Muscles of the Leg (Images)
Key actions of the anterior and lateral compartment muscles:
- Dorsiflexion
- pull the dorsal surface (aka, top) of your foot towards the anterior leg to demonstrate this action.
- Plantar flexion
- push the ventral surface (aka, sole) of your foot towards the posterior leg to demonstrate this action.
- Eversion
- turn the ventral surface of your foot to face laterally to demonstrate this action.
- Inversion
- turn the ventral surface of your foot to face medially (towards the midline of the body) to demonstrate this action.
Key actions of the posterior compartment muscles:
- Foot plantar flexion.
- Leg flexion
Tibialis anterior
- Originates on the lateral tibial condyle and the interosseous membrane
- Inserts on the first cuneiform and first metatarsal
- Dorsiflexes and inverts the foot.
Extensor hallucis longus:
- Originates on the middle of the anterior fibula and interosseous membrane
- Inserts on the base of the distal phalanx of digit 1
- Extends the big toe and dorsiflexes and inverts the foot.
Extensor digitorum longus:
- Originates on the lateral tibial condyle, the interosseous membrane, and, the proximal 2/3rds of the fibula
- Inserts on the bases of the middle and distal phalanges of digits 2-5
- Extends the toes and dorsiflexes and everts the foot.
Fibularis tertius:
- Originates on distal fibula and interosseous membrane
- Inserts on the base of the 5th metatarsal.
- Dorsiflexes and everts the foot.
Fibularis longus:
- Originates on the lateral tibial condyle, head and proximal lateral fibula, and wraps under the foot
- Inserts on the base of the first metatarsal and medial cuneiform
- Everts and plantar flexes the foot.
Fibularis brevis:
- Originates on the distal lateral fibula (and intermuscular septa)
- Inserts on the base of the fifth metatarsal
- Everts and plantar flexes the foot.
Popliteus
Superficial Layer
Gastrocnemius
Soleus
Deep Layer:
Flexor hallucis longus
Tibialis posterior
Flexor digitorum longus
Mnemonic for deep muscles:
Above the ankle, from lateral to medial
- Have a Terrific Day (Have = Hallucis; Terrific = Tibialis; Day = Digitorum)
- Tom, Dick, and Harry (Tom = Tibialis; Dick = Digitorum; Harry = Hallucis)
Bones of the Leg and Foot