L: Anterior, Lateral Leg, and Dorsum of the Foot
blood supply of lateral compartment of leg?
- perforating branches from anterior tibial and peroneal (fibular) aa. - *does not have its own artery* TEST Q!
name the muscles of the lateral compartment of the leg
- peroneus (fibularis) longus m. - peroneus (fibularis) brevis m.
general function, innervation, and blood supply of lateral leg compartment?
- plantarflexion, eversion - superficial peroneal (fibular) n. (L5-S2) - fibular a. & anterior tibial a. -- however NO DIRECT BLOOD SUPPLY
action of extensor digitorum brevis
extension of toes 2-4
adductor canal?
femoral a., femoral v., saphenous n.
action of extensor hallucis longus m.
great toe extension and ankle dorsiflexion
what innervates the extensor digitorum brevis and extensor hallucis brevis?
*deep fibular n.*
shin splints?
- commonly used to describe leg pain - causes: typically an overuse injury, strain of tibialis anterior m. AND/OR tibialis posterior m., tears/inflammation of tibial periosteum - may lead to stress fracture if not treated properly
superficial veins of the leg?
- dorsal venous arch (flip flop!) - great saphenous v. (anterior to medial malleolus) - small saphenous v. (posterior to lateral malleolus) great saphenous vein runs anterior to medial malleolus, runs up the medial shin (tibia) then dives posterior at knee, continues up medial thigh and dives into the femoral vein. the small saphenous goes posterior to lateral malleolus (part of fibula) then courses midline up posterior leg. dives into crural fascia of popliteal fossa into popliteal vein. saphenous nerve = terminal branch of femoral nerve!! runs with the great saphenous for sensory info on medial knee/leg. runs with femoral a., femoral v. in adductor canal. the sural nerve runs with the small saphenous
general function, innervation, and blood supply of anterior leg compartment?
- dorsiflexion (toes go up!) - deep peroneal (fibular) n. (L4-S2) - anterior tibial a. DAD
name the 2 muscles on the dorsum of the foot
- extensor digitorum brevis - extensor hallucis brevis
compartment syndrome?
- increased pressure in the compartment can lead to m. and n. damage and restrict blood flow - acute and chronic forms - may see decreased sensation over the dorsal web space between the 1st and 2nd digit - 4 compartment fasciotomy video! If you have trauma or inability to decrease fluid build up or crush-type injury bleeding a lot those boundaries aren't going to expand, get neurovascular compromise, vessels get compressed. Cell death! Symptoms going distally. Very traumatic. Can be chronic with leg swelling with walking or acute from trauma. Fasciotomy is cutting fascia open. Fluids just gush out. You release the pressure in the leg that can restore blood supply and take pressure off nerves that are there. Leave open a few days and then close up! Very interesting.
general function, innervation, and blood supply of posterior leg compartment?
- superficial group: plantarflexion - deep group: plantarflexion, inversion - tibial n. (L4-S3) - posterior tibial a. & fibular a.
name the 4 muscles of the anterior compartment of the leg
1. tibialis anterior m. 2. extensor digitorum longus m. 3. extensor hallucis longus m. 4. peroneus (fibularis) tertius m. think about extending toes to ceiling you see these extensors!
what are the main nerves of the anterior and lateral leg?
Both peroneus longus and brevis evert and plantar flex. Talking about nerve courses. All of this innervation/motor supply comes from sciatic nerve. Comes down and splits into tibial nerve and common fibular nerve which courses around the fibular head. Hit lateral leg by knee hard enough get pain down leg because mechanically stimulated common fibular nerve. Be careful. Courses anteriorly to deep fibular nerve. Shows motor branches to muscles it innervates.
bones of the foot
Generally she's naming general bone but there are bony features/extra parts we need to know. All info we need to know is in the structure list. Most of our tendons attach on the foot. Muscles are there to move the ankle. Calcaneus is posterior inferior bone. Heel strike. Heel bone = calcaneus. Sitting on top is the talus. Cool dynamic bone. No muscular attachment on it!!! Has ligaments though to stabilize the ankle. On top of talus is articular/hyaline cartilage. Part of ankle articulation. Superior view over foot. Big toe medial. Pinky toe lateral. Navicular. Medial, intermedial, lateral cuneiforms. Medial intermediate lateral or first second third. On lateral side have large cube-like bone called cuboid just anterior to calcaneus. Articulates with 4th and 5th metatarsals and phalanges. With each phalange we have 3 bones. Prox middle distal phalanx (single term). In toes 2-5 have all 3. in first toe only proximal and distal.
cutaneous nerves of the leg?
Highlight ones to know/be careful of. Saphenous nerve. Superficial fibular nerve exits out of lateral leg as it innervates one of the compartments we talk about. Continues onto top of foot as sensory innervation. Touch top of foot. Feel socks. Part of information comes from superficial fibular nerve. What's really cool is another nerve. Sensory innervation between 1st and 2nd dorsal web space of the foot. Little blue wedge is innervation from the deep fibular nerve. Deep fibular nerve responsible for innervating all muscles in anterior compartment of leg. Trauma in muscles you have massive hemmhorage. Massive neurovascular damage. Test how healthy the compartment is. Take little finger and rub that dorsal web space and if you have altered/no sensation she can say that a clinical sign is there's compromise in that compartment. So serious that may need immediate surgery. Could dictate course of treatment! Quick easy way to test integrity of leg that is vulnerable to high velocity trauma. Sural nerve!
action of extensor digitorum longus m.
extends digits 2-5, ankle dorsiflexion, weak eversion
O and I peroneus (fibularis) brevis m.
