Questions and Answers
Which muscle group in the posterior compartment is responsible for plantar flexion at the ankle joint?
What is the primary action of the Flexor Hallucis Longus?
Which of the following muscles is located most medially in the deep posterior group?
What is the main function of the Tibialis Anterior muscle?
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Where does the Plantaris muscle insert?
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Which muscle is primarily responsible for unlocking the locked knee joint?
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What nerve supplies all the muscles in the posterior compartment of the leg?
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What is the action of the extensor hallucis longus muscle?
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Which nerve supplies the fibularis longus muscle?
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What is the insertion point of the fibularis brevis muscle?
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What is the origin of the extensor digitorum longus?
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Which muscle is primarily responsible for the eversion of the foot at subtalar and transverse tarsal joints?
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What anatomical feature does the tendon of the fibularis longus pass under?
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Which of the following muscles is a deep muscle of the lateral compartment of the leg?
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What is the primary action of the fibularis tertius muscle?
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What action does the popliteus muscle primarily perform?
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Which statement correctly describes the flexor digitorum longus?
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Which of the following muscles contributes to the triceps surae group?
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Where does the tibialis posterior muscle primarily originate?
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What is the insertion point of the gastrocnemius muscle?
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What is the main action of the fibularis longus muscle?
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Which muscle has a superficial location in the lateral compartment of the leg?
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What is the insertion point of the extensor hallucis longus?
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Which statement about fibularis tertius is true?
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Which nerve is responsible for the innervation of the muscles in the lateral compartment of the leg?
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The fibularis longus muscle acts primarily in plantar flexion of the foot at the ankle joint.
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The extensor hallucis longus muscle is located superficially in the leg.
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The fibularis tertius is completely separated from the extensor digitorum longus muscle.
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The deep fibular nerve supplies the fibularis brevis muscle.
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The central slip of each tendon in the foot inserts into the distal phalanx.
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The gastrocnemius muscle aids in the dorsiflexion of the foot at the ankle joint.
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The flexor hallucis longus muscle is located most laterally among the deep posterior muscles.
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The tibialis anterior muscle is primarily responsible for the plantar flexion of the foot.
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The plantaris muscle has a long tendon but a large muscle belly.
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Match the following muscles with their primary actions:
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Match the following muscles with their nerve supply:
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Match the following muscles with their insertion points:
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Match the following muscles with their origins:
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Match the following muscle actions with their corresponding features:
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Which structure passes deep through the inferior extensor retinaculum?
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What branching structure supplies the skin of the inferolateral part of the anterior leg?
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Which of the following structures is located superficial to the inferior extensor retinaculum?
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Which of the following is the correct order of structures passing through the tarsal tunnel from anteromedial to posterolateral?
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The medial and intermediate dorsal cutaneous nerves supply which area?
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Which of the following structures is found posterior to the lateral malleolus, passing superficial to the superior fibular retinaculum?
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Which nerve is responsible for the feeling of sensation in the lateral part of the foot?
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What is the role of the medial and intermediate dorsal cutaneous nerves?
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Which structure is located superficial to the inferior extensor retinaculum?
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Which of the following structures passes through the tarsal tunnel?
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Which of the following statements accurately describes the structures passing anterior to the ankle?
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What is the correct sequence of structures passing through the tarsal tunnel from anteromedial to posterolateral?
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Which nerve supplies the skin on the dorsal surfaces of the toes, excluding the great toe?
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Which structure is supplied by muscular branches of the superficial fibular nerve?
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Which nerve is responsible for providing sensation to the lateral side of the little toe?
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What is the anatomical relationship of the fibers of the superficial fibular nerve in the lower leg?
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Which of the following structures is located deep to the superior fibular retinaculum?
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The median and intermediate dorsal cutaneous nerves supply the skin of the inferolateral part of the anterior leg.
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The tendon of fibularis tertius passes through the tarsal tunnel.
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The great saphenous vein passes deep to the inferior extensor retinaculum.
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The tibial nerve is one of the structures that pass through the tarsal tunnel.
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A notable structure that passes anterior to the ankle is the sural nerve.
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The anterior tibial artery and veins are located superficial to the inferior extensor retinaculum.
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The tendon of flexor hallucis longus is situated anteromedially in the tarsal tunnel.
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The small saphenous vein runs superficial to the superior fibular retinaculum.
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The deep fibular nerve supplies the medial aspect of the foot and the adjacent sides of the great and second toes.
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Match the following structures that pass anterior to the ankle:
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Match the following structures that pass through the tarsal tunnel:
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Match the following branches of the superficial fibular nerve:
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Match the following structures that pass posterior to the lateral malleolus:
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Match the following structures that pass through the inferior extensor retinaculum:
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Which nerve is responsible for the sensory supply to the inferolateral part of the anterior leg?
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What structures pass through the tarsal tunnel in the correct order from anteromedial to posterolateral?
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Which structure is found anterior to the ankle and superficial to the inferior extensor retinaculum?
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Which of the following statements correctly describes the fibularis brevis and fibularis longus muscles?
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Which nerve supplies the skin on the dorsal surfaces of the toes, excluding the adjacent sides of the great and second toes?
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What structure is innervated by branches of the superficial fibular nerve?
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Which structure does NOT pass through the tarsal tunnel?
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Which of the following supplies blood to the anterior leg and is located deep to the inferior extensor retinaculum?
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Which structures pass posterior to the lateral malleolus, superficial to the superior fibular retinaculum?
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Which nerve is responsible for sensory innervation of the lateral side of the little toe?
