Rotator Cuff Tendinopathy Explained (Formerly 'Tendinitis')

The rotator cuff is a group of four muscles that wrap around the shoulder joint. They help hold the ball of the upper arm bone in its socket while the arm moves. Their tendons are the tough cords that attach those muscles to the bone.

A tendinopathy is a painful tendon that is not coping well with the load placed on it. A 2025 review describes rotator cuff-related shoulder pain as the most common cause of shoulder pain. That group includes pain from the space above the tendons, from tendinopathy and from some tears [R03].

Common signs include pain with reaching overhead, lifting, reaching behind the back, or lying on the affected side. Only a clinician can tell whether this is what you have.

A common explanation is that a tendon adapts to the load it is asked to handle, and can become sore when the load rises faster than its capacity. Rest reduces the load but may not rebuild capacity, so many clinicians aim the plan at gradually rebuilding it.

• Specific exercise helps. The 2025 review found that mobilization and stretching improved function and pain over about two months. Scapular stabilization exercise also improved pain and function [R03].
• Progressive resistance probably helps. Resisted exercise that gets a little harder over the weeks probably helps. Gentle, unloaded movement alone probably does not move the needle much on pain [R01].
• Motor control may edge out generic exercise. Programs that teach control and coordination reduced disability slightly more than non-specific exercise in the short and medium term. The reason is not fully known [R02].
• Exercise helps in middle age and later. In middle-aged and older adults, exercise interventions reduced pain and improved function and range of motion [R04].

1. Get assessed first. A doctor or physiotherapist can check for tears, nerve symptoms and other causes of shoulder pain. Imaging is not always needed. NHS England now advises against routine scans unless a treatment pathway exists [R30].
2. Use pain as a guide. Many physiotherapists suggest mild, short-lived discomfort that settles by the next day is often acceptable. Sharp pain, or pain that keeps getting worse, is a reason to ease off and talk to your clinician.
3. Start with a seated, clinician-guided plan. Seated isometric holds are a common starting point. Press the back of your hand gently against a wall or against your other hand, hold briefly, then release. Keep the effort light and the pain low.
4. Keep moving at a comfortable level. Walking and everyday arm use, kept within your comfort range, are often part of a plan. Complete rest for weeks is rarely the goal.
5. Adjust how you sleep. Many people with one-sided shoulder pain sleep on the painful side. That is an association, and the cause is not known, so it is worth experimenting with position and a supportive pillow [R29].