Structure & Function

of the Ankle and Foot

A complicated model of simplicity that you really think little about

until you have a problem with one.

The Foot and Ankle

The foot and ankle must be

able to instantly adapt to the

surface that you are walking

on so that you can get, “from

point A to point B.”

Acts as shock absorber

as heel hits the ground

Adapts to level and

unlevel surfaces

Provides stable base of

support

The Foot and Ankle

Terminology

-Plantar flexion

-Dorsi flexion

-Inversion

-Eversion

--Supination:

plantarflexion & inversion

--Pronation:

dorsiflexion & eversion

Distal Tibia and Fibula

The Foot and Ankle: Osteology

The Foot and Ankle:

Arthrology & Osteology

tibia

talus

navicular

calcaneus

fibula

lateral malleolus

Joints at the foot and ankle

• Talocrural (tibiotalar): Talus and tib/fib

–Allows dorsi and plantarflexion

• Subtalar: Talus and calcaneus

–Allows inversion and eversion

• Transverse tarsal: Talonavicular and Calcaneocuboid joints

–Allows bi-planar motions

–Supination/Pronation

• Metatarsophalangeal: Metatarsal heads and proximal phalanges

–Flex/ext and abd/add

• Interphalangeal: toes 2-5 have PIP and DIP; 1st toe only has an IP (just like thumb)

–Flex/ext only

Ligaments that support the foot & ankle

Why do you think

that there are so

many of them?

Ligaments of ankle/foot

• Lateral Collateral ligaments

–Located on the lateral ankle

–Resists inversion

•Anterior Talofibular**

• Posterior Talofibular

•Calcaneofibular

• Deltoid ligament

–Located on medial ankle

–Resists eversion

•Tibionavicular

•Tibiocalcaneal

•Tibiotalar

• Anterior/Posterior Tibiofibular ligaments

–Binds distal tib-fib joint (stability)

• Superior to other ligaments (high-ankle sprain)

Inversion sprain High ankle sprain

The Foot and Ankle

Eversion sprain

Medial Longitudinal Arch

• Primary shock absorber

in the foot

• Maintained by ligaments,

joints, plantar fascia

• Decreased arch = pes

planus

• Increase arch = pes

cavus