Session 5: Functional Anatomy of the Foot and Ankle Flashcards
The bones of the foot can be divided into three gross groups. Which? Say how many of each as well.
- Tarsal bones - 7 bones situated proximally
- Metatarsal bones - in between tarsal and phalanges. 5 in total, one for each toe.
- Phalanges - These are the bones of the toe. Each toe has 3 phalanges except for the big toe which only has 2.
What type of bone are the tarsal bones?
Irregular.
The foot can be divided into three regions. Which?
- Hindfoot
- Midfoot
- Forefoot
Which bones can be found in the hind foot?
The talus and calcaneus bones.
Which bones can be found in the mid foot?
The navicular, the cuboid and the cuneiforms bones.
Which bones can be found in the forefoot?
The metatarsals and the phalanges.
Which is the most superior bone of the foot/tarsal bones?
The talus.
What three articulations does the talus have?
Ankle joint between talus trochlear, tibia and fibula superiorly.
Subtalar join between talus and calcaneus inferiorly.
Talonavicular joint between the talus and navicular anteriorly.
What is the main function of the talus?
To transmit forces from the tibia to the calcaneus.
Mention the muscles that insert and originate from the talus.
No muscles insert or originate in the talus.
Why does the talus heal poorly?
Because of avascular necrosis. The blood supply is retrograde which means that it comes from the distal ends of the foot into the talus. It also lacks muscle attachments.
This makes the talus less effective of healing.
Which is the largest tarsal bone? Where can it be found?
The calcaneus which can be found inferior to the talus. (Heel)
What articulations does the calcaneus have?
Subtalar joint also called talocalcaneal joint between the talus and calcaneus superiorly.
Calcaneocuboid joint between the calcaneus and the cuboid which can be found anteriorly.
There is a protrusion posteriorly on the calcaneus. What is it called and what is its function?
It is called calcaneal tuberosity, here the achilles tendon attaches.
The calcaneus takes the full weight of the body when the heel contacts the ground when walking.
What is the proximal row of the tarsal bones?
The calcaneus and the talus.
What is the intermediate row of the tarsal bones?
It consists of only one bone and that is the navicular.
Location, articulation and insertion/origination of the the navicular bone.
Found medially articulating with the talus posteriorly and with all three cuneiform bones anteriorly and the cuboid bone laterally.
On the plantar surface of the navicular there is a tuberosity for the insertion of part of the tibias posterior tendon.
What is the distal row of the tarsal bones?
Four tarsal bones: cuboid, and the lateral, intermediate and medial cuneiforms bones.
Location, articulation and insertion/origination of the cuboid bone.
Furthest lateral.
Articulates proximally with the calcaneus and distally with the fourth and fifth metatarsals.
Plantar surface of the cuboid has a groove for the insertion of tendon of peroneus (fibularis) longus.
Location, articulation and function of the three cuneiforms.
Medial to the cuboid.
Articulates with the navicular proximally and distally with the first, second and third metatarsals.
Wedge shape of the cuneiform bones helps to form the transverse arch of the foot.
How are the metatarsals numbered?
By Roman numerals. I medially and V laterally.
What are the joints between the metatarsals and the tarsal bones called?
Tarsometatarsal joints.
What are the joints between the metatarsals called?
Intermetatarsal joints.
What are the joints between the metatarsal head and the proximal phalanx called?
Metatarsophalangeal joints.
What does each metatarsal consist of?
A base, a shaft, a neck, and a head.
What does each phalanx consist of?
A base, a shaft and a head.
What is the ankle mortise?
A bracket-shaped socket.
How is the ankle mortise formed?
By the tibia and fibula via tibiofibular ligaments at the distal tibiofibular joint.
What bone, and what part of that bone fits into the ankle mortise?
The trochlea of the talus.
What is dorsiflexion and what part of the trochlea of the talus fits into the ankle mortise at dorsiflexion?
Dorsiflexion is when you flex your foot upwards pointing toes at sky.
The anterior part of the trochlea of the talus is in the mortise at this point.
What is plantarflexion and what part of the trochlea of the talus fits into the ankle mortise at plantarflexion?
Plantarflexion is when you flex your foot downwards pointing toes at ground.
The posterior part of the trochlea of the talus is in the mortise at this point.
What are the movements allowed at the ankle joint?
Only dorsi and plantar flexion.
What type of flexion is most stable at the ankle joint and why?
Dorsiflexion is more stable because the anterior part of the trochlea of the talus is larger and that makes it more stable.
Posterior part of the trochlea of the talus is more narrow.
What muscles are involved in plantarflexion?
Posterior part of the leg: gastrocnemius, soles, planters and tibialis posterior.
What muscles are involved in dorsiflexion?
Anterior part of the leg: tibialis anterior, extensor hallucis longus, extensor digitorum longus and peroneus tertius.
