Posterior Leg and Ankle Joint

• Posterior Aspect of Leg Bones

  
• Muscles of the Posterior Compartment

  •7 muscles

  –3 superficial; 4 deep

  •Superficial muscles all insert on posterior surface of calcaneous via Tendocalcaneous

  •Tendons of deep muscles pass behind medial malleolus to plantar surface of foot (except popliteus)

  
• Superficial Muscles - Gastrocnemius

  Medial Head:

  Popliteal surface of femur sup. to medial condyle

  Lateral Head:

  Lateral aspect of lateral condyle of femur

  Tibial nerve (S1, 2)

  Plantarflexes ankle; Flexes knee

  
• Superficial Muscles - Plantaris

  Lateral supracondylar line of femur (proximal to lateral head of gastrocnemius)

  Tibial nerve (S1, 2)

  Assists Plantarflexion of ankle

  
• Superficial Muscles - Soleus

  Soleal line of tibia

  Upper ⅓ posterior fibula

  Tendinous arch between bony attachments

  Tibial nerve (S1, 2)

  Plantarflexes ankle joint

  
• Deep Muscles - Popliteus

  Lateral condyle of femur

  (Pit for popliteus) and lateral meniscus

  →Popliteal area of tibia

  (above soleal line)

  Tibial n. (L4, 5, S1)

  Unlocks knee joint by laterally rotating femur on fixed tibia

  
• Deep Muscles – Flexor Digitorum Longus

  Posterior Surface of Tibia

  →Base of distal Phalanx of digits 2-5

  Tibial nerve (L5, S1, 2)

  Flexes lateral 4 digits

  Weak plantarflexor of ankle

  
• Deep Muscles – Flexor Hallucis Longus

  Posterior surface of fibula

  →Base of distal phalanx of hallux

  Tibial nerve (L5, S1, 2)

  Flexes hallux

  Weak plantarflexor of ankle

  
• Deep Muscles – Tibialis Posterior

  Posterior surface of tibia and fibula, interosseous membrane

  →Tuberosity of navicular, cuneiforms, cuboid, sustentaculum tali of calcaneus, base of 2nd, 3rd, and 4th metatarsals

  Tibial nerve (L4, 5)

  Plantarflexes ankle

  Inverts foot

  
• Tendons of Deep Muscles

  Tibialis posterior tendon passes deep to flexor digitorum longus

  Groove posterior to the medial malleolus

  Flexor hallucis longus grooves the posterior surface of the lower end of the tibia and the posterior surface of the talus

  Medial to lateral arrangement of tendons at ankle joint: Tibialis Posterior, Flexor Digitorum Longus and Flexor Hallucis Longus

  (Tom, Dick and Harry)

  
• Flexor Retinaculum

  Medial Malleolus

  → Calcaneous

  Posterior tibial vessels and tibial nerve found between FDL and FHL tendons

  
• Arteries of Posterior Leg

  Posterior Tibial Artery: terminal branch of popliteal artery

  Between heads of gastrocnemius and deep to soleus to run on surface of TP and FDL

  •Gives Fibular artery as a branch

  •Terminates as Medial and Lateral Plantar arteries in the foot

  Fibular artery: runs medial to fibula, usually within FHL

  
• Nerves of the Leg

  
• Tibial nerve

  •Passes between the heads of gastrocnemius and deep to tendinous arch of soleus, with posterior tibial a.

  •Between FHL and FDL at the ankle jt.

  •Gives terminal branches that supply the sole of the foot: Medial and Lateral Plantar nerves

  
• Cutaneous Innervation

  
• Inferior tibiofibular joint

  Syndesmosis

  Interosseous tibiofibular ligament continuous with interosseous membrane

  Anterior and posterior ligaments

  Slight movement to accommodate wedging of trochlea of talus during dorsiflexion

  
• Ankle Joint

  Distal ends of Tibia and Fibula form: Malleolar Mortise

  Malleolar Mortise articulates with: Trochlea of the Talus

  
• Ankle Joint

  
• Range of Motion

  Dorsiflexion

  20-30º

  Plantarflexion

  30-50º

  
• Capsule and Ligaments

  Attaches around articular margins

  Anteriorly extends onto the neck of talus

  Weak anteriorly and posteriorly

  Supported laterally and medially by strong Collateral Ligaments

  Anterior and posterior views with weak parts of capsule removed

  
• Lateral Collateral Ligaments

  Anterior Talofibular → neck of talus

  Posterior Talofibular → lateral tubercle of talus

  Calcaneofibular → lateral surface of calcaneous

  
• Medial Collateral Ligament (Deltoid)

  Fans out from medial malleolus and has 4 parts:

  1. Anterior Tibiotalar

  2) Tibionavicular

  3) Tibiocalcaneal

  4) Posterior Tibiotalar

  
• Collateral Ligaments

  
• Relations of Ankle Joint