Leg and Foot Flashcards
What is a major difference between the bones of the arm and the bones of the leg
What is the osteology of the tibia and fibula?
No suppination or pronation of leg bones - stay in the same position and are fairly stable. Much more fixed joint without as much rotational aspect. Additionally the knee joint is just tibia and femur - the fibula is not really involved at all.
Middle of the fibula not really needed because muscles that insert superiorly and inferiorly stabilize the two joints already. So often the middle of the tibula can be used for bone grafts.
Fibula only has two parts: head and the lateral maleolus
What spaces are created by the interosseous membrane and what structures run through them?
Anterior tibial artery comes through the superior gap to get to the anterior compartment
Superior gap provides communition between the anterior tibial artery and the fibular artery.
What are the tarsal bones of the foot and how many are there?
What other important structures surround the tarsals?
7 tarsal bones
Sustentaculum talus: Sheet of bone extends out from the calcaneus and provides platform for the talus to sit on
Articulations: Tendon of flexor hallucis longus runs along the sustentaculum and provides additional support.
What are the metatarsals of the foot and their components? How many are there?
5
How many phalages are there in the foot?
How many bones are in the foot all together?
14 bones
(14 + 5 + 7)2 =
What are the different joints of the foot?
Ankle joint primarily based on the fibula and tibula making a “U” shape which the talus sits in-between.
What joints make up the arch of the foot?
What causes flat feet?
The arch is maintained by muscle tendons and ligaments.
Long plantar and short plantar ligament maintain the longitudinal aspects of the arch - extending off the calcaneous anteriorly to go up to the bases of the metatarsal.
Spring ligment provides angular support.
Arch support is also provided by tendons
Weakening of these ligaments causes flat feet.
What is the cutaneous innervation of the leg and foot and what are the triutary nerves?
Saphenous nerve comes off the femoral nerve and runs medially along the leg with the great saphenous vein.
On posterior side have lateral sural cutenous nerve with medial communicating branch that becomes the sural nerve proper (branches of the tibial nerve)
Have superficial fibular and deep fibular nerve. The superficial fibular nerve comes off the common fibular and does the lateral aspect of the anterior leg and the deep fibular nerve is going to primarily do muscles but does come down and innervates the skin between the first and second toes.
*Clinically relevant because if patient has pain in anterior leg can determine if the deep fibular nerve is involved by testing for loss of sensation between the first and seond toe.
Lateral plantar nerve and medial plantar nerve are the terminal branches of the tibial nerve and they do the bottom of the foot.
Label the cutaneous innervation and contributing nerve
Label the cutaneous innervation and contributing nerves
How are the dermatomes distributed below the waist and why?
Because limbs rotated medially they dragged the dermatomes around - produced lateral to medial pulling along the lower extremity.
All dermatomes center around the anus because gastrulation started at cloacal end.
What is the venous drainage structures of the foot and laeg?
Have dorsal venous arch on the dorsal side of the foot. From that arch of great saphenous running medially drains into the femoral nerve at the saphenous hiatus.
On the other side of the arch is a the small saphenous vein that runs posteriorly and drains into the popliteal vein
What are the crural fascia?
Intermuscular septums made of dense inrregular connective tissue that provide separation of different compartments
What are the different retinacula of the foot and what is their role?
They prevent the tendons from breaking loose and bowing out of the foot.
Flexor retinaculum is particularly important because of vessels running through it on the medial side of the ankle.
What muscles are in the anterior compartment of the leg and how are they innervated?
Largest muscle is the tibialis anterior muscle - powerful dorsal flexor.
2 extend the digits - 1 extends the big toe (extensor hallucis longus muscle) and 1 that extends all the other digits (extensor digitorum longus muscle)
Not everyone has fibularis tertius muscle
All supplied by deep fibular nerve - also does skin between first and second toe
What muscles are in the lateral compartment of the leg and how are they innervated?
Fibularis longus muscle comes down around the lateral malleolus, under the arch of the foot to support it.
The fibularis brevis deep to that is going to come down around the lateral malleolus and insert on the fifth metatarsal.
Fibular nerve divides into superficial branch which does the lateral compartment and the deep branch which does the anterior compartment and between the toes.
Fibularis tertius muscle comes off one of the extensors and runs to the fifth metatarsal
How are the different muscular compartments of the leg innervated?
What muscles are in the superficial posterior compartment?
What muscles are in the deep posterior compartment?
How are they innervated?
