Ankle Joint: Anatomy

The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot. The subtalar joint and the other tarsal bones create many synergistic articulations, allowing for a wide range of motion (ROM)—plantar flexion, dorsiflexion, eversion, inversion, abduction, and adduction. The movements are generated by large muscle groups that originate in the leg and insert as well as act upon the bones of the foot and tarsus.

Last updated: 9 Mar, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Bones of the Ankle

Ankle joint

Radiograph of the ankle showing the normal anatomy of the ankle and the relationship Relationship A connection, association, or involvement between 2 or more parties. Clinician–Patient Relationship of the bones and joints

Image by Lecturio.
  • Distal tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy
    • Together with the distal fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy, they form a rectangular mortise (socket) in which the trochlea Trochlea Arm: Anatomy of the talus sits.
    • Medial malleolus
      • Distal extension Extension Examination of the Upper Limbs of the tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy 
      • Provides medial support
      • Tibial plafond: the distal articular surface of the tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy
  • Distal fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy
    • Together with the distal tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy, they form a rectangular mortise (socket) in which the talus sits.
    • Lateral malleolus
  • Talus
    • The 2nd-largest tarsal bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types
    • Has a wedge-like shape
    • The majority of the talar surface is covered with articular cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology.
    • No tendons or muscles insert into or originate from the talus.
    • Articulates with the tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy, fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy, navicular Navicular Foot: Anatomy, and calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy bones

Joints of the Ankle

The tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy, fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy, and talus form the ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot. and, along with the subtalar and talar joints, contribute to the coordinated movement of the ankle.

Lateral view of the ankle

Lateral view of the ankle: Note the 4 different articulations that work synergistically to achieve the full range of motion Range of motion The distance and direction to which a bone joint can be extended. Range of motion is a function of the condition of the joints, muscles, and connective tissues involved. Joint flexibility can be improved through appropriate muscle strength exercises. Examination of the Upper Limbs of the ankle.

Image by Lecturio.

Distal tibiofibular

  • Type: fibrous Fibrous Fibrocystic Change syndesmosis
  • Components:
    • Medial side of the distal end of fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy
    • Lateral side of the distal end of tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy
  • Supporting ligaments:
    • Anterior and posterior inferior tibiofibular ligaments
    • Transverse ligament
    • Interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy
  • Function: 
    • Stability
    • Weight-bearing
    • Minimal movement

Talocrural (true ankle) joint

Subtalar (talocalcaneal) joint

  • Type: synovial joint Synovial joint Jaw and Temporomandibular Joint: Anatomy
  • Components: 
    • Anterior, posterior, and middle talocalcaneal joints
    • Composed of 3 alternating convex–concave areas on each of the talus and calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy bones
  • Supporting ligaments:
    • Interosseous talocalcaneal ligament
    • Anterior, posterior, lateral, and medial talocalcaneal ligaments
  • Function:

Transverse tarsal (midtarsal) joint

  • Type:
    • The talocalcaneonavicular joint is a modified ball-and-socket joint.
    • The calcaneocuboid joint is a modified saddle-type joint.
  • Components:
    • Talocalcaneonavicular joint: 
      • Head of the talus
      • Concavity formed by the posterior area of the navicular Navicular Foot: Anatomy and anterior area of the calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy 
    • Calcaneocuboid joint: 
      • Distal surface of the calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy 
      • Proximal area of the cuboid Cuboid Foot: Anatomy
  • Supporting ligaments:
  • Function:
    • The talocalcaneonavicular joint performs inversion and eversion Eversion Chronic Apophyseal Injury of the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy.
    • The calcaneocuboid joint performs gliding and rotational movements between the calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy and cuboid Cuboid Foot: Anatomy.

Ligaments and Retinacula

Several major ligament complexes exist in the ankle to provide stability and support.