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Study Notes
Muscles of the Posterior Compartment
- Superficial group includes gastrocnemius, soleus, and plantaris; deep group consists of flexor digitorum longus, flexor hallucis longus, tibialis posterior, and popliteus.
- Muscles separated by transverse intermuscular septum.
- All muscles supplied by the tibial nerve.
Gastrocnemius
- Originates from the distal femur: medial head from the popliteal surface and lateral head from the lateral condyle.
- Joins soleus in a common tendon to form the calcaneal (Achilles) tendon, inserting into the calcaneus.
- Functions in plantar flexion of the foot and assists in leg flexion at the knee.
Soleus
- Located deep to the gastrocnemius.
- Originates from the soleal line and medial border of the tibia, as well as the fibula.
- Inserts into the calcaneus via the calcaneal tendon; works with gastrocnemius as the triceps surae.
- Responsible for plantar flexion of the foot.
Plantaris
- Characterized by a small muscle belly and a long tendon.
- Originates from the lateral supracondylar line of the femur.
- Inserts into the calcaneus, possibly fusing with the calcaneal tendon.
- Assists in plantar flexion of the foot and leg flexion at the knee.
Flexor Digitorum Longus
- Medially located within the deep posterior muscles.
- Originates from the posterior surface of the tibia.
- Inserts into the bases of the distal phalanges of the lateral four toes through tendons that pass under the flexor retinaculum.
- Functions in flexion of the lateral four toes and plantar flexion of the foot.
Flexor Hallucis Longus
- Laterally located deep posterior muscle.
- Originates from the posterior surface of the fibula.
- Inserts into the base of the distal phalanx of the great toe.
- Responsible for flexion of the big toe and plantar flexion of the foot.
Tibialis Posterior
- Deepest muscle in the deep posterior group.
- Originates from the tibia, fibula, and interosseous membrane.
- Inserts into the navicular and other foot bones, aiding in foot inversion and plantar flexion.
Popliteus
- Originates from the lateral condyle of the femur within the knee joint.
- Inserts into the posterior surface of the tibia above the soleal line.
- Functions in medial rotation of the tibia or lateral rotation of the femur, facilitating the 'unlocking' of the knee joint.
Muscles of the Anterior Compartment
- Comprises tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius.
- All muscles innervated by the deep fibular nerve.
Tibialis Anterior
- Located superficially and medially in the anterior compartment.
- Originates from the lateral condyle of the tibia and interosseous membrane.
- Inserts into the medial cuneiform and 1st metatarsal.
- Responsible for dorsiflexion and inversion of the foot.
Extensor Digitorum Longus
- Superficial and laterally located muscle.
- Originates from the lateral condyle of the tibia and medial surface of the fibula.
- Divides into tendons for the lateral four toes, forming extensor expansions.
- Functions in extension of the lateral four toes and dorsiflexion of the foot.
Extensor Hallucis Longus
- Upper part is deep and covered by other muscles but becomes superficial in the lower leg.
- Originates from the fibula and interosseous membrane.
- Inserts into the base of the distal phalanx of the great toe.
- Functions in extension of the great toe and dorsiflexion of the foot.
Fibularis Tertius
- Acts as a lateral slip of the extensor digitorum longus.
- Originates from the fibula and interosseous membrane.
- Inserts into the dorsal aspect of the 5th metatarsal.
- Functions in dorsiflexion and eversion of the foot.
Muscles of the Lateral Compartment
- Includes fibularis longus and fibularis brevis.
- Innervated by the superficial fibular nerve.
Fibularis Longus
- Superficial muscle originating from the fibula.
- Inserts into medial cuneiform and 1st metatarsal after passing behind the lateral malleolus.
- Functions in plantar flexion and eversion of the foot.
Fibularis Brevis
- Lies deep to the fibularis longus.
- Originates from the fibula and inserts into the base of the 5th metatarsal.
- Also responsible for plantar flexion and eversion of the foot.
Muscles of the Posterior Compartment
- Superficial group includes gastrocnemius, soleus, and plantaris; deep group consists of flexor digitorum longus, flexor hallucis longus, tibialis posterior, and popliteus.
- Muscles separated by transverse intermuscular septum.
- All muscles supplied by the tibial nerve.
Gastrocnemius
- Originates from the distal femur: medial head from the popliteal surface and lateral head from the lateral condyle.
- Joins soleus in a common tendon to form the calcaneal (Achilles) tendon, inserting into the calcaneus.
- Functions in plantar flexion of the foot and assists in leg flexion at the knee.
Soleus
- Located deep to the gastrocnemius.
- Originates from the soleal line and medial border of the tibia, as well as the fibula.
- Inserts into the calcaneus via the calcaneal tendon; works with gastrocnemius as the triceps surae.
- Responsible for plantar flexion of the foot.
Plantaris
- Characterized by a small muscle belly and a long tendon.
- Originates from the lateral supracondylar line of the femur.
- Inserts into the calcaneus, possibly fusing with the calcaneal tendon.
- Assists in plantar flexion of the foot and leg flexion at the knee.
Flexor Digitorum Longus
- Medially located within the deep posterior muscles.
- Originates from the posterior surface of the tibia.
- Inserts into the bases of the distal phalanges of the lateral four toes through tendons that pass under the flexor retinaculum.
- Functions in flexion of the lateral four toes and plantar flexion of the foot.
Flexor Hallucis Longus
- Laterally located deep posterior muscle.
- Originates from the posterior surface of the fibula.
- Inserts into the base of the distal phalanx of the great toe.
- Responsible for flexion of the big toe and plantar flexion of the foot.
Tibialis Posterior
- Deepest muscle in the deep posterior group.
- Originates from the tibia, fibula, and interosseous membrane.
