Flexor Hallucis Longus Tendon Beneath The Skin, Plantar View

Description

Seen from the plantar aspect beneath the skin, the flexor hallucis longus tendon forms a thick, white cord coursing anteromedially toward the hallux, deep to the plantar aponeurosis and the first-layer muscles. Medially, abductor hallucis borders the tendon’s proximal course, while flexor digitorum brevis lies more centrally and superficially over the midfoot, with abductor digiti minimi defining the lateral margin of the sole. Distally, the tendon continues toward the base of the distal phalanx of the great toe, passing plantar to the first metatarsophalangeal region as it approaches its insertion. A superficial plantar vein is included in blue, reinforcing the subcutaneous plane. Plantar visualization of the flexor hallucis longus tendon matters because this structure is a primary driver of hallux interphalangeal flexion and a stabilizer during push-off, and its gliding interface is a common pain generator in dancers and runners. Along its plantar course, the tendon typically intersects the flexor digitorum longus at the knot of Henry, a key landmark when tracing tenosynovitis, adhesions, or partial tears that can present as trigger hallux or plantar medial midfoot pain. This is a hard tendon to palpate well. The layered context also supports teaching the relationship between superficial intrinsic muscles and the deeper long flexor tendons that are targeted during plantar surgical exposures and guided injections. Use this artwork for foot and ankle anatomy teaching in gross anatomy, podiatry, physiotherapy, and sports medicine curricula, or for publications covering flexor hallucis longus tendinopathy, tendon transfer planning, or plantar approach orientation during operative notes and patient education. Anatomical accuracy verified by SciePro's Medical Advisory Board.