The lateral ligament of the ankle has three parts. Which? Which bones do they connect?
Anterior talofibular ligament between lateral malleolus and the neck of the talus.
Posterior talofibular ligament between the malleolar fossa and the lateral tubercle of the talus.
Calcaneofibular ligament between the tip of the lateral malleolus and the lateral surface of the calcaneus.
What is the main function of the lateral ligaments of the ankle?
To resist inversion of the foot.
What are the medial ligaments of the ankle? Which bones do they connect?
There is only one which arches and is called the medial or deltoid ligament. It is stronger and resists excessive eversion of the foot.
From medial malleolus to attach to the talus, calcaneus and the navicular.
Where does inversion and eversion of the foot occur?
NOT at the ankle joint but at the subtalar, calcaneocuboid and the talocalcaneonavicular joints of the mid foot.
Why is inversion and eversion important?
Because it allows us to walk on uneven surfaces.
What type of joint can be found between the talus and calcaneus and what type of joint is it?
The subtalar joint and it is a plane type of synovial joint.
Why is the subtalar joint important?
Because it is the major joint within the foot at which eversion and inversion take place.
What muscles are involved in eversion?
Lateral compartment of the leg: peroneus longus and peroneus brevis.
Anterior compartment of the leg: peroneus tertius.
What muscles are involved in inversion?
Anterior compartment: Tibialis anterior
Posterior compartment: Tibialis posterior
What are the main weight bearing bones during standing?
The heel and also the heads of the metatarsals.
What are the three arches of the foot?
The medial longitudinal arch
The lateral longitudinal arch
The anterior transverse arch
How are the arches maintained in shape?
By interlocking bones, the ligaments of the foot and the intrinsic muscles of the foot and the pull of the long tendons of extrinsic muscles.
What is the medial longitudinal arch formed by?
The calcaneus, the talus, navicular, the three cuneiforms and the medial three metatarsals.
What other structures are important to maintain the integrity of the medial longitudinal arch?
Plantar aponeurosis Spring ligament Tibialis anterior Peroneus (fibularis) longus Tibialis posterior Flexor hallucis longus
What is the lateral longitudinal arch formed by?
The calcaneus, the cuboid and the lateral two metatarsals.
What other structures are important to maintain the integrity of the lateral longitudinal arch?
Contraction of peroneus brevis muscle can help supporting the integrity of the lateral longitudinal arch.
Which are the four muscles of the anterior compartment of the leg?
Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Peroneus tertius
What movements do they involve?
Dorsiflexion and inversion of the foot at the ankle joint.
What nerves innervate these muscles?
Deep peroneal (fibular) nerve
What artery supply these muscles?
The anterior tibial artery
Origination, insertion, action and innervation of tibialis anterior.
Located medially.
Originates from the lateral surface of the tibia.
Insert onto the medial cuneiform and the base of the first metatarsal.
Dorsiflexion and inversion of the foot.
Innervated by deep fibular nerve.
Origination, insertion, action and innervation of extensor digitorum longus.
Located laterally and deep to tibialis anterior.
Originates from the lateral condyle of the tibia, the medial surface of the fibula and the interosseus membrane.
Inserts into single tendon which then divides into four tendons which insert onto the middle and distal phalanges of the second to fifth toes.
Extension of the lateral four toes and dorsiflexion of the foot.
Innervation by deep fibular nerve.
Origination, insertion, action and innervation of extensor hallucis longus.
Located deep to extensor digitorum longs and tibialis anterior.
Originates from the medial surface of the fibular shaft.
Inserts to the base of the distal phalanx of the great toe.
Extension of great to and dorsiflexion of the foot.
Innervated by deep fibular nerve.
Origination, insertion, action and innervation of peroneus (fibularis) tertius.
Originates from the medial surface of the fibula, inferior to the origin of the extensor digitorum longus.
Inserts onto the base of the fifth metatarsal.
Eversion of the foot and dorsiflexion.
Innervated by deep fibular nerve.
What are the two muscles in the lateral compartment of the leg?
Peroneus fibularis longus and peroneus fibularis brevis.
Origination, insertion, action and innervation of peroneus fibularis longus.
More superficial than brevis.
Originates from the upper lateral surface of the fibula and the lateral tibial condyle.
Goes into a tendon and inserts onto the plantar surface of the medial cuneiform and base of the first metatarsal.
Eversion and plantarflexion of the foot. Also supports the medial and transverse arches of the foot.
Innervated by superficial fibular (peroneal) nerve.
What is the root value of the superficial fibular peroneal nerve?
L4-S1
What is the root value of the deep fibular nerve?
L4-L5
Origination, insertion, action and innervation of peroneus fibularis brevis.
Deeper than longus.
Originates from the inferolateral surface of the fibular shaft. Goes into a tendon.
Inserts onto a tubercle on the base of the fifth metatarsal.
