Why does shoulder osteoarthritis cause shoulder stiffness?

Cartilage normally helps the shoulder surfaces glide. With osteoarthritis, the joint may become rougher and irritated, and the lining can react with swelling. Pain can make the surrounding muscles tighten, which further reduces the arm's comfortable range. Stiffness may be most noticeable after rest or when reaching overhead, behind your back, or across your body. Reduced use can gradually make everyday movements feel harder.

Gentle, regular movement can help preserve the range you still have. Warmth before activity may make motion more comfortable for some people. Avoid forcing the arm through sharp pain or holding it still for long periods. A physiotherapist can select mobility and strengthening exercises that match your symptoms, while a doctor can discuss pain-relief options and whether further assessment is needed.

Book an assessment if stiffness is worsening, interferes with sleep or personal care, or comes with persistent pain, weakness, or swelling. Seek prompt care after a fall or other injury, especially if the arm cannot be lifted. Sudden severe pain with a visibly abnormal shoulder requires urgent evaluation.

Ask which movements to practise, how to protect the joint during work or exercise, whether physiotherapy is suitable, and how to tell ordinary stiffness from a new injury.