Upper limb
Carpal bones
Ossa carpi
- Origin
- 8 bones arranged in two rows: proximal (Scaphoid, Lunate, Triquetrum, Pisiform) and distal (Trapezium, Trapezoid, Capitate, Hamate)
- Insertion
- Anchorage for intrinsic thenar and hypothenar muscles, flexor/extensor retinacula, and wrist ligaments
- Function
- Forms flexible arch of the wrist and structural floor/walls of the carpal tunnel
- Innervation
- Median, ulnar, and radial (deep branch) nerves
- Movement & chain
- Wrist flexion, extension, radial and ulnar deviation, and intercarpal gliding
- Palpation
- Pisiform bone palpable at hypothenar crease; scaphoid palpable in anatomical snuffbox
- Clinical
- Scaphoid fracture (risk of avascular necrosis and non-union); lunate dislocation; carpal tunnel syndrome
- Segmental innervation
- C6–T1
- In clinical practice
- Palpation of anatomical snuffbox tenderness following fall on outstretched hand
- Region in the model
- Upper limb