The ankle has two major functions: support, propulsion

The ankle is formed by the distal tibia and fibula and the proximal talus

Forms three anatomical joints

1. Tibiofibular

1a. Syndesmosis joint

1aa. Bound by anterior & posteior tibiofibular ligaments

2. Talotibular

3. Talofibular

3a. Form a hinge joint (talocrural)

Distal tibia

1. Lateral aspect has: an articular surface for the fibula

2. Medial aspect ends with: a projecting mass called the medial malleolus

3. Mid portion has articular surface for talus

Distal fibula

1. Medial aspect has an articular surface for the tibia

2. Lateral aspect ends with a projecting mass called the lateral malleolus

Lateral malleolu is longer than medial malleolus

Proximal body of the talus

Also known as dome or trochlea

Articulates with the tibia superiorly and medially

Articulares with the fibula laterally

Anterior portion is wider than posterior portion

1. Tighter fit with dorsiflexion

The lateral ridge is slightly larger than the medial ridge

1. Talus rotates laterally with dorsiflexion

All three joints are encapsulated in a joint capsule

1. Thickest on the medial aspect

2. Extremely thin on the posterior aspect

Medial aspect

1. Deltoid ligament

1a. Calcaneotibular

1b. Anterior tibiotalar

1c. Tibionavicular

1d. Posterior tibiotalar

Lateral aspect

Lateral collateral ligament

1. Calcaneofibular

1a. Anterior talofibular

1b. Posterior talofibular

Sagittal plane

1. Plantarflexion/Dorsiflexion

2. However, the malleoli form a slightly oblique axis of rotation

Major functions include

1. Support

2. Adaptation to uneven terrain

3. Shock absorption

The foot is formed by 26 bones

1. Talus, Calcaneus, Navicular, Cuboid, Cuneiforms (1st(medial), 2nd(intermediate), 3rd(lateral)

2. Metatarsals (5)

3. Phalanges (14)

Form numerous joints

1. Subtalar

2. Midtarsal

2a. Chopart's joint

3. Tarsometatarsal joint

3a. Lisfrank's joint

4. Intermetatarsal

5. Metatarsophalangeal

6. Interphalangeal

Superior aspect

1. Inferior (plantar surface of the body of the talus)

Inferior aspect

1. Superior surface of the calcaneous & sustentaculum tali

Ligamentous support

1. Four talocalcaneal ligaments

1a. Posterior

1b. Medial

1c. Dorsal

1d. Lateral

Plantar calcaneonavicular (spring)

Midtarsal

1. Calcaneocuboid joint

2. Talnavicular joint

2a. These combine to form the Chopart's Joint

Short & long plantar ligament on plantar surface

Various ligaments on dorsal surface

Tarsometatarsal

1. First cuneiform with 1st metatarsal

2. Second cuneiform with 2nd metatarsal

3. Third cuneiform with 3rd metatarsal

4. Cuboid with 4th and 5th metatarsal

5. (These combine to form the Lisfranc's joint)

5a. Slightly longer 2nd metatarsal inserts into the depression formed by the slightly smaller intermediate cuneiform

5b. Supported by the dorsal and plantar ligaments

Intermetatarsal

1. Interaction between bases and heads of neighboring metatarsals

Metatarsophalangeal

1. Proximal - distal end of metatarsal

2. Distal - base of proximal phalange

Interphalangeal

1. Proximal - head (distal end) of proximal or intermediate

2. Distal - base (proximal end) of intermediate or distal phalange

Talocrural

1. Hinge joint

1a. Plantarflexion/Dorsiflexion

1b. Slightly oblique angle

Subtalar

1. mitered hinge

1a. Axis of rotation is debatable

1b. Can undergo movement in all three planes

1c. Inversion/Eversion

Talonavicular

1. Ball-and-socket

2. Inversion/Eversion

3. Significant contribution to plantar flexion/dorsiflexion

Calcaneocuboid

1. Saddle Joint

2. Significant Contribution to plantarflexion/dorsiflexion

Together, the talonavicular and calneocuboid form: the transverse tarsul or chopart's joint

