KnotesFree Orthopaedic & FRCS notes, viva stations and higher order SBAs

Forearm cross section

High YieldHand & WristthinKbox SBA

Compartments

The forearm has flexor-pronator and extensor-supinator groups separated by the radius, ulna and interosseous membrane.

Volar aspect

  • Superficial flexors
  • Intermediate layer: FDS
  • Deep layer: FDP, FPL, pronator quadratus

Dorsal aspect

  • Wrist and finger extensors
  • Abductor pollicis longus and extensor compartments around the wrist

Neurovascular anatomy

  • Median nerve in the volar compartment
  • Ulnar nerve and artery medially
  • Radial nerve divides into superficial sensory and posterior interosseous branches

Clinical relevance

  • Compartment syndrome
  • Surgical approaches to radius and ulna
  • Tendon transfer planning

Diagram

Forearm cross section

Written/reviewed by Kishore Puthezhath

Professor of Orthopaedics and Consultant Paediatric Orthopaedic Surgeon

FRCS (Tr & Orth) revision resource

Reviewed: September 2026