Lateral ligament complex

  • Resists over-inversion of the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy
  • Extends from the lateral malleolus of the fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy
  • Consists of:
    • CFL 
      • Passes posteroinferiorly
      • Attaches to tip of lateral malleolus 
    • Anterior talofibular ligament (ATFL)
      • Extends anteromedially 
      • Attaches to lateral malleolus
      • Most commonly injured ligament 
      • Injured in inversion sprains
    • Posterior talofibular ligament (PTFL)
      • Attaches to malleolar fossa of fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy
      • Located medially, runs horizontally
      • Supports ankle in dorsiflexion
Lateral view of the ankle

Lateral view of the ankle featuring the supporting ligaments of the talocrural and subtalar joints

Image by Lecturio.

Medial or deltoid ligament

  • Stronger than the lateral complex 
  • Resists over-eversion of the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy
  • This ligament originates from the medial malleolus and then fans out in 4 distinct strands:
    • Tibiocalcaneal ligament
      • Courses inferiorly, almost vertically
      • Attaches to the posterior sustentaculum tali or talar shelf of the calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy, which is the horizontal eminence
    • Tibionavicular ligament
      • Courses anteriorly
      • Attaches to the tuberosity of the navicular Navicular Foot: Anatomy bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types
    • Anterior tibiotalar ligament
      • Short, thin ligament that courses anteriorly and inferiorly
      • Attaches to the medial talus and medial tubercle
      • Lies deeply to the tibionavicular and tibiospring ligaments
    • Posterior tibiotalar ligament 
      • Courses posteriorly and inferiorly 
      • Attaches to the posteromedial surface of the talus bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types
Ankle joint medial view

Medial view of the ankle highlighting the various ligaments of the medial ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot.

Image by Lecturio.

Syndesmosis of the ankle

  • Responsible for the integrity of the ankle mortise
  • Consists of the following elements:
    • Interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy
    • Transverse ligament
    • Anterior and posterior inferior tibiofibular ligaments

Retinacula

  • A fibrous band Fibrous band Meckel’s Diverticulum that surrounds or covers and stabilizes tendons
  • Acts as a pulley system to allow a smooth gliding surface for the muscle tendons, which prevents tendon bowstringing
  • Anterior or extensor retinacula
    • Muscular tendons from the anterior compartment of the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy pass under this retinacula.
    • Superior extensor retinaculum: a transverse anterior band between fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy and tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy
    • Inferior extensor retinaculum: a transverse Y-shaped band that extends from the medial malleolus and plantar aponeurosis Plantar aponeurosis Foot: Anatomy laterally to the lateral surface of the calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types
  • Medial or flexor retinaculum
    • Formed by an oblique band that extends from the medial malleolus of the tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy to the medial surface of the calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types
    • Muscular tendons from the deep layer of the posterior compartment of the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy pass under this retinaculum.
    • Additionally, the posterior tibial vessels and tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy pass under it.
    • Forms the roof of the tarsal tunnel, with a narrow space on the medial side of the ankle through which various structures pass from the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy into the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy:
  • Lateral retinacula
    • The peroneal (fibular) tendons pass under the lateral retinacula.
    • Superior fibular or peroneal retinaculum: extends from the lateral malleolus to the calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy
    • Inferior fibular or peroneal retinaculum: a continuation of the inferior extensor retinaculum

Muscles of the Ankle and Range of Motion

Muscles

The muscles of the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy insert into the bones of the ankle to create movement, and the range of motion Range of motion The distance and direction to which a bone joint can be extended. Range of motion is a function of the condition of the joints, muscles, and connective tissues involved. Joint flexibility can be improved through appropriate muscle strength exercises. Examination of the Upper Limbs (ROM) occurs in cardinal planes.

