Deep Muscles of the Posterior Compartment

• Popliteus
  • Bony Attachments:
    • 1. Lateral surface of lateral condyle of femur and lateral meniscus
    • 2. Posterior surface of tibia (superior to soleal line)
  • Innervation: Tibial nerve (L4, L5, & S1)
  • Arterial Supply: Posterior tibial artery, popliteal artery
  • Action: Weak flexor of knee, unlocks knee by rotating tibia (medially)
• Flexor Hallucis Longus
  • Bony Attachments:
    • 1. Posterior inferior surface of fibula and interosseous membrane
    • 2. Base of distal phalanx of great toe (hallux)
  • Innervation: Tibial nerve (S2 & S3)
  • Arterial Supply: Fibular artery/Peroneal artery
  • Action: Flexes great toe and plantarflexes foot (supports medial longitudinal arch)
• Flexor Digitorum Longus
  • Bony Attachments:
    • 1. Medial posterior surface of tibia (inferior to soleal line)
    • 2. Base of distal phalanges 2-5
  • Innervation: Tibial nerve (S2 & S3)
  • Arterial Supply: Posterior tibial artery
  • Action: Flexes toes 2-5 (supports longitudinal arch)
• Tibialis Posterior
  • Bony Attachments:
    • 1. Posterior surface of fibula & tibia, interosseous membrane
    • 2. Tuberosity of navicular, cuboid, 2nd cuneiform, and bases of 2-4th metatarsals
  • Innervation: Tibial nerve (L4 & L5)
  • Arterial Supply: Posterior tibial artery, peroneal (fibular) artery
  • Action: Plantarflexes foot & inverts foot