Among tennis players the pinky side of the wrist is vulnerable to injury using the western grip variations and rotating the wrist besides the shoulder in the creation of topspin. The extensor carpi ulnaris tendon (ECU) is held in its ulna head groove by its subsheath.
The ligament tears with hypersupination forces (palm-up). Congenital shallowness of the bony trough places excess stress on the subsheath during a backhand with topspin. The nondominant wrist can be injured in a two-handed backhand slice. Forehand slices are implicated as well.
The triangular fibrocartilage complex (TFCC) is vulnerable during forceful wrist rotations in supination, pronation, and bending to the pinky side. The cartilagenous meniscus of the wrist and the ligaments tying the radius and ulna together comprise the TFCC.
Examination of tennis grip, technique, and conditioning are part of the treatment of wrist injuries, besides taping and bracing.