Sem 2 - L - Posterior Leg & Ankle Joint - Superficial/deep muscles, Flexor retinaculum, posterior arteries, tibial nerve, ligaments Flashcards
What is the oblique line visible on the posterior surface of the tibia known as? What is the area above this line for the attachment of which muscle known as?
The oblique line on the posterior surface of the tibia is known as the soleal line Above the soleal line lies the popliteal area which is where the popliteus muscle will lie
There are 3 superficial and 4 deep muscles in the posterior compartment of the leg Where do all the superficial muscles insert? what do the tendons of the deep muscles pass behind to reach the plantar surface of the foot? (except which muscle)
All the superficial muscles insert on the posterior surface of the calcaenous via the tendocalcaneous (calcaneal tendon) The tendons of the deep muscles pass behind the medial malleolus of the tibia to reach the plantar surface of the foot (except the popliteus)
What are the muscles of the superficial compartment of the leg? What is their common insertion? What is their nerve supply?
Gastrocnemius, soleus and plantaris Common insertion - tendocalcaneous Nerve supply - tibial nerve (S1,2 roots)
What is the origin of the gastrocnemius and what is its function?
- Medial head attaches to the popliteal surface of femur superior to medial condyle
- Lateral head slightly lower down at the lateral aspect of the lateral condyle of the femur
Function - plantarflexion of the ankle, and flexion of the knee
What is the attachment of the plantaris muscle and what is its function? What is special about this muscle?
Plantaris is not present in about 10% of the popluation
It attaches from the lateral supracondylar line of femur (proximal to the lateral head of the gastrocnemius) and travels on top of the soleus - very long tendon
Assists in plantarflexion of the ankle
The deepest of the superficial posterior compartment muscles is the soleus What is the origin of the soleus muscle?
Soleus attaches to the soleal line of tibia, upper 1/3rd of posterior fibula and a tendinous arch between these two bony attachments to narrow into the tendocalcaneous
It plantarflexes the ankle joint
What are the deep muscles of the posterior compartment of the leg?
Popliteus Flexor digitroum longus Tibialis posterior Flexor hallucis longus
What is the attachment of the popliteus?
Popliteus - attaches from the lateral condyle of the femur (pit for popliteus) and lateral mensicus to the popliteal area of the tibia above the soleal line
When the knee is in full extension, the femur slightly medially rotates on the tibia to lock the knee joint in place. What is the nerve supply to the popliteus and what is its function?
Popliteus is innervated by tibial nerve (L4,5 S1) When the popliteus contracts it pulls on its proximal attachment at the lateral condyle of the femur (also attaches to lateral mensicus) and ‘unlocks’ the knee by laterally rotating the femur on the fixed tibia
State the attachment, nerve supply and function of the popliteus
- Attachment - lateral condyle of the femur (popliteal pit) and lateral meniscus to the popliteal area of the tibia (above the soleal line)
- Nerve supply - tibial nerve (L4,5, S1)
- Function - laterally rotates the femur on fixed tibia unlocking the knee joint
What is the attachment of the flexor digitorum longus? (it is the most medial of the deep compartment muscle bellies)
Flexor digitorum longus attaches from posterior surface of tibia to the base of the distal phalnyx of digits 2-5
What is the nerve supply of the flexor digitorum longus and what is its function?
Flexor digitorum longus supplied by tibial nerve L5,S1,S2 Function - Flexes lateral 4 digits and weakly plantarflexes the ankle
State the attachment, nerve supply and function of the FDL
Flexor digitorum longus
- Attachment - posterior surface of tibia to the base of the distal phalnyx of digit 2-5
- Nerve supply - Tibial nerve - L5, S1, S2
- Function - Flexes lateral 4 digits and weakly plantarflexes the ankle
State the attachment of the flexor hallucis longus
Attaches from the posterior surface of the fibula to the base of the distal phalnyx of the hallux
What is the nerve supply to flexor hallucis longus and what is its function?
Flexor hallucis longus supplied by tibial nerve (L5, S1, S2) Function - Flexes the hallux and weakly plantarflexes the ankle
State the attachment, nerve supply and function of the flexor hallucis longus
Flexor hallucis longus
- Attachment - posterior surface of fibula to base of distal phalnyx of the hallux
- Nerve supply - Tibial nerve (L5,S1,S2)
- Function - Flexes the hallux and weakly plantarflexes the ankle
Why is the flexor hallucis longus abnormally large for a muscle supplying a single digit?
This is because we push off from our big toe during walking and therefore the flexor of the big toe needs to be very strong to do this - big muscle belly
Between the muscle bellies of the FDL and FHL lies the tibialis posterior State the proximal attachment of the tibialis posterior?
Tibialis posterior attaches proximally between the FDL and FHL from the posterior surface of the tibia and fibula and interosseous membrane
The distal attachment of the tibialis posterior is very complicated as the tendon of this muscle fans out once in the sole of the foot Try and state the insertion of the tibialis posterior tendon
Inserts onto the tuberosity of the navicular, 3 cuneiforms, cuboid bone, sustentaculum tali of calcaenous (means shelf for talus), base of 2nd, 3rd and 4th metatarsals
State again the attachments of the tibialis posterior Include nerve supply and function
TP attaches to posterior surface of the tibia and fibula and interosseous membrane and inserts onto the tuberosity of the navicular, all three cuneiforms, cuboid bone, sustentaculum tali of calcaneous and base of metatarsals 2-4
- Innervation - Tibial nerve - L4,5
- Function - plantarflexion of ankle and inversion of foot
What grooves are formed by the tibialis posterior and FHL tendons?
