Corpus: Flexor digitorum longus muscle
1. Definition
The flexor digitorum longus muscle is a skeletal muscle of the lower leg. It is part of the deep calf muscles.
2. Course
The flexor digitorum longus muscle originates from the posterior surface and the medial aspect of the tibia.
The tendon of the flexor digitorum longus muscle crosses over the tendon of the tibialis posterior muscle, forming the so-called crural chiasm. Further distally, in the region of the sole of the foot, it crosses over the tendon of the flexor hallucis longus muscle, forming the so-called plantar chiasm.
The tendon of the flexor digitorum longus muscle then attaches to the distal phalanges of toes II-V and serves as the origin of the lumbrical muscles of the foot.
3. Innervation
The flexor digitorum longus muscle is innervated by the tibial nerve, with fibers from segments S1 and S2.
4. Function
The flexor digitorum longus muscle facilitates the flexion of the toes and plantar flexion of the foot. It also plays a role in the supination of the foot.