- Inserts into the navicular and other foot bones, aiding in foot inversion and plantar flexion.
Popliteus
- Originates from the lateral condyle of the femur within the knee joint.
- Inserts into the posterior surface of the tibia above the soleal line.
- Functions in medial rotation of the tibia or lateral rotation of the femur, facilitating the 'unlocking' of the knee joint.
Muscles of the Anterior Compartment
- Comprises tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius.
- All muscles innervated by the deep fibular nerve.
Tibialis Anterior
- Located superficially and medially in the anterior compartment.
- Originates from the lateral condyle of the tibia and interosseous membrane.
- Inserts into the medial cuneiform and 1st metatarsal.
- Responsible for dorsiflexion and inversion of the foot.
Extensor Digitorum Longus
- Superficial and laterally located muscle.
- Originates from the lateral condyle of the tibia and medial surface of the fibula.
- Divides into tendons for the lateral four toes, forming extensor expansions.
- Functions in extension of the lateral four toes and dorsiflexion of the foot.
Extensor Hallucis Longus
- Upper part is deep and covered by other muscles but becomes superficial in the lower leg.
- Originates from the fibula and interosseous membrane.
- Inserts into the base of the distal phalanx of the great toe.
- Functions in extension of the great toe and dorsiflexion of the foot.
Fibularis Tertius
- Acts as a lateral slip of the extensor digitorum longus.
- Originates from the fibula and interosseous membrane.
- Inserts into the dorsal aspect of the 5th metatarsal.
- Functions in dorsiflexion and eversion of the foot.
Muscles of the Lateral Compartment
- Includes fibularis longus and fibularis brevis.
- Innervated by the superficial fibular nerve.
Fibularis Longus
- Superficial muscle originating from the fibula.
- Inserts into medial cuneiform and 1st metatarsal after passing behind the lateral malleolus.
- Functions in plantar flexion and eversion of the foot.
Fibularis Brevis
- Lies deep to the fibularis longus.
- Originates from the fibula and inserts into the base of the 5th metatarsal.
- Also responsible for plantar flexion and eversion of the foot.
Tendons and Extensors of the Toes
- Each tendon of the toes divides into three slips: a central slip and two lateral slips.
- The central slip inserts into the base of the middle phalanx.
- Lateral slips unite and insert into the base of the distal phalanx, similar to the hand's extensor digitorum.
- Extensor expansions derived from tendons of extensor digitorum longus are located on the dorsal aspects of the proximal phalanges.
- Nerve supply for toe extensors is provided by the deep fibular nerve.
- Actions include extension of the lateral four toes and dorsiflexion of the foot at the ankle joint.
Extensor Hallucis Longus
- Situated deeply in the upper part, it is covered by tibialis anterior and extensor digitorum longus.
- Originates from the medial surface of the fibula and interosseous membrane.
- Inserts into the base of the distal phalanx of the great toe after passing under the extensor retinacula.
- Also supplied by the deep fibular nerve.
- Functions to extend the great toe and dorsiflex the foot.
Fibularis Tertius
- Considered a lateral slip of extensor digitorum longus, rarely entirely detached.
- Originates from the medial surface of the fibula and interosseous membrane.
- Inserts into the dorsal aspects of the 5th metatarsal.
- Innervated by the deep fibular nerve.
- Contributes to dorsiflexion and eversion of the foot.
Muscles of the Lateral Compartment
- Comprised of fibularis longus and fibularis brevis, both supplied by the superficial fibular nerve.
Fibularis Longus
- Superficial muscle located in the lateral compartment.
- Originates on the lateral surfaces of the fibula.
- Its tendon passes behind the lateral malleolus, curves around the cuboid, and inserts into the medial cuneiform and 1st metatarsal.
- Innervation is by the superficial fibular nerve.
- Actions include plantarflexion and eversion of the foot.
Fibularis Brevis
- Lies deeper than fibularis longus.
- Originates from the lateral surface of the fibula.
- Inserts into the tuberosity of the base of the 5th metatarsal.
- Supplied by the superficial fibular nerve.
- Functions similarly to fibularis longus in plantarflexion and eversion.
Muscles of the Posterior Compartment
- Two groups: superficial (gastrocnemius, soleus, plantaris) and deep (flexor digitorum longus, flexor hallucis longus, tibialis posterior, popliteus).
- All are innervated by the tibial nerve.
Gastrocnemius
- Formed by two heads from the distal femur: medial head from the popliteal surface, lateral head from the lateral condyle.
- Joins with soleus to form the calcaneal (Achilles) tendon, inserting into the calcaneus.
- Functions in plantarflexion of the foot and assists with knee flexion.
Soleus
- Deep to gastrocnemius and originates from the soleal line of tibia and posterior fibula.
- Also inserts into the calcaneus via the calcaneal tendon.
- Works alongside gastrocnemius for plantarflexion at the ankle joint.
Plantaris
- Characterized by a small muscle belly and a long tendon.
- Originates from the lateral supracondylar line of the femur.
- Assists in plantarflexion of the foot and flexion of the leg at the knee joint.
Flexor Digitorum Longus
- Most medially located among deep posterior muscles.
- Originates from the posterior surface of the tibia and inserts via four tendons to the distal phalanges of the lateral four toes.
- Functions include flexion of the lateral four toes and plantarflexion of the foot.
Flexor Hallucis Longus
- Located laterally among deep posterior muscles.
- Originates from the fibula and runs under the flexor retinaculum to insert into the distal phalanx of the great toe.
- Actions include flexion of the big toe and plantarflexion of the foot.