3 muscles in superficial:
- Gastrocnemius m. (calf muscles - lateral and medial head join to form calcaneal tendon “achiles”)
- Soleus m. (flat muscle deep to the gastrocneumis, heads attach to the calcaneal tendon as well)
- Plantaris m. (small wimpy muscle that arises at fibula and goes into the calcaneal tendon; long tendon that crosses back of thigh)
4 muscles in deep:
- Poptileus muscle (floor of the popliteal fossa - helps lock and unlock the knee; origin is more distal and insertion is more proximal when fixed)
- Tibialis posterior muscle
- Flexor digitorum longus muscle
- Flexor hallucis longus muscle ( starts on lateral side, goes down, over sustentaculum talus and runs off to the big toe)
All innervated by tibial nerve which comes across ankle and divides into two terminal branches - the medial and lateral plantar nerves which do the bottom of the foot skin.
In what order the tendons go around the lateral malleolus?
Tibial artery and tibial nerve run right between the digitorum and the hallucis.
Harry running deeper underneath that sustentaculum talus
What are the muscles of the dorsal aspect of the foot and what is their innervation?
Innervated by deep fibular which then goes down and does inbetween the 1st and 2nd toe skin.
What is the very first layer of the plantar foot?
What is the next layer of the plantar foot?
1st layer: Plantar aponeurosis
2nd layer: 2 abductors with a flexor inbetween
Flexor digitorum brevis does the same thing as digitorum superficialis in the hand and splits, allowing the longus to go through.
What is the second layer of the plantar foot? What is this layer called?
“Tendinous layer”
Have two tendons: flexor hallucis longus tendon and flexor digitorum longus tendon coming out of the flexor digitorum brevis to insert on the distal phalanx.
2 muscles are associated with the tendons.
Quadratus plantae puts pull on flexor digitorum which is more medial to make sure it pulls in proper alignment.
Lumbrical arise from the flexor digitorum longus tendon. 1st lumbrical innervated by medial plantar (from tibial nerve) and last 3 lumbrical innervated by the lateral plantar.
What is in the 3rd layer of the plantar foot?
2 flexors and an adductor
*No flexor digiti mini longus - really just the tendon of the digitorum longus and brevis, so can leave “brevis” off
Adductor hallucis muscle innervated by lateral plantar nerve (tibial nerve)
What is in the fourth layer of the foot?
Interosseus and tendons that support the arches
What is the plane of action in the foot - in relation to the interosseus?
What is the arrangment of interosseus and how many are on each side?
The second digit defines the interosseus motion
Don’t need to abduct the minimi or the halax because they have their own adductors
What does the medial and lateral plantar nerve innervate?
Medial only does 4 muscles - everything else by lateral plantar nerve
How does the popliteal fossa change as it moves towards the foot?
Popliteal artery runs through the popliteal fossa and then terminates as an anterior tibial artery and a posterior tibial artery.
Anterior tibial artery is going to go through interosseus membrane and do anterior compartment.
Posterior tibial artery is going to continue on down the leg with the tibial nerve and give off fibular artery that is going to do the lateral compartment.
5 genicular branches around the knee provide anastomoses around the knee joint.
How does the anterior tibial artery change as it moves towards the foot?
Anterior tibial artery comes through the interosseous membrane and runs down with the deep fibular - runs onto the dorsal aspect of the foot as the dorsalis pedis.
*Can pick up the pulse of the dorsalis pedis on top of the feet
What are the branches of the dorsal pedis artery?
What is the pathway of posterior tibial artery?
Gives a fibular branch which provides perforating branches to supply fibularis longus and brevis without going into the lateral compartment itself.
What is the pathway of the medial and lateral plantar arteries?
They follow the pathway of the nerves
What is the pathway of the plantar arch? What is its function?
Allows the lateral and medial plantar to communicate with eachother and they can communicate with the dorsalis pedis (where dorsal arch comes from) by perforating through. All three arteries have an anastomotic connection in the foot that allows for supply if one gets compromised.
What muscles are involved in standing?
What muscles are involved in walking?
What causes the patella tendon reflex?
Tap the muscle causes afferent nerve to got to the spinal cord and that muscle to contract - reflex arch
Why do femoral nerve injuries happen often? What are the consequences? How would the patient present?
Fibular nerve is superficially located and therefore can be damaged in trauma. Weakens muscles of the anterior and lateral compartment - can’t evert very well or dorsal flex.
Patient either drags toes or takes high steps.
Sensory loss over dorsal surface of the foot, lateral surface of leg, and if deep fibular affected - between first and second toe.
