Extensor Pollicis Longus, Posterior View

Description

Arising from the posterior forearm, the extensor pollicis longus muscle is followed distally as its tendon courses obliquely toward the thumb, passing from a more ulnar position to a dorsal, radial insertion on the base of the distal phalanx. From this posterior perspective, the tendon’s path across the dorsum of the wrist relates to the extensor retinaculum and the dorsal compartments, lying deep to superficial fascia and adjacent to the extensor pollicis brevis and abductor pollicis longus tendons at the radial side. The extensor expansion over the thumb and the dorsal surfaces of the metacarpals and phalanges provide bony landmarks for orientation. Nerve and vessel trajectories along the dorsoradial hand, including the superficial branch of the radial nerve and dorsal venous network, logically frame the surgical field. Clear depiction of the extensor pollicis longus is clinically tied to both function and failure. Rupture of this tendon after distal radius fracture or following dorsal wrist surgery produces loss of interphalangeal extension of the thumb, often with preserved metacarpophalangeal extension via extensor pollicis brevis. This view also supports teaching the anatomy of de Quervain region biomechanics by contrasting the first dorsal compartment tendons with the extensor pollicis longus crossing toward the third compartment at Lister’s tubercle. A tight space. Adhesions and tenosynovitis change glide mechanics. Use this artwork in upper limb anatomy courses, hand therapy curricula, and operative atlases covering dorsal wrist approaches, tendon transfers (for example, extensor indicis proprius to extensor pollicis longus), and post-traumatic tendon evaluation. It also suits radiology teaching sets that correlate surface anatomy with ultrasound or MRI of the dorsal compartments and thumb extensor tendons. Anatomical accuracy verified by SciePro's Medical Advisory Board.