The Flexor Digitorum Longus Tendon of a Human Male Viewed from the Plantar

Description

Arising from the posterior compartment of the leg, the flexor digitorum longus tendon passes posterior to the medial malleolus and enters the plantar foot deep to the flexor retinaculum, then courses anteriorly along the medial plantar aspect toward the midfoot. Distal to the tarsal tunnel it crosses the flexor hallucis longus tendon at the chiasma plantare (knot of Henry), then runs centrally over the tarsals and metatarsals before dividing into four digital slips for toes II through V. Each slip continues distally to the plantar surfaces of the middle and distal phalanges, deep to the metatarsophalangeal joints and aligned with the interphalangeal joints, with the skeletal landmarks and articular cartilage planes providing clear spatial context. Bony detail includes the calcaneus and talus proximally, the midfoot tarsals, metatarsal shafts, and phalangeal segments. Function drives the anatomy here: flexor digitorum longus produces toe flexion and assists the windlass mechanism by tensioning the plantar structures during push-off, so its line of pull relative to the metatarsals and phalanges matters when teaching gait mechanics. The tendon’s passage through the tarsal tunnel explains why posterior tibial tendon dysfunction and tibial nerve irritation are evaluated in the same region, and why injections or endoscopic approaches near the medial malleolus demand careful respect for adjacent tendons within their synovial sheaths. A key landmark. The depiction of a wedge-shaped bony cut also supports discussion of corrective osteotomy planning in forefoot or midfoot deformity, where altered alignment changes tendon moment arms and postoperative toe purchase. Ideal for lower limb anatomy lectures, podiatry and orthopedic teaching files, and surgical atlas figures discussing plantar tendon layering, the knot of Henry, and digital flexor mechanics at the metatarsophalangeal and interphalangeal joints. It also supports exam prep diagrams that pair plantar tendon courses with tarsal tunnel clinical anatomy. Anatomical accuracy verified by SciePro's Medical Advisory Board.