There is little motion (gliding) between the cuboid, the three cuneiforms and the base of the 5 metatarsals

The interlocking fit of these bones help to form an arch

The arch is further strengthend by the recession of the base of the 2nd metatarsal into the midfoot with the middle (2nd) cuneiform

Metatarsophalangeal joints are condyloid that provide movement in two planes

1. Flexion/Extension/Hyperextension

2. Abduction/Adduction

Interphalangeal joints are hinge that only allow movement in one plane

1. Flexion/Extension

The tarsals and the metatarsals of the foot form 3 arches

The longitudinal arches

1. Lateral: Calcaneus, cuboid, and fourth and fifth metatarsals

2. MedialL: Calcaneus, talus, navicular, cuneiforms, and first three metatarsals

Transverse arch is formed by the base of the metatarsal bones with the cuboid and three cuneiforms

Plantarfascia and ligaments help support the arches

Individuals can be classified according to the height of their medial arch

Pes cavus - high arch

Pes planus - flat footed

Rigid or flexible

The configuration of the arch along with the tensile properties of the plantar fascia and ligaments form a

With normal foot alignment, the metatarsal heads should be perpendicular to the heel

Forefoot valgus - medial side drops below the neutral plane

Forefoot varus - medial side rises above neutral plane

With normal foot alignment, the calcaneus is parallel to the tibia and the fibula

Rear foot valgus - calcaneus is everted

Rear foot varus - calcaneus is inverted

O: Outside surface of lateral condyle of the tibia

I: Dorsal surface of the first cuneiform and base of first metatarsal

O: Outside surface of lateral conydle of the tibia and head of fibula

I: Dorsal surface of the intermediate and distal phalanges for toes 2-5

O: Anterior surface of the middl 1/4 of the fibula

I: Base of the 1st distal phalange

O: Anterior lateral surface of the lower 1/3 of the fibula

I: Base of the 5th metatarsal

O: Posterior surface of the medial and lateral femoral epicondyles

I: Tuberosity of the calcaneous via the achilles tendon

O: Upper 1/3 of posterior shaft of fibula and middle 1/3 or medial border of the tibia

I: Tuberosity of the calcaneous via the achilles tendon

O: Middle 1/3 of the posterior lateral surface of the tibia and middle 1/3 of the posterior medial surface of the fibula

I: Plantar surface of the navicular, first cuneiform, cuboid and junction of the 2nd cuneiform, 3rd cuneiform, second and third metatarsals

O:Posterior surface of the middle 1/3 of the tibia

I: Plantar surface of the base of the distal phalanges for toes 2-5

O: Posterior surface of the lower 2/3 of tibia

I: Plantar surface of the base of the 1st distal phalange

O: Lower lateral 2/3 of fibula

I: Base of the 5th metatarsal

O: Lateral surface of head and upper lateral 2/3 of fibula

I: Plantar surface of the 1st cuneiform and base of 1st metatarsal

Plantar flexion - Gastroc, soleus and peroneus longus. (Assistance from tibialis posterior, peroneus brevis, flexor digitorum longus and flexor hallucis longus)

Dorsiflexion - Tibialis anterior, peroneus tertius, extensor digitorum longus and extensor hallucis longus

Inversion - Tibialis anterior, tibialis posterior, flexor digitorum longus and flexor hallucis longus

(Assistance from extensor hallucis longus)

Eversion - Peroneous tertius, peroneous longus, peroneous brevis and extensor digitorum longus

Toe flexion - Flexor digitorum longus and flexor hallucis longus

Toe extension - extensor digitorum longus and extensor hallucis longus

High ankle sprain

1. Sprain of the syndesmosis joint (distal tibiofibular joint)

2. Sprain of the ligaments that hold the tibia and fibula together

Compression fracture of the calcaneus

1. Lower's fracture or Don Jaun's Fracture

Most commonly caused by a fall from heights