Sievert: Posterior Leg and Foot Flashcards Preview

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Flashcards in Sievert: Posterior Leg and Foot Deck (72)
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What will the main difference between damaging the median nerve at the wrist vs the elbow?

At the wrist: primarily affects thenar compartment muscles, leading to thumb derotation, but a normal hand. This is called ape hand. At the elbow: you lose deep compartment muscles due to the deep branch of the median nerve. So, you will get papal blessing (thumb derotated, but also get straightening of 2 fingers)


What are the lateral and medial malleolus? What is significant about these structures? On which bone is the lateral ma

bumps on the tibia and fibula at the ankle; these structures are important, because muscles that pass anterior are dorsiflexors and muscles that pass posterior are plantarflexors.


Together the two bones of the leg make a nice articular surface for the (blank) bone of the foot. This surface is wider anteriorly and narrow posteriorly. The articular surface is held together by the anterior and posterior (blank) ligaments.

talus; tibiofibular


How is the interosseous membrane different in the leg than in the forearm?

In the leg, the interosseous membrane does not have predominant fibers oriented in a certain direction. In the forearm, the interosseous membrane is designed to transmit force from the radiocarpal joint up to the elbow.


What is the main supporting bone of the leg?



What is the fibula primarily used for?

helps hold the ankle joint together; serves as an attachment site for muscles


How many compartments are there in the leg? What are they? What surrounds each compartment?

four compartments; anterior compartment, lateral compartment, deep posterior, and superficial posterior compartment; each compartment is surrounded by a crural fascia (deep fascia of the leg)


What is contained in the anterior compartment?

extensor muscles: tibialis anterior, extensor hallucis longus, extensor digitorum longus
anterior tibial artery and veins
deep fibular nerve


What is contained in the lateral compartment?

fibularis longus
fibularis brevis
superficial fibial nerve


What is contained in the deep posterior compartment?

deep flexor muscles: flexor digitorum longus, tibialis posterior, flexor hallucis longis, popliteus
posterior tibial artery and veins
tibial nerve
fibular artery and veins


What is contained in the superficial posterior compartment?

superficial flexor muscles: soleus, gastrocnemius, plantaris (tendon)


Why are there two neurovascular bundles in the deep posterior compartment? Where do both of the bundles come from?

the fibular vascular bundle is making its way over to the lateral compartment; both are derived from the tibfib trunk


What is notable about the plantaris tendon?

it tears easily and may lead to spontaneous contraction


The gastrocnemius and soleus are both powerful (blank). They have a mechanical advantage due to their attachment to the (blank), which is as far away from the axis of rotation as possible!

plantarflexors; Calcaneal tendon


Does the gastrocnemius cross the knee joint? Does the soleus?

Yes, so the gastroc has action at the knee joint; no, the soleus only works at the ankle


If you plantarflex from an extended knee, what muscles are you using? If you plantarflex from a sitting position, what muscle are you using?

gastroc and soleus; soleus only (gastroc taken out of the picture - when flexing the knee, can't use gastroc to plantarflex)


What is the action of the muscles of the deep posterior compartment?

plantar flexors and inverters in addition to their obvious named action because they pass posterior to the medial malleolus


Which compartment is the popliteus located in? What action does it serve?

proximal deep compartment; serves to unlock the knee joint


What is the action of the muscles in the anterior compartment? Which of these muscles is a good invertor?

dorsiflexion in addition to their namesake functions; tibialis anterior is a good invertor


What two functions does the extensor hallucis longus perform?

dorsiflexion, extension of big toe


What two functions does the extensor digitorum longus perform?

dorsiflexion, extension of all other toes (besides big toe)


What does the tibialis anterior muscle do?

in addition to being a powerful dorsiflexor, it is also a good invertor **crosses to the medial side of the foot


The ankle itself only flexes and extends, but there are joints that allow you to rotate the plantar surface of the foot inward or outward. What is this motion called? What are most sprains caused by?

rolling the ankle inward is eversion!!! the other direction is inversion; most sprains caused by inversion (rolling ankle)


What muscle of the anterior compartment is a powerful invertor due to its attachment to the medial foot?

tibialis anterior


What is a tiny muscle that comes off of the extensor digitorum longus that is kind of reminiscent of a lumbrical. It attaches to the 5th metatarsal. What is significant about this muscle?

fibularis tertius; this muscle has a clinical involvement in inversion sprains, because lots of tension is placed on this muscle when you roll your ankle, and this could cause the muscle to be torn off of the 5th metatarsal.


