Ankle and Foot Kinesiology Overview

Stability

A function of the foot that provides support and balance.

Mobility

A function of the foot that allows for movement and flexibility.

Protection

A function of the foot that safeguards against injury.

Rigid lever for walking

The foot acts as a stiff structure to assist in locomotion.

Absorbs shock

The foot mitigates impact forces during activities such as walking or running.

Sensation of sole

The foot provides sensory feedback from the ground.

Base for weight bearing

The foot supports the body's weight during standing and movement.

Propels body forward

The foot aids in advancing the body during locomotion.

Prevent injury

The foot's structure and function help to reduce the risk of harm.

Bones of the Foot

The foot consists of 26 bones plus 2 sesamoids.

Forefoot

Contains 5 Metatarsals and 14 Phalanges.

Midfoot

Contains Navicular, Cuboid, and 3 Cuneiforms.

Hindfoot

Contains Talus and Calcaneus.

Talocrural joint

A hinge joint that allows dorsiflexion and plantarflexion.

Subtalar joint

Allows inversion and eversion, important for adapting to uneven surfaces.

Transverse Tarsal Joint

Adds flexibility and transitions between hindfoot and forefoot.

Dorsiflexion

Movement of the foot upwards, with a range of motion of 0-20°.

Plantarflexion

Movement of the foot downwards, with a range of motion of 0-50°.

Open-Packed Position (OPP)

Position of the ankle at 10° plantarflexion.

Closed-Packed Position (CPP)

Position of the ankle at full dorsiflexion.

Capsular Pattern (CP)

Pattern of restriction where plantarflexion is greater than dorsiflexion.

Enthesitis

Inflammation of tendon attachment.

Anterior Compartment

Dorsiflexion; Muscles: TA, EHL, EDL, PT

Lateral Compartment

Pronation; Muscles: PL, PB

Posterior Compartment

Plantarflexion; Muscles: GS, Soleus, TP, FHL, FDL

Medial Compartment

Supination; Muscles: TP, FHL, FDL

Dorsiflexors

Muscles in the anterior compartment responsible for dorsiflexion.

Tibialis Anterior

Dorsiflexion, Inversion; Origin: Medial cuneiform & base of 1st MT; Insertion: Lateral condyle & lateral surface of tibia; Nerve: Deep Fibular.

EHL

Dorsiflexion, Extends hallux; Origin: Middle anterior fibula; Insertion: Distal phalanx of big toe; Nerve: Deep Fibular.

EDL

Dorsiflexion, Extends toes 2-5; Origin: Lateral condyle of tibia, anterior fibula; Insertion: Distal phalanges 2-5; Nerve: Deep Fibular.

Peroneus Tertius

Dorsiflexion, Eversion; Origin: Distal anterior fibula.

Plantarflexors

Muscles in the posterior compartment responsible for plantarflexion.

Gastrocnemius

Plantarflexion, Knee flexion; Origin: Femoral condyles; Insertion: Calcaneus via Achilles tendon; Nerve: Tibial.

Soleus

Plantarflexion; Origin: Posterior fibula & tibia; Insertion: Calcaneus via Achilles tendon; Nerve: Tibial.

Plantaris

Weak plantarflexion; Origin: Lateral supracondylar line (femur); Nerve: Tibial.

Tibialis Posterior

Plantarflexion, Inversion; Origin: Posterior tibia/fibula; Insertion: Navicular, cuneiforms, 2-4 MTs; Nerve: Tibial.

FDL

Plantarflexion, Toe flexion; Origin: Posterior tibia; Insertion: Distal phalanges 2-5; Nerve: Tibial.

FHL

Plantarflexion, Big toe flexion; Origin: Posterior fibula; Insertion: Distal phalanx of big toe.

Evertors

Muscles in the lateral compartment responsible for eversion.

Peroneus Longus

Eversion, Plantarflexion; Origin: Head & upper fibula; Insertion: Base of 1st MT & medial cuneiform; Nerve: Superficial Fibular.

Peroneus Brevis

Eversion, Plantarflexion; Origin: Lower lateral fibula; Insertion: Base of 5th MT; Nerve: Superficial Fibular.

Invertors

Muscles that perform inversion.

Intrinsic Foot Muscles

Muscles located within the foot, divided into dorsal and plantar groups.

Extensor Digitorum Brevis

Extends toes 2-4; Nerve: Deep Fibular.

Abductor hallucis

Muscle in the plantar group; Nerve: Medial Plantar.

Lumbricals

Muscles in the plantar group; 1st = MP; 2-4 = LP; Nerve: Medial & Lateral Plantar.

Tricep Surae

Strongest plantar flexion; consists of Gastrocnemius and Soleus.

Mitered Joint

Two pieces cut at an angle (usually 45°) to form a corner, often used in frames and trims.

Mortise and Tenon Joint

A tongue-like tenon fits into a hole-like mortise, forming a strong right-angle joint.

Kinestia

Movement awareness.

Proprioception

Position awareness.

Talocrural joint

Refers to the talocrural (ankle) joint where the talus fits into the mortise of tibia & fibula.

Keystone of the medial longitudinal arch

Talus.

Subtalar joint motion

Primarily allows Inversion/Eversion.

Strongest inverter of the foot

Tibialis posterior.

Ligament supporting the medial longitudinal arch

Spring ligament (plantar calcaneonavicular).

Primary function of the plantar fascia

Maintain arch height.

Close-packed position of the talocrural joint

Full dorsiflexion.

Muscles forming the stirrup support of the foot

Tibialis anterior and fibularis longus.

Phase when the foot becomes rigid during gait

Terminal stance.

Axis of rotation for the talocrural joint

Mediolateral.

Muscle assisting with both plantarflexion and knee flexion

Gastrocnemius.

Joint contributing most to foot supination and pronation

Subtalar.

Muscle supporting the transverse arch of the foot

Adductor hallucis (transverse head).

Muscle that dorsiflexes the ankle and inverts the foot

Tibialis anterior.

Nerve innervating the intrinsic foot muscles (except EDB/EHB)

Tibial nerve (via medial and lateral plantar branches).

Role of the fibularis longus during stance phase

Evert the foot and support lateral arch.

Muscle with a pulley around the lateral malleolus

Fibularis longus.

Weight-bearing axis of the leg passes through which bone

Talus.

Ligament preventing excessive eversion of the foot

Deltoid ligament.

Structure at greatest risk during an inversion sprain

Not provided.

Deltoid ligament

A ligament that is at risk during an inversion sprain.

Anterior talofibular ligament

The structure at greatest risk during an inversion sprain.

Cuboid

The bone that does NOT articulate with the navicular.

Quadratus plantae

A muscle that assists FDL by redirecting pull.

Subtalar joint movement

Best described by the oblique axis.

2nd metatarsal

The most common site of foot stress fractures.

Tarsal tunnel

Contains the tibial nerve.

Calcaneocuboid joint

Forms the transverse tarsal joint along with the talonavicular joint.

Deep fibular nerve

The nerve damaged in a patient with foot drop.

Dorsal interossei

The main action is to abduct toes.

Calcaneus

Transmits body weight to the ground via the heel (posterior tuberosity).

Soleus

The muscle that lies immediately deep to the gastrocnemius.

Plantaris

Not part of the triceps surae.