tall and repeat. The difference is obvious.
This is why treating an impinged shoulder without addressing the thoracic spine tends to disappoint, and why the same desk posture that produces neck and back pain also produces shoulder pain.
Distinguishing It From Other Shoulder Problems
- Frozen shoulder restricts motion in every direction, including when someone else moves your arm for you. Impingement is painful in specific arcs but the range is usually preserved. See frozen shoulder and rotator cuff problems.
- A significant rotator cuff tear typically produces weakness rather than just pain — difficulty holding the arm out to the side against resistance.
- Referred pain from the neck often includes symptoms below the elbow and does not change much with shoulder position. Cervical origin is easy to miss — see cervical radiculopathy.
- AC joint problems localise to the top of the shoulder and hurt most reaching across the body.
How It Is Treated
Effective treatment works on the mechanics, not just the symptoms. That means restoring thoracic spine mobility so the scapula can rotate, releasing the soft tissue that holds the scapula in a poor position — pec minor and upper trapezius in particular — and then progressively strengthening the muscles that control the scapula so the correction holds under load.
Symptom control matters early, because a shoulder that hurts constantly will not tolerate rehab. But it is the beginning of treatment, not the whole of it.
What to Stop Doing Meanwhile
Avoid the movements that reproduce the pinch: overhead pressing, upright rows, lateral raises above shoulder height. Sleeping on that side compresses the space all night — try the other side with a pillow supporting the affected arm. And stop the reflex of stretching hard into the painful range; you are pressing the tendon against the bone repeatedly.
Get the Mechanics Assessed
If overhead reaching hurts, the answer is usually in how your shoulder blade and mid-back move, not in the shoulder joint itself. Contact Bromberg Chiropractic in Cambridge for an assessment that looks at the whole system.