Tibialis Posterior
- Deeply placed muscle originating from the tibia and fibula.
- Tendon passes around the medial malleolus and inserts into the navicular with extensions to cuneiforms and metatarsals.
- Functions in plantarflexion and inversion of the foot.
Popliteus
- Positioned within the knee capsule and originates from the lateral condyle of the femur.
- Inserts on the posterior surface of the tibia above the soleal line.
- Functions to rotate the tibia or femur to "unlock" the knee joint when flexion begins.
Muscles of the Anterior Compartment
- Includes tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius.
- All are innervated by the deep fibular nerve.
Tibialis Anterior
- Superficial and medial in the compartment.
- Originates from the tibia and inserts into the medial cuneiform and base of the 1st metatarsal.
- Functions to dorsiflex and invert the foot.
Extensor Digitorum Longus
- Superficial and lateral located in the anterior compartment.
- Originates from the tibia and fibula and divides into four tendons for the lateral four toes.
- Functions in extending the lateral four toes and assisting in dorsiflexion of the foot.
Muscles of the Posterior Compartment
- Superficial group includes gastrocnemius, soleus, and plantaris; deep group consists of flexor digitorum longus, flexor hallucis longus, tibialis posterior, and popliteus.
- Muscles separated by transverse intermuscular septum.
- All muscles supplied by the tibial nerve.
Gastrocnemius
- Originates from the distal femur: medial head from the popliteal surface and lateral head from the lateral condyle.
- Joins soleus in a common tendon to form the calcaneal (Achilles) tendon, inserting into the calcaneus.
- Functions in plantar flexion of the foot and assists in leg flexion at the knee.
Soleus
- Located deep to the gastrocnemius.
- Originates from the soleal line and medial border of the tibia, as well as the fibula.
- Inserts into the calcaneus via the calcaneal tendon; works with gastrocnemius as the triceps surae.
- Responsible for plantar flexion of the foot.
Plantaris
- Characterized by a small muscle belly and a long tendon.
- Originates from the lateral supracondylar line of the femur.
- Inserts into the calcaneus, possibly fusing with the calcaneal tendon.
- Assists in plantar flexion of the foot and leg flexion at the knee.
Flexor Digitorum Longus
- Medially located within the deep posterior muscles.
- Originates from the posterior surface of the tibia.
- Inserts into the bases of the distal phalanges of the lateral four toes through tendons that pass under the flexor retinaculum.
- Functions in flexion of the lateral four toes and plantar flexion of the foot.
Flexor Hallucis Longus
- Laterally located deep posterior muscle.
- Originates from the posterior surface of the fibula.
- Inserts into the base of the distal phalanx of the great toe.
- Responsible for flexion of the big toe and plantar flexion of the foot.
Tibialis Posterior
- Deepest muscle in the deep posterior group.
- Originates from the tibia, fibula, and interosseous membrane.
- Inserts into the navicular and other foot bones, aiding in foot inversion and plantar flexion.
Popliteus
- Originates from the lateral condyle of the femur within the knee joint.
- Inserts into the posterior surface of the tibia above the soleal line.
- Functions in medial rotation of the tibia or lateral rotation of the femur, facilitating the 'unlocking' of the knee joint.
Muscles of the Anterior Compartment
- Comprises tibialis anterior, extensor digitorum longus, extensor hallucis longus, and fibularis tertius.
- All muscles innervated by the deep fibular nerve.
Tibialis Anterior
- Located superficially and medially in the anterior compartment.
- Originates from the lateral condyle of the tibia and interosseous membrane.
- Inserts into the medial cuneiform and 1st metatarsal.
- Responsible for dorsiflexion and inversion of the foot.
Extensor Digitorum Longus
- Superficial and laterally located muscle.
- Originates from the lateral condyle of the tibia and medial surface of the fibula.
- Divides into tendons for the lateral four toes, forming extensor expansions.
- Functions in extension of the lateral four toes and dorsiflexion of the foot.
Extensor Hallucis Longus
- Upper part is deep and covered by other muscles but becomes superficial in the lower leg.
- Originates from the fibula and interosseous membrane.
- Inserts into the base of the distal phalanx of the great toe.
- Functions in extension of the great toe and dorsiflexion of the foot.
Fibularis Tertius
- Acts as a lateral slip of the extensor digitorum longus.
- Originates from the fibula and interosseous membrane.
- Inserts into the dorsal aspect of the 5th metatarsal.
- Functions in dorsiflexion and eversion of the foot.
Muscles of the Lateral Compartment
- Includes fibularis longus and fibularis brevis.
- Innervated by the superficial fibular nerve.
Fibularis Longus
- Superficial muscle originating from the fibula.
- Inserts into medial cuneiform and 1st metatarsal after passing behind the lateral malleolus.
- Functions in plantar flexion and eversion of the foot.
Fibularis Brevis
- Lies deep to the fibularis longus.
- Originates from the fibula and inserts into the base of the 5th metatarsal.
- Also responsible for plantar flexion and eversion of the foot.
Cutaneous Innervation of the Leg
- Anterior surface of the leg is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: superficial fibular (peroneal) nerve
- Medial aspect: saphenous nerve
- Posterior surface is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: sural nerve
- Medial aspect: saphenous nerve
Compartments of the Leg
- Crural fascia envelops the leg like a stocking and merges with fascia lata above.
- Anterior and posterior intermuscular septa originate from crural fascia to fibula.
- Interosseous membrane connects the borders of tibia and fibula, facilitating muscle attachment and providing stability.
- Three compartments of the leg include anterior, lateral, and posterior, each containing distinct muscles, vessels, and nerves.