2 muscles of the lateral compartment? What is there action?

fibularis longus and brevis; they are posterior to the malleolus, so they are plantar flexors. They both attach to the lateral side of the foot, so they are evertors.


Which tendon/muscle of the lateral compartment wraps under the plantar aspect of the foot and forms a supportive sling with the tibialis anterior at the base of the 1st metatarsal?

fibularis longus


What supplies nerve innervation to the leg?

entirely sciatic nerve


What two nerves does the sciatic diverge into?

tibial component to the posterior compartment
fibular component to the anterior and lateral compartment


What does the fibular nerve bifurcate into? What does each branch supply?

a superficial and a deep component; the superficial gains access to the two muscles of the LATERAL compartment and then becomes cutaneous at the dorsum of the foot, the deep goes to the ANTERIOR compartment and also supplies the deep intrinsic muscles to the foot


Which nerve is most lateral in the popliteal fossa?

fibular nerve


What does the tibial nerve innervate?

Tibial nerve continues into the POSTERIOR compartment and gives off branches to deep and superficial muscles -- innervates the entire posterior compartment.


What are 2 important components of gait?

plantar flexion


What does loss of innervation to the anterior compartment cause? What will gait look like?

Loss of dorsiflexors, causing severe foot drop*** which is very evident. Before the swing phase is activated, have to dorsiflex to avoid dragging toe on the ground. If you lose common fibular or deep fibular to tibialis anterior – main dorsiflexor, you’ll drag your foot on the ground. You can compensate via a circumducting gait, or use a steppage gait where you lift the foot up high and step down slowly. Lots of varying gaits in order to accommodate.


What does loss of innervation to the posterior compartment cause?

Inability to plantar flex, or push off the ball of the foot. You will just have lots of dorsiflexion. You lose the added push of plantar flexion, so main affect is a SHORTER GAIT on the affected side.


When does the femoral artery become the popliteal?

after it passes through the adductor hiatus


The popliteal artery divides into what two branches? Where does each go?

anterior tibial: dives through the interosseus membrane to the front of the leg to supply the anterior compartment and continues onto the foot as the dorsalis pedis. It also supplies some of the lateral compartment through perforators.
tibfib trunk: supplies posterior compartment, and continues for a bit before dividing into the tibial and fibular. The fibular supplies some of the posterior and some of the lateral compartment by way of perforating branches.


How many retinacula are there for the foot? What are they?

superior extensor retinaculum
inferior extensor retinaculum
peroneal retinacula (2 which contain the lateral compartment tendons)
flexor retinaculum (which contains the deep posterior compartment tendons)


Which retinaculum holds the deep posterior compartment muscles in place?

flexor retinaculum


Are there intrinsic muscles on the dorsal side of the foot? What are they? What are they innervated by?

yes; extensor hallucis brevis and extensor digitorum brevis; innervated by the deep fibular nerve


What artery of the leg continues onto the dorsum of the foot and becomes the dorsalis pedis?

anterior tibial artery


What artery of the leg forms the plantar arch?

lateral plantar artery from the posterior tibial artery


What is significant about the common fibular nerve?

It wraps around the head of the fibula, and it is easy to damage this nerve and cause foot drop! Ex: crushed between a car!


The superficial femoral becomes the (blank) as it passes through the adductor hiatus. Popliteal artery gives off (blank) trunk (posterior tibial) posteriorly and anterior tibial, which is a short segment that dives thru the (blank) to the front of the leg. The tibfib trunk continues a ways and then divides into tibial and fibular artery. (blank) artery on the lateral side. (blank) goes down onto the foot to give dorsalis pedis.

popliteal artery; tibfib; interosseus membrane; fibular; anterior tibial


What artery goes into the foot laterally? What goes into the foot on the medial side?

fibular artery; posterior tibial artery


What does the posterior tibial divide into? Which artery gives off the plantar arch, which connects to the perforating branch of the dorsalis pedis?

medial and lateral plantar branches; lateral plantar artery


What artery goes into the foot laterally? What artery goes into the foot on the medial side?

fibular artery; posterior tibial artery


How many retinacula are there in the foot? What surrounds each tendon beneath the retinaculum?