O: distal 2/3 of lateral fibula I: base of 5th metatarsal
O and I fibularis tertius m.
O: distal fibula I: base of 5th metatarsal aka peroneous tertius. looks like muscle belly blends with the extensor digitorum longus. 10% of people don't even have this, not very strong.
O and I of extensor hallucis longus m.
O: medial fibula and IM I: base of distal phalanx of great toe (dorsal surface)
O and I extensor digitorum longus m.
O: proximal 1/2 of fibula, lateral tibial condyle I: distal and middle phalanges of digits 2-5
O and I peroneus (fibularis) longus m.
O: proximal, lateral fibula I: plantar surface of base of 1st metatarsal and medial cuneiform head of fibula down entire length, tendon is enormously long, one of her favorites to show us in lab! courses around lateral malleolus and goes underneath the foot! crazy long!
O and I tibialis anterior m.
O: proximal, lateral tibia and IM (=interosseous membrane) I: medial cuneiform, base of 1st metatarsal it crosses the anterior ankle joint. biggest, fattest tendon at ankle on medial side. crosses down with solid attachment!
O and I extensor hallucis brevis
O: superolateral surface of calcaneus I: proximal phalanx of great toe
O and I extensor digitorum brevis
O: superolateral surface of calcaneus I: tendons of the EDL and extensor hoods
retinacula of foot
Think retinacula. Noncontractile tissue that holds things down. Seatbelt. Think of these the same way. If we didn't have this retinacula, you'd have tendons instead of following course of leg they'd go straight and bowstring out. Nicely fitted. You'll cut through this it's pretty rigorous. Extensor retinacula because extends toes. KNOW it kind of makes a Z. extensor retinacula makes a Z pattern you'll see in dissection. Other retinacula = peroneal. Courses around peroneus longus/brevis. 2 distinct bands. Superior band and inferior band. Inferior more on the foot and superior more behind lateral malleolus. Superior band has clinical relevance and you can rupture that. Surgery not always successful. Peroneal tendons pop out. Pouch lining tunnels to decrease friction. Synovial fluid. Feels like eggwhite. We might feel synovial fluid.
bones of the leg
Tibia and fibula. Tibia medial side. Kicked in shin. Shinbone. Tibia. If you touch tibia and get kicked, you're touching thin layer of skin that goes right to bone no muscle. Fibula is lateral doesn't bear much weight. As a strut and connecting point for muscle attachment. Lots of muscles coming off it. Feel fibular head up towards knee. Feel lateral malleolus distally. Bears about 10% body weight when weight bearing, no huge biomechanical effect. Critical for muscle attachment. Superior aspect. Proximal tibia. On top portion we call the top part tibial plateaus because really flat. Technically the whole lateral/medial side are really called tibial condyles. They don't look like the condyles of the femur. In the middle is the "mountain range" between 2 plateaus = intercondylar eminence or tibial spine. Use that interchangably. Where distal components of ACL and PCL attach. Between these 2 bones is the interosseous membrane. IM = interosseous membrane. On tibial you also have medial malleolus. On posterior view not much exciting but know the soleal line. Can make out raised ridge of bone. Where soleus attaches. Muscle attachment.
action of tibialis anterior m.
ankle dorsiflexion, inversion helps to support the medial arch of the foot
action of lateral compartment of leg muscles?
ankle eversion, weak plantarflexion
what is the vasculature of the anterior leg?
anterior tibial a. - branches from popliteal a. - enters anterior compartment through interosseous membrane changes name to *dorsalis pedis a.* after crossing ankle Popliteal artery continues down and it splits again. Just below popliteal fossa splits into anterior tibial artery goes through hole in IM. Once artery pops through anterior side it runs down the IM. mid portion anterior leg it meets up with deep fibular nerve. When anterior tibial artery crosses ankle turns into dorsalis pedis. Dorsopedal pulse.
blood supply to anterior compartment of thigh?
anterior tibial artery and vein
what does the sciatic nerve split to?
common peroneal (fibular) and tibial nerves. the fibular courses around fibular head and splits again into deep and superficial fibular nerves.
what innervates the anterior compartment of the leg?
deep peroneal (fibular) n. (L4-S2)
where is a common site for avulsion fracture?
distal attachment of peroneus brevis (roll ankle hard) -- tendon pulled so hard it pulled bone with tendon attached!
action of fibularis tertius m.
dorsiflexion and eversion
action of peroneus (fibularis) brevis m.
eversion, weak plantarflexion
action of peroneus (fibularis) longus m.
eversion, weak plantarflexion helps support the medial arch
action extensor hallucis brevis
extend metatarsophalangeal joint of great toe
innervation of lateral compartment of leg?
superficial peroneal (fibular) n. (L5-S2)