- The posterior compartment features superficial and deep sections, separated by the transverse intermuscular septum.
Retinacula of the Ankle
- Retinacula keep tendons close to bones, preventing bowstringing.
- Two types of extensor retinacula are present:
- Superior extensor retinaculum: attaches to the distal ends of the anterior borders of the tibia and fibula.
- Inferior extensor retinaculum: Y-shaped structure anchored to the calcaneus, medial malleolus, and continuous with the deep fascia of the foot.
Flexor Retinaculum
- Located on the medial side of the ankle, extending from medial malleolus to calcaneus.
- Forms the tarsal tunnel, allowing passage of tendons, vessels, and nerves from the posterior leg compartment to the foot.
Fibular (Peroneal) Retinacula
- Superior fibular retinaculum: spans from lateral malleolus to the calcaneus.
- Inferior fibular retinaculum: attaches at both ends to the lateral surface of the calcaneus.
Posterior Tibial Artery
- Terminal branch of the popliteal artery, beginning at the popliteus muscle's lower border.
- Runs inferiorly in the deep posterior compartment, tracking with posterior tibial veins and tibial nerve.
- Pulse can be palpated behind the medial malleolus.
- Divides into medial and lateral plantar arteries under the flexor retinaculum.
- Major branches include the fibular artery and circumflex fibular artery, providing blood supply to muscles, anastomoses around the knee, and heel.
Tibial Nerve
- Terminal branch of the sciatic nerve found in the lower third of the posterior thigh.
- Accompanies the posterior tibial artery and veins through the posterior compartment.
- Divides into medial and lateral plantar nerves beneath the flexor retinaculum.
- Supplies muscles in the posterior compartment and the skin of the medial heel.
Anterior Tibial Artery
- Terminal branch of the popliteal artery, entering the anterior compartment of the leg via the interosseous membrane.
- In the upper two-thirds, located deep; in the lower third, superficial in front of the distal tibia.
- Continues as dorsalis pedis artery at the ankle.
- Accompanies anterior tibial veins and deep fibular nerve.
Deep Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, originating beneath the fibularis longus muscle.
- Pierces the anterior intermuscular septum to enter the anterior compartment alongside the anterior tibial artery.
- Supplies muscles of the anterior compartment and the ankle joint.
Avulsion Fracture of the Tuberosity of the 5th Metatarsal
- Occurs when the foot is forcibly inverted, pulling away the tuberosity by the fibularis brevis tendon.
- Common in athletes, particularly basketball and tennis players, associated with severe ankle sprains.
- Symptoms include pain, swelling, and bruising at the fifth metatarsal base.
Blood Supply of the Lateral Compartment
- Lacks a vertical main artery; relies on anterior tibial and fibular arteries.
- Branches from the anterior tibial artery and fibular artery perforate the intermuscular septa to supply the lateral compartment.
Superficial Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, initially deep to fibularis longus.
- Descends between fibularis longus/brevis and extensor digitorum longus, becoming superficial in the lower leg.
- Provides muscular branches to fibularis longus and brevis, and cutaneous branches for the skin of the anterior leg and dorsum of the foot.
Structures Passing at the Ankle
- Anterior to the ankle, superficial to the inferior extensor retinaculum:
- Saphenous nerve, great saphenous vein, and branches of the superficial fibular nerve.
- Anterior to the ankle, deep to the inferior extensor retinaculum:
- Tendons of tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius, along with anterior tibial artery and deep fibular nerve.
Structures in the Tarsal Tunnel
- Pass under the flexor retinaculum from anteromedial to posterolateral:
- Tibialis posterior tendon, flexor digitorum longus tendon, posterior tibial artery and veins, tibial nerve, flexor hallucis longus tendon.
Structures Behind the Lateral Malleolus
- Superficial to the superior fibular retinaculum:
- Sural nerve and small saphenous vein.
- Deep to the superior fibular retinaculum:
- Tendons of fibularis brevis and longus.
Cutaneous Innervation of the Leg
- Anterior surface of the leg is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: superficial fibular (peroneal) nerve
- Medial aspect: saphenous nerve
- Posterior surface is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: sural nerve
- Medial aspect: saphenous nerve
Compartments of the Leg
- Crural fascia envelops the leg like a stocking and merges with fascia lata above.
- Anterior and posterior intermuscular septa originate from crural fascia to fibula.
- Interosseous membrane connects the borders of tibia and fibula, facilitating muscle attachment and providing stability.
- Three compartments of the leg include anterior, lateral, and posterior, each containing distinct muscles, vessels, and nerves.
- The posterior compartment features superficial and deep sections, separated by the transverse intermuscular septum.
Retinacula of the Ankle
- Retinacula keep tendons close to bones, preventing bowstringing.
- Two types of extensor retinacula are present:
- Superior extensor retinaculum: attaches to the distal ends of the anterior borders of the tibia and fibula.
- Inferior extensor retinaculum: Y-shaped structure anchored to the calcaneus, medial malleolus, and continuous with the deep fascia of the foot.
Flexor Retinaculum
- Located on the medial side of the ankle, extending from medial malleolus to calcaneus.
- Forms the tarsal tunnel, allowing passage of tendons, vessels, and nerves from the posterior leg compartment to the foot.
Fibular (Peroneal) Retinacula
- Superior fibular retinaculum: spans from lateral malleolus to the calcaneus.
- Inferior fibular retinaculum: attaches at both ends to the lateral surface of the calcaneus.
Posterior Tibial Artery
- Terminal branch of the popliteal artery, beginning at the popliteus muscle's lower border.
- Runs inferiorly in the deep posterior compartment, tracking with posterior tibial veins and tibial nerve.
