What is it?
The most common cause is overuse of the tendon but it can also be caused by Arthritis and infection
Tenosynovitis is inflammation on the sheath that covers a tendon. As well as swelling, pain and tenderness are also present, which can cause the joint moved by the tendon to become stiff.
Resting orthoses are used in the early stages to reduce pain and inflammation by reducing the excursion (movement range) and glide of tendons.