Upper limb
Flexor retinaculum of the hand, carpal tunnel & flexor tendon sheaths
Retinaculum flexorum manus et vaginae tendinum flexorum
- Origin
- Scaphoid tubercle and trapezium crest (radially); pisiform and hook of hamate (ulnarly)
- Insertion
- Bridges carpal arch to form carpal tunnel; continuous with palmar aponeurosis and digital fibrous sheaths
- Function
- Forms roof of carpal tunnel, preventing bowstringing of 9 flexor tendons and median nerve; synovial sheaths provide low-friction excursion
- Innervation
- Palmar cutaneous branch of median nerve and ulnar nerve (C6–T1)
- Movement & chain
- Converts forearm flexor pull efficiently into finger grip
- Palpation
- Palpable across proximal palm at heel of hand
- Clinical
- Carpal tunnel syndrome (median nerve compression presenting with nocturnal paresthesia in thumb/index/middle fingers; positive Phalen/Tinel); trigger finger; infectious flexor tenosynovitis (Kanavel signs).
- Segmental innervation
- C6–T1
- In clinical practice
- Phalen and Tinel testing, neutral wrist night splinting, corticosteroid injection, and surgical open/endoscopic carpal tunnel release
- Region in the model
- Upper limb