- Pulse can be palpated behind the medial malleolus.
- Divides into medial and lateral plantar arteries under the flexor retinaculum.
- Major branches include the fibular artery and circumflex fibular artery, providing blood supply to muscles, anastomoses around the knee, and heel.
Tibial Nerve
- Terminal branch of the sciatic nerve found in the lower third of the posterior thigh.
- Accompanies the posterior tibial artery and veins through the posterior compartment.
- Divides into medial and lateral plantar nerves beneath the flexor retinaculum.
- Supplies muscles in the posterior compartment and the skin of the medial heel.
Anterior Tibial Artery
- Terminal branch of the popliteal artery, entering the anterior compartment of the leg via the interosseous membrane.
- In the upper two-thirds, located deep; in the lower third, superficial in front of the distal tibia.
- Continues as dorsalis pedis artery at the ankle.
- Accompanies anterior tibial veins and deep fibular nerve.
Deep Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, originating beneath the fibularis longus muscle.
- Pierces the anterior intermuscular septum to enter the anterior compartment alongside the anterior tibial artery.
- Supplies muscles of the anterior compartment and the ankle joint.
Avulsion Fracture of the Tuberosity of the 5th Metatarsal
- Occurs when the foot is forcibly inverted, pulling away the tuberosity by the fibularis brevis tendon.
- Common in athletes, particularly basketball and tennis players, associated with severe ankle sprains.
- Symptoms include pain, swelling, and bruising at the fifth metatarsal base.
Blood Supply of the Lateral Compartment
- Lacks a vertical main artery; relies on anterior tibial and fibular arteries.
- Branches from the anterior tibial artery and fibular artery perforate the intermuscular septa to supply the lateral compartment.
Superficial Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, initially deep to fibularis longus.
- Descends between fibularis longus/brevis and extensor digitorum longus, becoming superficial in the lower leg.
- Provides muscular branches to fibularis longus and brevis, and cutaneous branches for the skin of the anterior leg and dorsum of the foot.
Structures Passing at the Ankle
- Anterior to the ankle, superficial to the inferior extensor retinaculum:
- Saphenous nerve, great saphenous vein, and branches of the superficial fibular nerve.
- Anterior to the ankle, deep to the inferior extensor retinaculum:
- Tendons of tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius, along with anterior tibial artery and deep fibular nerve.
Structures in the Tarsal Tunnel
- Pass under the flexor retinaculum from anteromedial to posterolateral:
- Tibialis posterior tendon, flexor digitorum longus tendon, posterior tibial artery and veins, tibial nerve, flexor hallucis longus tendon.
Structures Behind the Lateral Malleolus
- Superficial to the superior fibular retinaculum:
- Sural nerve and small saphenous vein.
- Deep to the superior fibular retinaculum:
- Tendons of fibularis brevis and longus.
Cutaneous Innervation of the Leg
- Anterior surface of the leg is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: superficial fibular (peroneal) nerve
- Medial aspect: saphenous nerve
- Posterior surface is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: sural nerve
- Medial aspect: saphenous nerve
Compartments of the Leg
- Crural fascia envelops the leg like a stocking and merges with fascia lata above.
- Anterior and posterior intermuscular septa originate from crural fascia to fibula.
- Interosseous membrane connects the borders of tibia and fibula, facilitating muscle attachment and providing stability.
- Three compartments of the leg include anterior, lateral, and posterior, each containing distinct muscles, vessels, and nerves.
- The posterior compartment features superficial and deep sections, separated by the transverse intermuscular septum.
Retinacula of the Ankle
- Retinacula keep tendons close to bones, preventing bowstringing.
- Two types of extensor retinacula are present:
- Superior extensor retinaculum: attaches to the distal ends of the anterior borders of the tibia and fibula.
- Inferior extensor retinaculum: Y-shaped structure anchored to the calcaneus, medial malleolus, and continuous with the deep fascia of the foot.
Flexor Retinaculum
- Located on the medial side of the ankle, extending from medial malleolus to calcaneus.
- Forms the tarsal tunnel, allowing passage of tendons, vessels, and nerves from the posterior leg compartment to the foot.
Fibular (Peroneal) Retinacula
- Superior fibular retinaculum: spans from lateral malleolus to the calcaneus.
- Inferior fibular retinaculum: attaches at both ends to the lateral surface of the calcaneus.
Posterior Tibial Artery
- Terminal branch of the popliteal artery, beginning at the popliteus muscle's lower border.
- Runs inferiorly in the deep posterior compartment, tracking with posterior tibial veins and tibial nerve.
- Pulse can be palpated behind the medial malleolus.
- Divides into medial and lateral plantar arteries under the flexor retinaculum.
- Major branches include the fibular artery and circumflex fibular artery, providing blood supply to muscles, anastomoses around the knee, and heel.
Tibial Nerve
- Terminal branch of the sciatic nerve found in the lower third of the posterior thigh.
- Accompanies the posterior tibial artery and veins through the posterior compartment.
- Divides into medial and lateral plantar nerves beneath the flexor retinaculum.
- Supplies muscles in the posterior compartment and the skin of the medial heel.
Anterior Tibial Artery
- Terminal branch of the popliteal artery, entering the anterior compartment of the leg via the interosseous membrane.
- In the upper two-thirds, located deep; in the lower third, superficial in front of the distal tibia.
- Continues as dorsalis pedis artery at the ankle.
- Accompanies anterior tibial veins and deep fibular nerve.
Deep Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, originating beneath the fibularis longus muscle.
- Pierces the anterior intermuscular septum to enter the anterior compartment alongside the anterior tibial artery.