Eversion of the foot.
Innervated by superficial fibular peroneal nerve
The muscles in the posterior compartment of the leg are divided into two smaller compartments. Which? What are they separated by?
Superficial posterior compartment
Deep posterior compartment.
By fascia.
What are the muscles in the posterior compartments innervated by?
The tibial nerve which is a terminal branch of the sciatic nerve.
The muscles of the superficial posterior compartment all insert into the same point. Where?
The calcaneus via the calcaneal (achilles) tendon.
Friction during movement by the calcaneal tendon is minimised by what structures?
The subcutaneous calcaneal bursa and the deep calcaneal bursa.
What are the muscles of the superficial posterior compartment of the leg?
Gastrocnemius
Plantaris
Soleus
Origination, insertion, action and innervation of gastrocnemius.
Originates from the lateral femoral condyle and the medial head from the medial femoral condyle.
Inserts onto the calcaneal tuberosity.
Plantarflexion of the foot. Also assists in knee flexion as it crosses the knee.
Innervated by tibial nerve.
Origination, insertion, action and innervation of plantaris.
Originates from the lateral supracondylar line of the femur.
Inserts onto the calcaneus.
Plantarflexor. Not very functionally important. Also weak flexion of knee since it crosses the knee.
Innervated by tibial nerve.
Origination, insertion, action and innervation of soleus.
Originates from the solar line of the tibia and the proximal fibula.
Inserts onto the calcaneal tuberosity via the achilles tendon.
Plantarflexion and most powerful plantarflexor!
Innervated by tibial nerve.
Which are the four muscles of the deep posterior compartment of the leg?
Popliteus
Tibialis posterior
Flexor digitorum longus
Flexor hallucis longus
Origination, insertion, action and innervation of popliteus.
Originates from the lateral condyle of the femur and the posterior horn of the lateral meniscus.
Inserts onto the tibia proximal to the soleal line.
Laterally rotates the femur on the tibia unlocking the knee joint so that flexion can occur.
Innervated by the tibial nerve.
Origination, insertion, action and innervation of tibialis posterior.
The deepest of the four muscles.
Originates from the interosseous membrane between the tibia and fibula and from the posterior surfaces of the two bones.
Inserts onto the plantar surface of the navicular and medial cuneiform bones as well as the plantar surface of metatarsals 2-4.
Inverts and plantarflexes the foot. Maintains the integrity of the medial arch of the foot.
Innervated by the tibial nerve.
Origination, insertion, action and innervation of flexor digitorum longus.
Located posteromedially.
Between tibialis posterior and flexor hallucis longus.
Originates from the medial surface of the tibia.
Divides into four tendons that insert onto the base of the distal phalanx of each of the lateral four digits.
Flexes the lateral four toes.
Assists in plantarflexion of ankle and assists in inversion of midfoot.
Innervated by the tibial nerve.
Origination, insertion, action and innervation of flexor hallucis longus.
Located posterolaterally.
Between flexor digitorum longus (and tibialis posterior artery, tibial vein, tibial nerve) and calcaneal tendon.
Originates from the posterior surface of the fibula.
Inserts onto the plantar surface of the base of the distal phalanx of the great toe.
Flexes the great toe. Assists in plantarflexion of the ankle and assists in inversion of the midfoot.
Innervated by the tibial nerve.
What is the root value of the tibial nerve?
L4-S3.
In total, which nerves does the tibial nerve supply?
Posterior thigh: Long head of biceps femoris Semimembranous Semitendinous Hamstring component of adductor magnus
Superficial posterior compartment of the leg:
Gastrocnemius
Soleus
Plantaris
Deep posterior compartment of the leg: Flexor digitorum longus Flexor hallucis longus Popliteus Tibialis posterior
What are the sensory branches of the tibial nerve?
The medial sural cutaneous nerve
Medial calcaneal branches
Medial plantar nerve
Lateral plantar nerve
Which nerve does the tibial nerve arise from?
Sciatic nerve.
What nerve innervates the anterior compartment of the leg?
The deep peroneal (fibular) nerve.
What nerve innervates the lateral compartment of the leg?
The superficial peroneal (fibular) nerve.
What nerve innervates the superficial posterior compartment of the leg?
The tibial nerve.
What nerve innervates the deep posterior compartment of the leg?
The tibial nerve.
Where does the tibial nerve arise and where does it end up?
Arise from the sciatic nerve at the apex of the popliteal fossa. It then gives of branches into the superficial posterior compartment of the leg and also branches into the deep posterior compartment of the leg.
It divides into medial and lateral plantar nerves to supply the sole of the foot in a cutaneous manner.
What are the sensory branches of the tibial nerve?
SCPL: Medial sural cutaneous nerve Medial calcaneal branches Medial plantar nerve Lateral plantar nerve
What is the root value of the common peroneal fibular nerve?