Table: Anterior compartment
Muscle Origin Insertion Action Innervation
Tibialis anterior Tibialis anterior Leg: Anatomy
  • Lateral condyle
  • Upper tibial shaft
  • Interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy
Interior surface of medial cuneiform Dorsiflexion Deep fibular (peroneal) nerve
Extensor hallucis longus Extensor hallucis longus Leg: Anatomy
  • Anteromedial fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy shaft
  • Interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy
Distal phalanx big toe Dorsiflexion Deep fibular (peroneal) nerve
Extensor digitorum longus Extensor digitorum longus Leg: Anatomy
  • Lateral condyle of tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy
  • Proximal portion of fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy
  • Interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy
Middle and distal phalanges Phalanges Bones that make up the skeleton of the fingers, consisting of two for the thumb, and three for each of the other fingers. Hand: Anatomy 2–5 Dorsiflexion Deep fibular (peroneal) nerve
Table: Lateral compartment
Muscle Origin Insertion Action Innervation
Fibularis longus Upper portion of lateral fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy 1st metatarsal,
medial cuneiform
Plantar flexion Flexion Examination of the Upper Limbs,
eversion Eversion Chronic Apophyseal Injury
Superficial fibular
Fibularis brevis Distal fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy shaft Proximal end of 5th metatarsal Plantar flexion Flexion Examination of the Upper Limbs,
eversion Eversion Chronic Apophyseal Injury
Superficial fibular
Posterior compartment: Superficial muscles
Muscle Origin Insertion Action Innervation
Gastrocnemius Gastrocnemius Leg: Anatomy Medial and lateral condyles Posterior calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy Plantar flexion Flexion Examination of the Upper Limbs Tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy
Soleus Soleus Leg: Anatomy Superior tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy, fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy, interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy Posterior calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy Plantar flexion Flexion Examination of the Upper Limbs Tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy
Plantaris Plantaris Leg: Anatomy Posterior femur above lateral condyle Calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy or calcaneus Calcaneus The largest of the tarsal bones which is situated at the lower and back part of the foot, forming the heel. Foot: Anatomy tendon Plantar flexion Flexion Examination of the Upper Limbs Tibial from anterior rami S1 S1 Heart Sounds S2 S2 Heart Sounds
Tibialis posterior Tibialis posterior Leg: Anatomy Superior tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy and fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy, interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy Several tarsals and metatarsals 2–4 Inversion and plantar flexion Flexion Examination of the Upper Limbs Tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy
Posterior compartment: Deep muscles
Muscle Origin Insertion Action Innervation
Flexor digitorum longus Flexor digitorum longus Leg: Anatomy Posterior tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy Distal phalanges Phalanges Bones that make up the skeleton of the fingers, consisting of two for the thumb, and three for each of the other fingers. Hand: Anatomy 2-5 Plantar flexion Flexion Examination of the Upper Limbs, inversion Tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy
Flexor hallucis longus Flexor hallucis longus Leg: Anatomy Midshaft of fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy, interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy Distal phalanx of big toe Plantar flexion Flexion Examination of the Upper Limbs, inversion Tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy

Neurovasculature

Blood supply

  • Fibular or peroneal artery
    • A branch of the posterior tibial artery
    • Supplies the posterior and lateral components of the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy and ankle joints
    • Surrounds the lateral malleolus of the fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy as the posterior lateral malleolar branch
    • Provides peroneal branches at the ankle
  • Posterior tibial artery
    • A branch of the popliteal artery Popliteal Artery The continuation of the femoral artery coursing through the popliteal fossa; it divides into the anterior and posterior tibial arteries. Popliteal Fossa: Anatomy 
    • Supplies the posterior compartment of the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy, ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot. , and sole of the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy
    • Enters the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy by passing behind the medial malleolus of the tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy, where it provides branches to the ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot.
    • Its terminal branches are the lateral and medial plantar arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology
  • Anterior tibial artery 
    • The terminal branch of the popliteal artery Popliteal Artery The continuation of the femoral artery coursing through the popliteal fossa; it divides into the anterior and posterior tibial arteries. Popliteal Fossa: Anatomy
    • Courses through the anterior (extensor) compartment of the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy
    • Gives off malleolar arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology that anastomose around the ankle:
      • The anterior medial malleolar artery connects with the posterior tibial and medial plantar arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology.
      • The anterior lateral malleolar artery connects with the perforating branch of the fibular artery and the branches of the lateral tarsal artery.
Arterial supply of the ankle

The arterial supply to the ankle: Note that the anterior tibial artery is shown as its continuation, the dorsalis pedis artery Dorsalis pedis artery Foot: Anatomy.