- Supplies muscles of the anterior compartment and the ankle joint.
Avulsion Fracture of the Tuberosity of the 5th Metatarsal
- Occurs when the foot is forcibly inverted, pulling away the tuberosity by the fibularis brevis tendon.
- Common in athletes, particularly basketball and tennis players, associated with severe ankle sprains.
- Symptoms include pain, swelling, and bruising at the fifth metatarsal base.
Blood Supply of the Lateral Compartment
- Lacks a vertical main artery; relies on anterior tibial and fibular arteries.
- Branches from the anterior tibial artery and fibular artery perforate the intermuscular septa to supply the lateral compartment.
Superficial Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, initially deep to fibularis longus.
- Descends between fibularis longus/brevis and extensor digitorum longus, becoming superficial in the lower leg.
- Provides muscular branches to fibularis longus and brevis, and cutaneous branches for the skin of the anterior leg and dorsum of the foot.
Structures Passing at the Ankle
- Anterior to the ankle, superficial to the inferior extensor retinaculum:
- Saphenous nerve, great saphenous vein, and branches of the superficial fibular nerve.
- Anterior to the ankle, deep to the inferior extensor retinaculum:
- Tendons of tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius, along with anterior tibial artery and deep fibular nerve.
Structures in the Tarsal Tunnel
- Pass under the flexor retinaculum from anteromedial to posterolateral:
- Tibialis posterior tendon, flexor digitorum longus tendon, posterior tibial artery and veins, tibial nerve, flexor hallucis longus tendon.
Structures Behind the Lateral Malleolus
- Superficial to the superior fibular retinaculum:
- Sural nerve and small saphenous vein.
- Deep to the superior fibular retinaculum:
- Tendons of fibularis brevis and longus.
Cutaneous Innervation of the Leg
- Anterior surface of the leg is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: superficial fibular (peroneal) nerve
- Medial aspect: saphenous nerve
- Posterior surface is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: sural nerve
- Medial aspect: saphenous nerve
Compartments of the Leg
- Crural fascia envelops the leg like a stocking and merges with fascia lata above.
- Anterior and posterior intermuscular septa originate from crural fascia to fibula.
- Interosseous membrane connects the borders of tibia and fibula, facilitating muscle attachment and providing stability.
- Three compartments of the leg include anterior, lateral, and posterior, each containing distinct muscles, vessels, and nerves.
- The posterior compartment features superficial and deep sections, separated by the transverse intermuscular septum.
Retinacula of the Ankle
- Retinacula keep tendons close to bones, preventing bowstringing.
- Two types of extensor retinacula are present:
- Superior extensor retinaculum: attaches to the distal ends of the anterior borders of the tibia and fibula.
- Inferior extensor retinaculum: Y-shaped structure anchored to the calcaneus, medial malleolus, and continuous with the deep fascia of the foot.
Flexor Retinaculum
- Located on the medial side of the ankle, extending from medial malleolus to calcaneus.
- Forms the tarsal tunnel, allowing passage of tendons, vessels, and nerves from the posterior leg compartment to the foot.
Fibular (Peroneal) Retinacula
- Superior fibular retinaculum: spans from lateral malleolus to the calcaneus.
- Inferior fibular retinaculum: attaches at both ends to the lateral surface of the calcaneus.
Posterior Tibial Artery
- Terminal branch of the popliteal artery, beginning at the popliteus muscle's lower border.
- Runs inferiorly in the deep posterior compartment, tracking with posterior tibial veins and tibial nerve.
- Pulse can be palpated behind the medial malleolus.
- Divides into medial and lateral plantar arteries under the flexor retinaculum.
- Major branches include the fibular artery and circumflex fibular artery, providing blood supply to muscles, anastomoses around the knee, and heel.
Tibial Nerve
- Terminal branch of the sciatic nerve found in the lower third of the posterior thigh.
- Accompanies the posterior tibial artery and veins through the posterior compartment.
- Divides into medial and lateral plantar nerves beneath the flexor retinaculum.
- Supplies muscles in the posterior compartment and the skin of the medial heel.
Anterior Tibial Artery
- Terminal branch of the popliteal artery, entering the anterior compartment of the leg via the interosseous membrane.
- In the upper two-thirds, located deep; in the lower third, superficial in front of the distal tibia.
- Continues as dorsalis pedis artery at the ankle.
- Accompanies anterior tibial veins and deep fibular nerve.
Deep Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, originating beneath the fibularis longus muscle.
- Pierces the anterior intermuscular septum to enter the anterior compartment alongside the anterior tibial artery.
- Supplies muscles of the anterior compartment and the ankle joint.
Avulsion Fracture of the Tuberosity of the 5th Metatarsal
- Occurs when the foot is forcibly inverted, pulling away the tuberosity by the fibularis brevis tendon.
- Common in athletes, particularly basketball and tennis players, associated with severe ankle sprains.
- Symptoms include pain, swelling, and bruising at the fifth metatarsal base.
Blood Supply of the Lateral Compartment
- Lacks a vertical main artery; relies on anterior tibial and fibular arteries.
- Branches from the anterior tibial artery and fibular artery perforate the intermuscular septa to supply the lateral compartment.
Superficial Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, initially deep to fibularis longus.
- Descends between fibularis longus/brevis and extensor digitorum longus, becoming superficial in the lower leg.
- Provides muscular branches to fibularis longus and brevis, and cutaneous branches for the skin of the anterior leg and dorsum of the foot.
Structures Passing at the Ankle
- Anterior to the ankle, superficial to the inferior extensor retinaculum:
- Saphenous nerve, great saphenous vein, and branches of the superficial fibular nerve.