L4-S2.
What muscles does the common peroneal fibular nerve innervate?
The anterior and lateral compartments of the leg. The common fibular will then split up into deep fibular and superficial fibular where the superficial will supply the lateral compartment and the deep fibular will supply the anterior compartment of the leg.
What cutaneous parts does the common fibular innervate?
Supplies the skin of the upper lateral leg and the superficial fibular and deep fibular supply the inferior lateral part of the leg and dorsal part of the foot except for 5th metatarsals and phalanges.
What is the root value of he superficial peroneal fibular nerve?
L4-S1
Root value of the deep peroneal fibular nerve.
L4-L5
What artery is the deep peroneal fibular nerve adjacent to?
The anterior tibial artery. (Supplies the anterior compartment of the leg so this makes sense)
What does the sural nerve supply?
It isn’t of great use and supplies the skin over the lateral border of the foot. It can be harvested for use in reconstructive surgery instead since there is just a tiny loss of sensation.
What are the main arteries in the leg?
Popliteal artery -> Which will divide into the: Anterior tibial artery Tibioperoneal trunk -> The tibioperoneal trunk then divides into: Posterior tibial Peroneal fibular arteries.
What does the anterior tibial artery supply?
Arise from the popliteal artery.
The anterior compartment and also the dorsum of the foot as it becomes the dorsals pedis as it cross the ankle.
What does the posterior tibial artery supply?
Arises from the tibiofibular trunk and supplies the posterior compartment of the leg.
Also supplies the plantar surface of the foot as it divides into medial and lateral plantar arteries.
What is the arrangement of the structures behind the medial malleolus? (Medial to lateral)
Tom, Dick, And Very Nervous Harry: Tibialis posterior Flexor Digitorum longus tendon Posterior tibial artery Posterior tibial vein Tibial nerve Flexor Hallucis longus
What does the fibular (peroneal) artery supply?
The lateral compartment of the leg and also some of the anterior compartment and the fibular. - (peroneus fibularis brevis and peroneus fibularis longus)
(Does not run in the lateral compartment!!)
What is the dorsals pedis artery?
A continuation of the anterior tibial artery that supplies the dorsum of the foot.
What are the four pulses that can be palpated in the lower limb? Where can they be found?
Femoral artery pulse found in the femoral triangle.
Popliteal artery pulse found in the popliteal fossa.
Dorsalis pedis artery pulse found by palpating the dorsum of the foot immediately lateral to extensor hallucis longus tendon.
Posterior tibial artery pulse which can be palpated in the tarsal tunnel below and behind the medial malleolus.
What aids venous return in lower limbs?
Walking by using muscles. The contraction aids venous return.
Since the veins are usually accompanied by arteries the pulsation of the arteries will aid venous return as well.
What is the main venous structure in the foot? What does it drain into?
Dorsal venous arch which drains into the great and small saphenous veins medially and laterally respectively.
What are the anterior tibial veins?
A collection of accompanying veins of the dorsalis pedals which continues in the leg as the venae comitantes of the anterior tibial artery. Provide drainage for the anterior compartment.
There is another venous structure in the foot, which? What does it drain into?
The plantar venous arch which branches into medial and lateral plantar veins. The medial and lateral plantar veins form the venae comitantes of the posterior tibial artery also known as the posterior tibial vein. Ascends together with the posterior tibial artery in the deep posterior compartment of the leg and drain the deep and superficial posterior compartments of the leg.
What is the venae comitantes of the peroneal fibular artery?
It is sometimes referred to as the peroneal fibular vein and it drains into the posterior tibial vein which in its turn unites with the anterior tibial vein to form the popliteal vein. Popliteal vein then enters the thigh and becomes the femoral vein instead.
What is the popliteal fossa?
A diamond-shaped landmark where a lot of structures pass through.
What are the borders for the popliteal fossa?
The superomedial border which is by semimembranous muscles
The superolateral border which is by the biceps femurs
The inferomedial border which is by the medial head of the gastrocnemius
The inferolateral border which is by the lateral head of the gastrocnemius
What is the floor of the popliteal fossa formed by?
The popliteal surface of the femur, the posterior surface of the knee joint capsule and the oblique popliteal ligament and the popliteus muscle.
What is the roof of the popliteal fossa formed by?
It is made up of two layers which are the popliteal fascia and the popliteal skin.
What structures passes through the popliteal fossa?
Popliteal artery and vein
Short (small) saphenous vein (drains into popliteal vein)
Tibial nerve and medial sural cutaneous branch
Common peroneal (fibular) nerve and lateral sural cutaneous branch
Popliteal lymph nodes
What is the calcaneal tendon?
Also called the achilles tendon that is formed by the blending of tendons from the superficial muscles of the posterior compartment. Inserts onto the calcaneus on the calcaneal tuberosity.
Two associated bursae.
