Situation: A 68-year-old man is on the medical ward on day 4 after an ischemic stroke in the right cerebral hemisphere. He did not receive reperfusion therapy. He has left-sided weakness, is alert, and has hypertension. He passed a bedside swallow screen yesterday. He now sits in a wheelchair for 2 hours each afternoon. His left arm is flaccid. Which action protects his left shoulder?

The weight of a flaccid arm pulls the humeral head down and causes shoulder subluxation and pain. The arm is supported on a pillow or lap tray, positioned with the elbow extended and palm up, and never pulled on during transfers or repositioning.

Why the left shoulder is at risk

After a right hemispheric ischemic stroke, the contralateral left arm is often flaccid during the early phase. In the flaccid stage, the rotator cuff muscles and other shoulder stabilizers lose tone, so they can no longer hold the humeral head snugly in the glenoid fossa. Gravity then pulls the humerus downward, widening the acromion-humeral gap and producing glenohumeral subluxation ^[2]. This downward displacement is the main mechanical cause of shoulder pain and secondary injury in hemiplegic patients ^[1][4].

The weight of a flaccid arm hanging unsupported from a wheelchair is enough to stretch the joint capsule and surrounding soft tissue, causing subluxation and pain. Therefore, the priority is to eliminate the downward pull of gravity on the humerus.

Why option 1 is correct

Supporting the left arm on a lap tray or pillow lifts the humerus back toward the glenoid and keeps the shoulder in a neutral, protected position. The forearm should rest with the elbow extended and the palm up to avoid internal rotation and elbow flexion contracture. Positioning the arm this way reduces traction on the joint capsule and helps prevent subluxation during prolonged sitting ^[1][3].

Why the other options are harmful

Action	Problem
Lifting under both arms	Pulling upward under the axilla directly stresses the unsupported shoulder joint and can worsen subluxation or injure the brachial plexus. Transfers must never use the affected arm as a handle [1].
Letting the arm hang down	Gravity pulls the humeral head downward, increasing the acromion-humeral gap and stretching the capsule. This is the exact mechanism that causes subluxation [2].
Elbow bent, hand fisted	This flexed, internally rotated posture promotes spasticity and contracture. It does not support the humerus and can increase shoulder pain over time [1][3].

Clinical application for nursing care

Positioning management is a core nursing intervention after stroke. When the patient sits in a wheelchair, the affected arm should be supported so the shoulder is not pulled downward. During repositioning or transfer, the arm must be moved gently and never pulled. Proper positioning and transfer technique are the most important nursing actions for reducing shoulder injury in hemiplegic patients. Gentle range of motion and functional electrical stimulation may also help reduce subluxation, but these are usually performed with physiotherapy involvement and do not replace basic protective positioning ^[1][4].

Key point! The flaccid shoulder subluxates because gravity overcomes absent muscle tone. Support the humerus, keep the elbow extended with the palm up, and never pull on the affected arm.

Watch out! Lifting under the arms during transfers is a common mistake that can directly injure the shoulder and brachial plexus. Use a transfer belt or support the trunk instead.