A thumb splint may be useful to rest the region of the first carpometacarpal joint for repetitive movement disorders including trigger thumb, de Quervain's tenosynovitis, and osteoarthritis. The splint immobilizes the wrist in a small degree of extension and radial deviation, while maintaining slight extension of the first metacarpophalangeal (MCP) joint.
Reproduced with permission from Sheon RP, Moskowitz RW, Goldberg,VM. Soft Tissue Rheumatic Pain: Recognition, Management, Prevention, 3rd ed, Williams & Wilkins, Baltimore 1996.