Image by Lecturio.

Nerve supply

The nerve supply of the ankle is provided by the roots from spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord: Anatomy level L4 to S2 S2 Heart Sounds. The following nerves also supply branches to the ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot. :

  • Deep fibular or peroneal nerve Peroneal nerve The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot. Popliteal Fossa: Anatomy
    • 1 of the terminal branches of the common fibular or peroneal nerve Peroneal nerve The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot. Popliteal Fossa: Anatomy
    • Enters the dorsum of the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy under the extensor retinaculum
    • Gives off articular branches to the ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot.
    • An injury would result in weakness of ankle dorsiflexion and extension Extension Examination of the Upper Limbs of all toes.
  • Tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy
    • 1 of the terminal branches of the sciatic nerve Sciatic Nerve A nerve which originates in the lumbar and sacral spinal cord (l4 to s3) and supplies motor and sensory innervation to the lower extremity. The sciatic nerve, which is the main continuation of the sacral plexus, is the largest nerve in the body. It has two major branches, the tibial nerve and the peroneal nerve. Gluteal Region: Anatomy
    • Enters the sole of the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy by passing behind the medial malleolus through the tarsal tunnel 
    • Provides articular branches to the inferior tibiofibular joint and true ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot.  
  • Sural nerve
    • Formed by the merge of the medial sural cutaneous nerve (from the tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy) and the lateral sural cutaneous nerve (from the common fibular or peroneal nerve Peroneal nerve The lateral of the two terminal branches of the sciatic nerve. The peroneal (or fibular) nerve provides motor and sensory innervation to parts of the leg and foot. Popliteal Fossa: Anatomy)
    • Sensation to the posterolateral aspect of the distal ⅓ of the leg Leg The lower leg, or just “leg” in anatomical terms, is the part of the lower limb between the knee and the ankle joint. The bony structure is composed of the tibia and fibula bones, and the muscles of the leg are grouped into the anterior, lateral, and posterior compartments by extensions of fascia. Leg: Anatomy, ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot. , foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy, and heel

