Shoulder pain

What it is

The shoulder trades stability for range. The ball sits on a shallow socket and is held centred almost entirely by muscle - the four rotator cuff muscles - while the shoulder blade underneath has to rotate and tilt to keep the socket pointing where the arm is going.

When the cuff and the scapular muscles are weak or fatigued, the head of the humerus drifts upward during elevation and the tissues in the narrow space above it get compressed and irritated. Add a tight posterior capsule and short pecs and the drift gets worse. This is why strengthening usually beats resting, and why surgery for subacromial pain has repeatedly failed to outperform exercise in trials.

What it feels like

• Pain in a band on the outer upper arm rather than on the point of the shoulder
• Worst in an arc partway through raising the arm, easier again at the top
• Reaching into a back pocket, fastening a bra or putting on a coat is the awkward movement
• Aching at night, particularly lying on that side
• Weakness that could be genuine or could be pain inhibiting the effort

What causes it

Most people have more than one of these at once, and they feed each other. Read the list looking for the two or three that sound like your week rather than for the one true answer — the ones that describe you are the ones worth acting on.

Rotator cuff weakness

Supraspinatus, infraspinatus, teres minor and subscapularis hold the ball centred on the socket. Weak or fatigued, they let it ride up during elevation, compressing what sits above it.

Weak scapular stabilisers

Lower and middle traps and serratus anterior rotate the shoulder blade upward as the arm rises. Without that rotation the socket does not follow the arm, and the space available shrinks at exactly the wrong moment.

A tight posterior capsule

Tightness at the back of the joint pushes the head of the humerus forward and up during elevation. It is common in anyone who has done a lot of throwing or racquet sport, and it responds to specific stretching.

Short pecs and lats

Both hold the arm internally rotated and the shoulder blade forward, so the arm starts every movement from a disadvantaged position.

A stiff thoracic spine

The last part of raising the arm overhead requires the upper back to extend. If it cannot, the shoulder is asked to find the range on its own, which it does by compressing the very tissue that hurts.

A sudden increase in overhead load

Painting a ceiling, a weekend of decorating, a new gym programme with pressing in it. The tissue tolerance was fine for the old load and is not fine for the new one.

Age-related tendon change

Cuff tendons degenerate with age in almost everyone, and partial tears are common in pain-free shoulders. Their presence on a scan does not establish them as the cause of the pain.

Sleeping on that side

Six or eight hours of body weight compressing the shoulder is a sustained load nothing in the daytime matches. Night pain is often as much cause as symptom.

Neck referral

A cervical nerve root problem refers pain into the shoulder and upper arm convincingly. If the shoulder itself moves fully and painlessly when tested, the neck is the place to look.

Fear and protective disuse

A painful shoulder gets used less, the cuff weakens further, and range is lost - which is the road to a frozen shoulder in some people and to a persistent weak painful one in most.

Who tends to get it

• Anyone whose work or hobby involves repeated overhead reaching
• Throwing and racquet sport players, in whom posterior capsule tightness is common
• Adults over forty, where cuff tendon change becomes common
• Side sleepers, particularly consistent one-side sleepers
• People with a rounded upper back or forward shoulders, which reduce the space available from the start

What makes it worse, and what settles it

The qFIT routine for this

Ready-made routineShoulder Relief & Overhead Range

qFIT already has this one built. It runs massage first, then stretching, then strength — the order that works on a body that is already sore — and every activity in it carries the reason it is there.

The button below opens your Checklist with this routine already selected, so instead of your whole list you land on just its Categories, Targets and Exercises, each with its checkbox, ready to tick as you work through them.

Have more than one problem? Tick yours under My Problems on My Profile and your Checklist's Routine list gains Recommended for my problems — every routine for the problems you picked, merged into one. Your picks stay private; that filter is the only thing they feed.

Get it checked if…

Inability to lift the arm at all after trauma; night pain with fever; visible deformity

And whatever the body part: chest pain or unusual breathlessness on exertion; a fever alongside the pain; unexplained weight loss; pain that is constant and unrelated to how you move; new numbness, weakness or loss of bladder or bowel control; or one calf that is swollen, warm and painful. Any of those, stop and get assessed.

How it usually goes

Most subacromial shoulder pain improves substantially with twelve weeks of consistent, progressive strengthening, and trials repeatedly show exercise matching or beating surgery for this presentation. It is slower than people expect and the first few weeks can feel like nothing is happening. A shoulder that cannot be lifted at all, that followed a significant injury, or that is losing range in every direction is a different problem - a full-thickness tear or a frozen shoulder - and needs assessing rather than training blind.

Prevalence basis: POLAR primary-care database; rotator cuff tendinopathy annual prevalence 0.5-7.4%

Others the same routine covers

These share the Shoulder Relief & Overhead Range routine, so the work is the same. If one of them also sounds like you, that is a reason to expect more from it, not less.

This is general information, not a diagnosis, and it cannot examine you. If it matches you, use it to ask better questions of a clinician rather than to replace one.