Week 3 L4: The leg, ankle and foot Flashcards
What bones form the ‘talocrural’ or ankle joint?
-medial and lateral malleolus from distal tibia and fibula respectively form a socket (‘mortise’) for the talus
What movements are possible at the ankle joint?
- Extension (dorsiflexion - dorsum of foot comes up towards leg)
- Flexion (plantar flexion - - toes point towards ground)
Where is the subtalar joint?
just beneath the talar joint - lies between the talus and the calcaneum (heel bone)
What movements occur at the subtalar joint?
- Inversion (inwards)
2. Eversion (outwards)
When is the ankle joint most stable?
in dorsiflexion - because the anterior part of the trochlear of the talus moves betweeen the malleoli which spreads the tibia and fibula slightly, increasing their gap on the talus
What are the medial ligaments of the ankle joint attached to?
medial malleolus
What is another word for the medial ligament of the ankle and what does it attach to?
- also called deltoid ligament
- attaches to talus, navicular and calcaneus
In the foot, what are the names of the 3 groups of bones?
- Tarsal bones
- Metatarsal bones
- Phalanges (big toe has 2, toes 2-5 have 3)
What are the names of the 7 tarsal bones?
- Calcaneum (heel bone)
- Talus
- Navicular
- Cuboid
- Medial cuniform
- Intermediate cuniform
- Lateral cuniform
Which is medial and which is lateral out of cuboid and navicular?
navicular is medial
cuboid is lateral
Where do the metatarsals articulate with the phalanges?
metatarsal phalangeal joints
Where are the interphalangeal joints?
joints between phalanges
What movements are possible at the toes?
- flexion
- extension
- abduction
- adduction
At what joints in the foot is there limited abduction and adduction?
at the MTPJs
What are the names of the 3 boney arches that help to distribute weight, absorb shock and increase flexibility of the foot?
- lateral longitudinal ligament
- transverse ligament
- medial longitudinal ligament
What are the 3 muscle compartments of the leg?
anterior, posterior and lateral
What is compartment syndrome?
When there is excessive swelling within a closed fascia-bone space, increasing the pressure and restricting the blood flow to the area, damaging the muscles and nearby nerves
What do the anterior compartment muscles do?
extensors of ankles and toes
Which nerve innervates the anterior compartment muscles?
deep fibular nerve (branch of the common fibular)
What are the names of the 3 muscles in the anterior compartment?
- Tibialis anterior
- Extensor digitorum longus
- Extensor hallucis longus
Explain the root of the extensor digitorum longus
comes from the lateral tibial condyle and fibula, inserts on the ankle joint and inserts on digit 2-5
Explain the attachments of the tibialis anterior
Originates from the lateral surface of the tibia, attaches to the medial cuneiform and the base of metatarsal
Explain the attachments of the extensor hallucis longus
- arises from the fibula
- attaches to the distal phalanx of big doe
What is the function of:
- Tibialis anterior
- Extensor hallucis longus
- Extensor digitorum longus
- Extension (dorsiflexion) of foot and inversion of foot
- Extension (dorsiflexion) of foot and big toe
- Extension of the lateral four toes and foot
Which nerve innervates the posterior compartment of the leg?
tibial nerve
There are 2 groups of muscles in the posterior compartment. What are the names of the 3 muscles in the superficial group
- Gastrocnemius
- Soleus
- Plantaris
Where do all 3 tendons in the posterior compartment converge onto?
they come together to form the calcanea (“achilles”) tendon which insert onto the calcaneum (heel bone)
Where does the gastrocnemius originate?
2 heads:
medial and lateral femoral condyles
Where does the soleus originate?
origin of soleal line
What is the function of the posterior compartment muscles?
flexion (plantar flexion of ankle) - toes towards ground
Which superficial posterior compartment muscle forms the inferior boundary of the popliteal fossa?
gastrocnemius
Which superficial posterior compartment muscle is deep to gastrocnemius?
soleus
What are the names of the 4 deep muscles in the posterior compartment?
- Popliteus
- Tibialis posterior
- Flexor digitorum longus
- Flexor hallucis longus
Where does the popliteus originate and insert and what is its function
Origin: Lateral femoral condyle
Insert: Posterior proximal tibia
Function: unlocks the knee and gives lateral rotation