5; tendon sheaths surround the tendons to prevent rubbing


Does the foot have intrinsic muscles on the dorsal side?



What are the intrinsic foot muscles on the dorsal side? Where do these muscles insert? What are they innervated by?

extensor hallicus brevis to the big toe
extensor digitorum brevis to other toes;
these muscles insert into the extensor hood;
deep fibular nerve


What does the deep fibular nerve supply in the foot?

Intrinsic foot muscles and a tiny area of cutaneous innervation between the big toe and the second digit. The rest of the foot is taken care of by the superficial fibular.


Why is it important to learn cutaneous innervation to the foot?

important for local anesthesia for foot surgeries


What does the anterior tibial artery become?

dorsalis pedis


How do you find the dorsalis pedis pulse?

Look for the extensor hallucis and tibialis anterior - it lies between these two tendons.


What artery gives off a dorsal arch and a perforating branch that hooks up with the lateral plantar artery to form the plantar arch?

dorsalis pedis


On the dorsal aspect of the foot, what does the deep fibular innervate after innervating the intrinsic foot muscles? What's the rest of the dorsal aspect of the foot innervated by?

small sensory innervation to an area between the big and second toe; superficial fibular (except the tips of toes)


How many layers of intrinsic foot muscles are there on the plantar side?



If you peel pack the palmar aponeurosis, how many muscles are found in the first layer? What are they?

abductor hallucis
abductor digiti minimi
flexor digitorum brevis


What are the muscles found in the second layer of the plantar foot? What is unique about the muscles found in this layer?

flexor accessorius
this layer's muscles are associated with the long tendons of the flexor digitorum longus (deep posterior compartment muscle)


What muscles are found in the third layer of the plantar foot?

flexor hallucis brevis
flexor digiti minimi brevis
adductor hallucis ** 2 heads (transverse and oblique)


What are the deepest muscles (4th layer) of the foot? What is different about these interossei from those of the hand?

7 interossei: 4 dorsal and 3 plantar; the only difference between these interossei is their relation to the functional "midline" -- in the foot, the second digit is considered the midline


The tibial nerve divides into the lateral and medial plantar nerves. Which nerve acts just like the ulnar nerve? What does it supply?

lateral plantar is just like the ulnar nerve; it supplies all intrinsic muscles of the foot except for the 2 muscles to the big toe (thenar equivalents), 1 lumbrical to the functional midline on the medial side, and the flexor digitorum brevis.
** innervates the flexor accessorius and the adductor hallucis


What nerve acts just like the median nerve in the foot? What does it innervate?

medial plantar nerve; innervates the thenar equivalents (2 muscles), 1 lumbrical to the function midline on the medial side, and the flexor digitorum brevis


How many cutaneous branches contribute to the plantar aspect of the foot?



Which nerve supplies cutaneous innervation to most of the heel on the sole of the foot? To the medial side? Lateral side?

tibial to the heel; saphenous medially; sural laterally


What nerve supplies cutaneous innervation to 1.5 toes on the lateral side?

lateral plantar nerve
**goes over the dorsal aspect of the foot to innervate the tips of the toes, as well


what nerve supplies cutaneous innervation to 3.5 toes on the medial side?

medial plantar nerve
**goes over the dorsal aspect of the foot to innervate the tips of the toes, as well


Which toe is the functional midline in the foot?

second digit


What are the "thenar equivalents" in the foot? What are the "hypothenar equivalents?" Which of the three muscles found in the hand is missing in these compartments of the foot?

hallucis muscles (big toes muscles); little toe muscles; no opponens!!


What are two plantar foot muscles that have no real equivalent in the hand?

flexor digitorum breivs
**sort of like the FDS in the forearm, its tendons split and allow the FDP tendon to pass through and attach to the distal phalanx
flexor accessorius


What does the flexor accessorius do?!

Tendons of the FDB start medially and head laterally to insert into the distal phalanges. If you dorsiflex the foot, this would pull the toes toward the medial side. So, the flexor accessorius acts to straighten out the pull on the toes when you flex.


This muscle attaches to the long tendons of the flexor digitorum brevis and to the calcaneus and causes a straight posterior pull of the toes upon dorsiflexion.

flexor accessorius **no equivalent in the hand