Ankle/Foot Biomechanics

What is the ligamentous support of the distal tibiofibular joint?

Anterior/posterior tibiofibular ligaments

Interosseous membrane

What is the closed pack position of the distal tibiofibular joint?

Max dorsiflexion

What is the closed pack position of the talocrural joint?

Max DF

What are the convex and concave surfaces of the subtalar joint?

Convex: talus

Concave: calcaneus

Open packed position of the subtalar joint?

Midway between pronation and supination (subtalar neutral)

What are the 3 movements that make up ankle supination and pronation?

• Supination: PF, adduction, and inversion

• Pronation: DF, abduction, eversion

What are the collateral ligaments of the lateral ankle?

Ant/post talofibular ligament

Calcaneofibular ligament

What muscles does the superficial peroneal nerve innervate?

Fibularis longus and brevis (aka peroneus)

What muscles does the deep peroneal nerve innvervate?

Anterior tibialis

Peroneus tertius

EHL and EHB

EDL and EDB

What muscles does the tibial nerve innervate?

Gastroc

Soleus

FHL

FDL

Tibialis posterior

Explain the position of the LE during ankle pronation.

Explain the position of the LE during ankle supination.

What are the Ottawa Ankle Rules?

• Bony tenderness along the distal 6cm of medial malleolus

• Bony tenderness along the distal 6cm of lateral malleolus

• Inability to bear weight both immediately and in ED

OR

• Bony tenderness at the base of the 5th metatarsal

• Bony tenderness at the navicular bone

• Inability to bear weight both immediately and in ED

If 3 of either category is the case, X-Rays are required