- Anterior to the ankle, deep to the inferior extensor retinaculum:
- Tendons of tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius, along with anterior tibial artery and deep fibular nerve.
Structures in the Tarsal Tunnel
- Pass under the flexor retinaculum from anteromedial to posterolateral:
- Tibialis posterior tendon, flexor digitorum longus tendon, posterior tibial artery and veins, tibial nerve, flexor hallucis longus tendon.
Structures Behind the Lateral Malleolus
- Superficial to the superior fibular retinaculum:
- Sural nerve and small saphenous vein.
- Deep to the superior fibular retinaculum:
- Tendons of fibularis brevis and longus.
Cutaneous Innervation of the Leg
- Anterior surface of the leg is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: superficial fibular (peroneal) nerve
- Medial aspect: saphenous nerve
- Posterior surface is innervated by:
- Superolateral area: lateral sural cutaneous nerve
- Inferolateral area: sural nerve
- Medial aspect: saphenous nerve
Compartments of the Leg
- Crural fascia envelops the leg like a stocking and merges with fascia lata above.
- Anterior and posterior intermuscular septa originate from crural fascia to fibula.
- Interosseous membrane connects the borders of tibia and fibula, facilitating muscle attachment and providing stability.
- Three compartments of the leg include anterior, lateral, and posterior, each containing distinct muscles, vessels, and nerves.
- The posterior compartment features superficial and deep sections, separated by the transverse intermuscular septum.
Retinacula of the Ankle
- Retinacula keep tendons close to bones, preventing bowstringing.
- Two types of extensor retinacula are present:
- Superior extensor retinaculum: attaches to the distal ends of the anterior borders of the tibia and fibula.
- Inferior extensor retinaculum: Y-shaped structure anchored to the calcaneus, medial malleolus, and continuous with the deep fascia of the foot.
Flexor Retinaculum
- Located on the medial side of the ankle, extending from medial malleolus to calcaneus.
- Forms the tarsal tunnel, allowing passage of tendons, vessels, and nerves from the posterior leg compartment to the foot.
Fibular (Peroneal) Retinacula
- Superior fibular retinaculum: spans from lateral malleolus to the calcaneus.
- Inferior fibular retinaculum: attaches at both ends to the lateral surface of the calcaneus.
Posterior Tibial Artery
- Terminal branch of the popliteal artery, beginning at the popliteus muscle's lower border.
- Runs inferiorly in the deep posterior compartment, tracking with posterior tibial veins and tibial nerve.
- Pulse can be palpated behind the medial malleolus.
- Divides into medial and lateral plantar arteries under the flexor retinaculum.
- Major branches include the fibular artery and circumflex fibular artery, providing blood supply to muscles, anastomoses around the knee, and heel.
Tibial Nerve
- Terminal branch of the sciatic nerve found in the lower third of the posterior thigh.
- Accompanies the posterior tibial artery and veins through the posterior compartment.
- Divides into medial and lateral plantar nerves beneath the flexor retinaculum.
- Supplies muscles in the posterior compartment and the skin of the medial heel.
Anterior Tibial Artery
- Terminal branch of the popliteal artery, entering the anterior compartment of the leg via the interosseous membrane.
- In the upper two-thirds, located deep; in the lower third, superficial in front of the distal tibia.
- Continues as dorsalis pedis artery at the ankle.
- Accompanies anterior tibial veins and deep fibular nerve.
Deep Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, originating beneath the fibularis longus muscle.
- Pierces the anterior intermuscular septum to enter the anterior compartment alongside the anterior tibial artery.
- Supplies muscles of the anterior compartment and the ankle joint.
Avulsion Fracture of the Tuberosity of the 5th Metatarsal
- Occurs when the foot is forcibly inverted, pulling away the tuberosity by the fibularis brevis tendon.
- Common in athletes, particularly basketball and tennis players, associated with severe ankle sprains.
- Symptoms include pain, swelling, and bruising at the fifth metatarsal base.
Blood Supply of the Lateral Compartment
- Lacks a vertical main artery; relies on anterior tibial and fibular arteries.
- Branches from the anterior tibial artery and fibular artery perforate the intermuscular septa to supply the lateral compartment.
Superficial Fibular (Peroneal) Nerve
- Terminal branch of the common fibular nerve, initially deep to fibularis longus.
- Descends between fibularis longus/brevis and extensor digitorum longus, becoming superficial in the lower leg.
- Provides muscular branches to fibularis longus and brevis, and cutaneous branches for the skin of the anterior leg and dorsum of the foot.
Structures Passing at the Ankle
- Anterior to the ankle, superficial to the inferior extensor retinaculum:
- Saphenous nerve, great saphenous vein, and branches of the superficial fibular nerve.
- Anterior to the ankle, deep to the inferior extensor retinaculum:
- Tendons of tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius, along with anterior tibial artery and deep fibular nerve.
Structures in the Tarsal Tunnel
- Pass under the flexor retinaculum from anteromedial to posterolateral:
- Tibialis posterior tendon, flexor digitorum longus tendon, posterior tibial artery and veins, tibial nerve, flexor hallucis longus tendon.
Structures Behind the Lateral Malleolus
- Superficial to the superior fibular retinaculum:
- Sural nerve and small saphenous vein.
- Deep to the superior fibular retinaculum:
- Tendons of fibularis brevis and longus.
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Description
This quiz covers the muscles in the posterior compartment of the leg, focusing on both the superficial and deep muscle groups. Key muscles include the gastrocnemius, soleus, and tibialis posterior, among others. Explore the roles of these muscles and their nerve supply.
