M70: Soft tissue disorders related to use, overuse and pressure

M70.0: Chronic crepitant synovitis of hand and wrist

Tendons are made up of very firm connective tissue. Tendons attach muscles to bones. A tendon sheath is a covering for the tendon. It cushions the tendon and contains a small amount of fluid. This reduces friction between the tendon and its surroundings.

Over-use or repetitive movements can cause long-term inflammations of tendons and tendon sheaths. As a result the tendons and tendon sheaths may swell up and the surfaces can become rough. You can then feel or hear a rasping when the rough surfaces rub together. You may also have pain in your hand or wrist, particularly when moving them. It may also be that the pain makes it harder to move the hand.