- Tibialis posterior tendon forms a groove on the posterior aspect of the medial malleolus
- The flexor hallucis longus grooves the posterior surface at the lower end of the tibia and grooves the talus
What are all the tendons of the deep posterior compartment of the leg held in place by and what is the attachment of this structure?
All the tendons are held in place by the flexor retinaculum of the foot - attaches from medial malleolus to calcaneous
Why is there quite a gap between the flexor digitorum longus and flexor hallucis longus tendons passing deep to the flexor retinaculum?
What mnemonic can be used to help remember the order of the tendons and neurovasculature?
Between the FDL and FHL tendons is the neurovasculature to foot
- Tom Dick (And Very Naughty) Harry
- Tibialis posterior tendon flexor
- flexor Digitorum longus tendon
- tibial Artery
- Venae commitantes
- tibial Nerve
- flexor Hallucis longus tendon
Once the tibial nerve and posterior tibial artery pass deep to the flexor retinaculum of the foot, what do they temrinate as? What do they travel between at the ankle joint?
They terminate as the medial and lateral plantar nerves and arteries in the foot The tibial nerve and posterior tibial artery travel between FDL and FHL at the ankle joint
What is the cutaneous nerve supply to sole of the foot?
Heel - calcaneal branches from the tibial nerve
Medial three and a half digits - medial plantar nerve
Lateral one and a half digits - lateral plantar nerve
Dermatomal innervation of the lower limb is also important State the dermatomes to: Little toe and lateral foot Middle three toes and dorsum/plantar of foot in this stripe Big toe and medial foot
Little toe and lateral foot - S1
Middle three toes and dorsum/plantar of foot in this stripe - L5
Big toe and medial foot - L4
What does the axial line of dermatomes refer to?
The axial line of dermatomes refers to two adjacent dermatomes not represented by immediately adjacent spinal levels
Which ligaments strengthen the inferior tibiofibular joint?
The anterior and posterior tibiofibular ligaments
The interosseous tibiofibular ligament is continous with the interosseous membrane and helps to strengthen the inferior talofibular joint
- What type of joint is the inferior tibiofibular joint?
- What forms the articulations in this joint?
- What movement is allowed in this joint?
- What ligaments help to strengthen this joint?
- Inferior tibiofibular joint is a syndesmoses - type of fibrous joint - between fibular notch of distal tibia and distal fibula
- Slight movement to accommodate the wedging of the trochlea of the talus during ankle dorsiflexion
- Anterior, posterior and interosseous tibiofibular ligaments help to strengthen the joint
What articulating surfaces form the ankle joint and what type of joint is it?
The distal ends of the tibia and fibula form what is known as the mallolular mortise (distal end of tibia plus inner surface of medial and lateral malleolus) which allows for the insertion of the trochlea of the talus
The ankle joint is a synovial hinge joint
What type of movements does the ankle joint allow for and what degree of these movements is allowed?
Which movement makes the joint less stable?
The ankle joint allows for 20-30 degrees of dorsiflexion AND 30-50 degrees of plantarflexion
When the ankle is plantarflexed and the posterior part of the talus is held in the malleolar mortise, the ankle joint is less stable
Pic shows The talus. It is broad anteriorly, which strengthens the joint during dorsiflexion. As the ankle joint is a synovial joint, it will have a joint capsule What are the attachments of the ankle joint capsule?
The ankle joint capsule attaches to the articular margins of the ankle and extends anteriorly onto the neck of the talus
Where is the ankle joint capsule weaker? What is it strengthened by?
The anle joint capsule is weaker anteriorly and posteriorly to allow for plantarflexion and dorsiflexion of the ankle
Medially and laterally, it is strengthened by the medial (deltoid) and lateral collateral ligaments of the ankle respectively
What are the attachments of the three ligaments making up the lateral collateral ligament of the ankle?
- Anterior talofibular - extends from the lateral malleolus to the neck of the talus
- Posterior talofibular - extends from the lateral malleolus to the lateral tubercle of the talus (posterior aspect)
- Calcaneofibular - extends from lateral malleolus to lateral surface of calcaenous
What ligaments make up the medial collateral ligament of the ankle? State the other name for this ligament
Where do they all arise?
Deltoid ligament
- * Anterior tibiotalar
- * Tibionavicular
- * Tibiocalcaneal
- * Posterior tibiotalar
They all fan out from the medial malleolus of the tibia
State all the ligaments involved in the lateral and medial collateral ligaments of the ankle
Medial collateral ligament
- Anterior tibiotalar ligament
- Tibionavicular ligament
- Tibiocalcaneal ligament
- Posterior tibiotalar ligament
Lateral collateral ligament
- Anterior talofibular ligament
- Posterior talofibular ligament
- Calcaneofibular ligament
- Which tendons run anterior to the anle joint?
- Which vein runs anterior to medial malleolus?
- Which tendons run posterior to the medial malleolus?
- Which tendons run posterior to the lateral malleolus?
- Which vein run posterior to lateral malleolus?
- Anterior to ankle - Tibialis anterior, EHL, EDL peroneus tertius
- Vein anterior to medial malleolus - great saphenous vein
- Posterior to medial malleolus - tibialis posterior, FDL, FHL
- Posterior to lateral malleolus - peroneus longus and brevis
- Vein posterior to lateral malleolus - short saphenous vein
