The Sweater Sign Test is a wrist examination procedure that tests for the rupture of the flexor digitorum superfiscialis tendon. This tendon is responsible for the flexion of the middle phalanges of the fingers along the proximal interphalangeal joints. It also flexes the metacarpophalangeal joints as well as the wrist joint. Another name for the Sweater Sign is Jersey Finger.
The patient should be awake and cooperative when the Sweater Sign test is done.
- Patient may be seated or standing.
- The examiner tells the patient to make a tight fist.
- The examiner checks the way the fingers are flexed and takes note of any difficulty in bending any digit.
Positive Sweater Sign Test
There is positive Sweater Sign when the patient is having difficulty bending the proximal finger and the distal phalanges. This could indicate rupture of the flexor digitorum superfiscialis tendon.
The name Jersey Finger was derived from the injury that a player suffers after attempting to grab another player’s jersey. Positive Sweater Sign should be followed by diagnostic imaging to rule out an avulsion fracure.