Clinical Relevance

  • Ankle sprain: a partial or complete tear in the ligaments of the ankle joint Ankle joint The ankle is a hinged synovial joint formed between the articular surfaces of the distal tibia, distal fibula, and talus. The ankle primarily allows plantar flexion and dorsiflexion of the foot. . An ankle sprain usually occurs via an inversion-type injury to a plantar-flexed and weight-bearing foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy. The lateral ligaments are more likely to be damaged because of their structure and biomechanics of the ankle. The ATFL is the component of the lateral ligament complex that is most commonly injured. An ankle sprain presents with pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, swelling Swelling Inflammation, and a limited ROM after physical trauma, and it is usually related to a fall or a sports-related injury.
  • High ankle sprain: occurs when there is injury to the syndesmosis between the tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy and fibula Fibula The bone of the lower leg lateral to and smaller than the tibia. In proportion to its length, it is the most slender of the long bones. Leg: Anatomy because of an injury of the ankle joints or the interosseous membrane Interosseous Membrane A sheet of fibrous connective tissue rich in collagen often linking two parallel bony structures forming a syndesmosis type joint. It provides longitudinal stability, tensile strength, and weight distribution/transfer and may allow limited movement in syndesmoses. Forearm: Anatomy. The most common mechanism of injury is extreme external rotation Rotation Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. X-rays and dorsiflexion of the ankle.
  • Ankle fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures: the most common fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures of the lower extremity. An ankle fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures is generally caused by twisting the ankle with excessive inversion stress, a mechanism that is most common because the medial malleolus is shorter than the lateral malleolus and the medial deltoid ligaments are stronger than the lateral. An ankle fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures presents as pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways in the affected area, difficulty with weight-bearing, and limited ROM. The diagnosis is confirmed via X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests
  • Tarsal tunnel syndrome Tarsal tunnel syndrome Entrapment of the distal branches of the posterior tibial nerve (which divides into the medial plantar, lateral plantar, and calcaneal nerves) in the tarsal tunnel, which lies posterior to the internal malleolus and beneath the retinaculum of the flexor muscles of the foot. Symptoms include ankle pain radiating into the foot which tends to be aggravated by walking. Examination may reveal tinel’s sign (radiating pain following nerve percussion) over the tibial nerve at the ankle, weakness and atrophy of the small foot muscles, or loss of sensation in the foot. Ankle and Foot Pain: a compressive neuropathy Neuropathy Leprosy caused by compression Compression Blunt Chest Trauma of the tibial nerve Tibial Nerve The medial terminal branch of the sciatic nerve. The tibial nerve fibers originate in lumbar and sacral spinal segments (L4 to S2). They supply motor and sensory innervation to parts of the calf and foot. Popliteal Fossa: Anatomy, which is located under the flexor retinaculum at the posterior–medial aspect of the ankle. The syndrome can be secondary to trauma, rheumatoid arthritis Arthritis Acute or chronic inflammation of joints. Osteoarthritis (RA), postsurgical changes, ganglion cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change, or shoe trauma and generally presents as pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and paresthesia in the medial–plantar surface of the foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy, particularly while walking and standing.
  • Achilles (calcaneal) tendon rupture: a complete or partial tear of the mid-portion of the Achilles tendon when the tendon is stretched beyond capacity. Sudden or unexpected dorsiflexion, pushing off a weight-bearing foot Foot The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons. Foot: Anatomy, or extreme dorsiflexion during a fall from a height may result in an Achilles tendon rupture. The injury presents as sharp pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, a loud “pop” or similar sound, and swelling Swelling Inflammation at the back of the heel. The Achilles tendon is the most commonly ruptured tendon in the body. Partial ruptures may be treated conservatively, while complete ruptures require surgical repair.

References

  1. Drake, RL, Vogl, AW, & Mitchell, AWM. (2014). Gray’s Anatomy for Students (3rd ed.). Philadelphia, PA: Churchill Livingstone.
  2. Netter, FH. (2006). Atlas of Human Anatomy. Philadelphia, PA: Saunders/Elsevier.
  3. Standring, S, & Gray, H. (2016). Gray’s Anatomy: The Anatomical Basis of Clinical Practice.
  4. Biga, L, Dawson, S, Harwell, A, Hopkins, R, Kaufmann, J, LeMaster, M, Matern, P, Morrison-Graham, K, Quick, D, & Runyeon, J. (n.d.). Anatomy and Physiology: Chapter 11. Oregon State University.

USMLE™ is a joint program of the Federation of State Medical Boards (FSMB®) and National Board of Medical Examiners (NBME®). MCAT is a registered trademark of the Association of American Medical Colleges (AAMC). NCLEX®, NCLEX-RN®, and NCLEX-PN® are registered trademarks of the National Council of State Boards of Nursing, Inc (NCSBN®). None of the trademark holders are endorsed by nor affiliated with Lecturio.

Study on the Go

Lecturio Medical complements your studies with evidence-based learning strategies, video lectures, quiz questions, and more – all combined in one easy-to-use resource.

Learn even more with Lecturio:

Complement your med school studies with Lecturio’s all-in-one study companion, delivered with evidence-based learning strategies.

Details