Pronator Quadratus, Anterior View

Description

Across the distal anterior forearm, the pronator quadratus is highlighted as a flat, quadrilateral muscle spanning from the anteromedial distal ulna to the anterolateral distal radius, lying deep to the flexor tendons near the wrist. Proximal to it, the radius remains lateral and the ulna medial in anatomical position, with their shafts leading distally toward the radiocarpal region. The carpal bones, metacarpals, and phalanges are included distally to establish continuity from forearm to hand. Small but telling. Because pronator quadratus is the primary pronator in neutral and during resisted pronation, this anterior depiction aligns well with common clinical testing and with anatomic explanations of pronation at the distal radioulnar joint rather than at the elbow. Distal radius fracture fixation and volar plating often require working in the same compartment, where the muscle is elevated from the radius to expose the volar surface while protecting adjacent structures such as the volar radiocarpal ligaments and the path of the median nerve more proximally. Its relationship to the radius and ulna also helps clarify how loss of pronation can follow distal forearm trauma or scarring in the volar deep plane. Use this artwork for upper limb anatomy teaching in medical and physiotherapy curricula when discussing pronation-supination mechanics, distal radioulnar joint kinematics, and deep volar forearm layering. It also fits operative technique manuals and orthopedic hand and wrist chapters that describe the volar (Henry) approach and pronator quadratus repair after distal radius internal fixation. Anatomical accuracy verified by SciePro's Medical Advisory Board.