Leg - Posterior
Primary actions of the posterior compartment muscles are:
- Foot plantar flexion.
- Leg flexion
Posterior knee:
- Originates on the lateral femoral condyle and the popliteal ligament
- Inserts on the proximal tibia;
- It flexes and medially rotates the leg,
Superficial leg (from deep to superficial):
- Originates on proximal head of the fibula and the soleal line of the tibia
- Inserts on the calcaneus via calcaneal tendon
- Plantar flexes the foot.
- Originates on lateral and medial femoral condyles
- Inserts on calcaneus via calcaneal tendon
- Plantar flexes the foot and flexes the knee.
- Gastrocnemius joins soleus to form the calcaneal tendon (aka the "Achilles' tendon," aka the "triceps surae") where they insert on the calcaneus.
Deep leg (from lateral to medial):
- Originates on the distal 2/3rds of the fibula and interosseous membrane
- Inserts on the base of the distal phalanx of digit 1
- It plantar flexes the foot and flexes the distal phalanx of digit 1.
- Originates on the proximal tibia, fibula, and interosseous membrane
- Inserts primarily at the navicular tuberosity and medial cuneiform
- It plantar flexes and inverts the foot.
- Tibialis posterior is the deepest muscle of the posterior compartment; it lies directly against the posterior tibia.
- Originates on the middle tibial shaft
- Inserts on the distal phalanges of digits 2-5
- It flexes the corresponding toes and plantar flexes the foot.
Primary actions of the posterior compartment muscles are:
- Foot plantar flexion.
- Leg flexion
- The tendons of the deep muscles of the posterior lower leg cross at the ankle.
- From medial to lateral at the ankle, their order is: