Expansion
Laterally the scaphoid and trapezium, medially the pisiform and hook of hamate
Expansion
- Lateral (radial) side - tubercle of the scaphoid and tubercle of the trapezium
- Medial (ulnar) side - pisiform and hook of the hamate
These are the same “SLTP–TTCH” carpal bones you can feel at the base of the palm, and they bridge to form the carpal tunnel beneath the retinaculum.