The Anterior and Lateral Leg and Dorsum of the Foot Flashcards
What binds the fibula and the tibia together?
Interosseous membrane
What fascia entirely surrounds the muscles of the leg?
Deep fascia (crural)
What are the inter-muscular septa?
Extensions of the crural fascia that divide the leg into three compartments
What are the components formed from the inter-muscular septa?
- Anterior compartment
- Lateral compartment (small)
- Posterior compartment (large)
What compartment of the leg has a transverse muscular septum dividing it into superficial and deep?
Large posterior compartment
What vessel sits in the medial side of the leg in the subcutaneous tissue?
The great saphenous vein
What vessel sits posteriorly in the leg in the subcutaneous tissue?
The small saphenous vein
What is the main function of the interosseous membrane?
To resist the downwards pull of muscles attached to the fibula
What direction do the fibres in the interosseous membrane travel?
Inferolaterally
Name the only muscle in the leg that pulls the fibula upwards
Biceps femoris
What two joints are formed between the fibula and the tibia?
Superior and inferior tibiofibular joints
What type of joint are the tibiofibular joints?
Plane synovial joint
What areas of bone are the tibiofibular joints between?
- The head of the fibula
- Inferior aspect of the of the lateral condyle of the tibia
What ligaments cover the tibiofibular joint?
Anterior and posterior ligaments
Name the muscles in the anterior compartment of the leg
- Tibialis anterior
- Extensor digitorum longus
- Peroneus tertius
- Extensor hallucis longus
Name the muscles in the lateral compartment of the leg
- Peroneus longus
- Peroneus brevis
What compartment of the leg contains muscles that are all extensors of the ankle joint?
Anterior compartment
What compartment of the leg contains muscles that are involved with the eversion of the foot?
Lateral compartment
What is eversion?
Where the foot is twisted so the sole faces slightly laterally
What is the proximal and distal attachment of the peroneus longus muscle?
Proximal - the head and upper 2/3 of the lateral side of the femur
Distal - the base of the 1st metatarsal and medial cuneiform bone
What nerve supplies the lateral compartment?
The superficial peroneal nerve (L5, S1, S2)
What is the proximal and distal attachment of the peroneus brevis muscle?
Proximal - the inferior 2/3 of the lateral surface of the fibula
Distal - the tuberosity on the lateral side of the base of the 5th metatarsal
Do the muscles of the lateral compartment pass posterior or anterior to the lateral melleolus?
Posterior
What is the name of the small ridge on the calcaneus bone of the foot that each of the peroneus tendons run either side of? Which tendon is anterior and which is posterior?
- Peroneal trochea of the calcaneus
- Peroneus brevis runs anteriorly
- Peroneus longus runs posteriorly
What do all the muscles of the anterior compartment contribute to?
Dorsiflexion
What nerve supplies all the muscles of the anterior compartment?
The deep peroneal nerve (L4, L5)
What are the proximal and distal attachments of the tibialis anterior muscle?
Proximal - the lateral condyle of the tibia, the superior 1/2 of the lateral tibial surface and the interosseous membrane
Distal - the medial and inferior surfaces of the median cuneiform ad the base of the 1st metatarsal
What are the proximal and distal attachments of the extensor digitorum longus?
Proximal - the lateral condyle of the tibia, the superior 3/4 of the medial surface of the fibula and the interosseous membrane
Distal - the middle and the distal phalanges of the lateral four digits
What happens to the extensor digitorum longus muscle when it enters the foot?
Divides into 4 branches
What is the main action of the extensor digitorum longus muscle?
Extension of the lateral 4 toes
What are the proximal and distal attachments of the peroneus tertius?
Proximal - the inferior 1/3 of the anterior fibula and the interosseous membrane
Distal - the dorsum of the 5th metatarsal close to the base
What is the main action of the peroneus tertius?
Contributes to dorsiflexion of the ankle and eversion of the foot
What is the main action of the externsor hallucis longus?
Extension of the big toe
What are the proximal and distal attachments of the extensor hallucis longus?
Proximal - the middle anterior surface of the fibula and the adjacent interosseous membrane
Distal - the dorsal aspect of the distal phalanx of the big toe
What is the extensor retinaculum?
A thickening of fascia over the dorsum of the foot that help keep the tendons in place
Where is the superior extensor retinaculum found?
Found in the dorsum of the foot and runs from the anterior border of the tibia to the lower end of the fibula
Explain the structure of the inferior extensor retinaculum
- Is a Y shaped structure found in the dorsum of the foot
- Attaches to the calcaneus bone laterally and extends to the medial malleolus
Where do all of the muscles of the dorsum of the foot have their proximal attachment?
The superior surface of the calcaneus
What two muscles are found in the dorsum of the foot?
- Extensor hallucis brevis
- Extensor digitorum brevis
What muscle extends the hallux?
Extensor hallucis brevis
What muscle helps to extends digits 2-4 of the foot?
Extensor digitorum brevis
What is the distal attachment of the extensor hallucis brevis?
The base of the proximal phalanx of the hallux
What is the distal attachment of the extensor digitorum brevis?
The long extensor tendons of toes 2-4
What nerve innervated the extensor hallucis brevis and the extensor digitorum brevis?
The deep peroneal nerve (L5-S1)
What are the terminal branches of the sciatic nerve and where do they appear?
Splits at the apex of the popliteal fossa and gives two branches - the tibial nerve and the common fibular/peroneal nerve
What are the nerve roots of the tibial nerve?
L4-S3
What are the nerve roots of the common fibular/peroneal nerve
L4-S2
What are the terminal branches of the common fibular/peroneal nerve?
- Superficial fibular/peroneal nerve
- Deep fibular/peroneal nerve
What nerve supplies the peroneus longus and peroneus brevis muscles?
The superficial fibular/peroneal nerve
What happens to the superficial fibular/peroneal nerve as it travels down the leg?
Continues distally as a cutaneous nerve that will supply most of the skin of the dorsum of the foot and the anterolateral aspect of the leg
How does the deep peroneal/fibular nerve reach the anterior compartment?
By piercing through the extensor digitorum longus
What nerve supplies the muscles of the anterior compartment?
Deep fibular/peroneal nerve
What happens as the deep fibular/peroneal nerve travels down the leg?
- Runs down the interosseous membrane to anteriorly pass over the ankle to supply the two muscles on the dorsum of the foot
- Ends as a cutaneous nerve supplying the skin between the first and second toe
What are the arteries of the leg terminal branches of?
The popliteal artery
What are the terminal branches of the popliteal artery?
The anterior and posterior tibial arteries
How does the anterior tibial artery enter the anterior compartment?
By piercing through the interosseous membrane
What does the anterior tibial artery supply?
The anterior compartment
What artery supplies the muscles of the lateral compartment and what is it a branch of?
- The fibular artery
- Is a branch of the posterior tibial artery
What does the anterior tibial artery become as it crosses the ankle joint?
The dorsalis pedis artery
What are the branches of the dorsalis pedis artery and explain their structure?
- Lateral tarsal artery
- Deep plantar artery
- Arcuate artery
- Dorsalis travels down the medial aspect of the foot and is connected to the lateral tarsal artery via the arcuate artery, forming a triangle
What branch of the dorsalis pedis artery dives between the first and second metatarsals to anastomose with arteries that supply the sole of the foot
The deep plantar artery
What artery of the foot runs along the metatarsals to anastomose with the lateral tarsal artery?
Arcuate artery
What arteries branch off of the arcuate artery?
Metatarsal and digital arteries