DeQuervain’s tenosynovitis

DeQuervain’s tenosynovitis is characterized by irritation or swelling of the tendons on the thumb side of the wrist. The inflammation thickens the tendon sheath (tenosynovium) and constricts the tendon as it glides in the sheath.  Among athletes this syndrome occurs in discus throwers and golfers as a result of repetitive extensive ulnar deviation of the wrist. 

Pathogenesis: 

Ulnar deviation of the wrist strains the tendons of the abductor pollicis longus and the extensor pollicis brevis muscles under