hemiplegic shoulder pain and subluxation
/ hem-ee-PLEE-jik; sub-luk-SAY-shun /
The shoulder is the most mobile joint in the body, and it pays for that freedom with very little bony stability — it is held together mostly by muscles and a thin capsule, almost like a golf ball balanced on a tee. After a stroke, when the muscles around a paralysed shoulder go slack, the weight of the dangling arm can pull the ball partly out of its socket. This is shoulder subluxation, and the ache and damage that follow are among the most common and most preventable problems in stroke rehabilitation.
Early after the stroke the arm is flaccid, the rotator cuff and deltoid muscles cannot hold the joint up, and gravity drags the upper arm bone downward so a gap opens between it and the socket — you can sometimes feel a step under the skin. This stretching strains the capsule and the soft tissues. Later, as tone rises, a different mix of problems appears: spasticity pulls the arm into awkward positions, the shoulder gets pinched (impingement) during careless handling, and a painful stiff shoulder can develop. Pain may also feed into a broader condition (sometimes called shoulder-hand syndrome) with a swollen, painful hand. Mishandling — pulling the weak arm during transfers, letting it hang unsupported — makes it all worse.
In rehabilitation the watchword is protect and support. Careful positioning, supporting the arm in bed and in the wheelchair, training everyone (staff and family) never to drag the weak arm, and gentle pain-free range of motion are the staples. Supports such as slings or arm troughs and, in some programmes, electrical stimulation of the shoulder muscles are used, though the evidence for fully preventing pain is mixed. The honest point is that a painful shoulder is not a trivial side issue — it disrupts sleep, blocks therapy, and slows the whole recovery, so prevention beats treatment.
An aide lifts a stroke patient by tugging on her weak arm during a transfer. Over the next days the shoulder aches whenever it is moved, and the team can feel a fingertip gap between the arm bone and the socket. They switch to supporting the limb, retrain the transfer technique, and the pain settles enough for her to tolerate therapy again.
Never pull on the weak arm; support and careful positioning prevent most shoulder damage.
Subluxation and pain are linked but not the same — a shoulder can be subluxed yet painless, or painful without much subluxation. Slings rest the joint but, if overused, can encourage stiffness and neglect of the arm, so they are used judiciously.