Exam 4B Flashcards
cutaneous innervation of the leg
anterior surface
superolateral: lateral sural cutaneous nerve
inferolateral: superficial fibular (peroneal) nerve
medially: saphenous nerve
cutaneous innervation of the leg
posterior surface
superolateral: lateral sural cutaneous nerve
inferolateral: sural nerve
medially: saphenous nerve
superior extensor retinaculum
attaches to distal parts of anterior borders of tibia and fibula
inferior extensor retinaculum
Y-shaped: stem of “Y” is directed laterally and attaches to superior surface of calcaneus, upper limb of “Y” attaches to medial malleolus, lower limb of “Y” reaches medial border of foot, becomes continuous with deep fascia of sole of foot
flexor retinaculum
located on medial side of ankle; extends from medial malleolus to medial surface of calcaneus (runs posteriorly and inferiorly)
superior fibular retinaculum
extends from lateral malleolus to lateral surface of calcaneus (runs posteriorly and inferiorly)
inferior fibular retinaculum
attaches at both ends to lateral surface of calcaneus
muscles of the posterior compartment
superficial group
gastrocnemius
soleus
plantaris
muscles of the posterior compartment
deep group
flexor digitorum longus
flexor hallucis longus
tibialis posterior
popliteus
muscles of the posterior compartment
superficial and deep separated by transverse inter muscular septum; all supplied by tibial nerve
gastrocnemius origin
medial head: popliteal surface, above medial condyle
lateral head: lateral surface of lateral condyle and distal end of lateral supracondylar line
gastrocnemius insertion
both heads join a common tendon (together with soleus), calcaneal tendon (Achilles tendon), inserts into posterior surface of calcaneus
gastrocnemius innervation
tibial nerve
gastrocnemius action
plantar flexion of foot at ankle joint
assists with flexion of leg at knee joint
soleus origin
soleal line and medial border of tibia, posterior surfaces of head and shaft of fibula and tendinous arch between tibial and fibular attachments
soleus insertion
posterior surface of calcaneus via calcaneal tendon
soleus innervation
tibial nerve
soleus action
plantar flexion of foot at ankle joint
plantaris origin
lateral supracondylar line of femur, immediately above origin of lateral head of gastrocnemius
plantaris insertion
tendon passes inferiorly and medially between gastrocnemius and soleus, descends along medial border of calcaneal tendon, inserts into posterior surface of calcaneus (plantaris tendon may fuse with calcaneal tendon)
plantaris innervation
tibial nerve
plantaris action
assists with plantar flexion of foot at ankle joint and flexion of leg at knee joint
flexor digitorum longus
most medially located of deep posterior muscles
flexor digitorum longus origin
posterior surface of shaft of tibia, inferior to soleal line
flexor digitorum longus insertion
tendon passes posterior to medial malleolus, under flexor retinaculum; enters sole of foot and divides into 4 tendons for lateral 4 toes
tendons pass through openings in corresponding tendons of flexor digitorum brevis; insert into bases of distal phalanges of lateral 4 toes (similar to flexor digitorum profundus in hand)
flexor digitorum longus innervation
tibial nerve
flexor digitorum longus action
flexion of lateral 4 toes (distal, middle and proximal phalanges); plantar flexion of foot at ankle joint
flexor hallucis longus
most laterally located of deep posterior muscles
flexor hallucis longus origin
posterior surface of shaft of fibula
flexor hallucis longus insertion
tendon passes posterior to medial malleolus, under flexor retinaculum; it grooves posterior process of talus (divides it into medial and lateral tubercles) and inferior aspect of sustentaculum tali and runs anteriorly in sole of foot to insert into base of distal phalanx of great toe
tendons of flexor hallucis longus and flexor digitorum longus cross each other on medial side of sole of foot (FDL tendon passes superficial [inferior] to FHL tendon)
flexor hallucis longus innervation
tibial nerve
flexor hallucis longus action
flexion of big toe (distal and proximal phalanges)
plantar flexion of foot at ankle joint
tibialis posterior
most deeply placed muscle of deep posterior group
tibialis posterior origin
posterior surface of shaft of tibia (inferior to soleal line), posterior surface of shaft of fibula and interosseous membrane
tibialis posterior insertion
in lower leg its tendon passes anterior (deep) to flexor digitorum longus; passes posterior and directly in contact with medial malleolus, under flexor retinaculum; inserts into tuberosity of navicular, and via small tendinous slips it also inserts into cuboid, cuneiforms and bases of 2nd to 4th metatarsals
tibialis posterior innervation
tibial nerve
tibialis posterior action
plantar flexion of foot at ankle joint
inversion of foot at subtalar and transverse tarsal joints
popliteus origin
within capsule of knee joint, from lateral surface of lateral condyle of femur (a few fibers also originate from lateral meniscus of knee joint)
popliteus insertion
emerges from knee joint and passes inferiorly and medially; inserts into posterior surface of shaft of tibia, superior to soleal line
popliteus innervation
tibial nerve
popliteus action
medial rotation of tibia (if foot is off ground) or lateral rotation of femur (if foot is on ground)
this action occurs at beginning of flexion from a fully extended (“locked”) knee joint
referred to as “unlocking” knee joint
posterior tibial artery
terminal branch of popliteal artery
begins at lower border of popliteus muscle
runs inferiorly in deep part of posterior compartment of leg accompanied by posterior tibial veins and tibial nerve
passes posterior to medial malleolus, under flexor retinaculum; at this point it is only covered by skin and fasciae; its pulse can be palpated approximately halfway between heel and medial malleolus
terminates by dividing into medial and lateral plantar arteries, deep to flexor retinaculum
posterior tibial artery branches
fibular artery circumflex fibular artery muscular branches to posterior leg posterior medial malleolar medial calcaneal branch medial and lateral plantar arteries
fibular artery
originates from proximal part of posterior tibial artery and it is its largest branch
descends posterior to fibula, within flexor hallucis longus or between it and tibialis posterior
supplies muscles in posterior and lateral compartments of leg
ends distally giving off branches to arterial anastomosis around ankle (posterior lateral malleolar branch) and to heel (lateral calcaneal branches)
it also gives off a perforating branch that pierces lower part of interosseous membrane to enter anterior compartment of leg and anastomose with a branch of anterior tibial artery
circumflex fibular artery
passes around neck of fibula; participates in arterial anastomosis around knee joint (may originate from anterior tibial artery)
posterior medial malleolar branch
participates in arterial anastomosis around ankle
medial calcaneal branches
supply medial aspect of heel
tibial nerve
terminal branch of sciatic nerve in lower ⅓ of posterior thigh
descends through popliteal fossa and passes under tendinous arch of soleus
runs inferiorly in deep part of posterior compartment of leg accompanied by posterior tibial artery and veins
passes posterior to medial malleolus, under flexor retinaculum
terminates by dividing into medial and lateral plantar nerves under flexor retinaculum
tibial nerve branches
muscular branches to soleus, flexor digitorum longus, flexor hallucis longus and tibialis posterior
medial calcaneal branches: supply skin over medial and inferior aspects of heel
articular branch to ankle joint
medial and lateral plantar nerves (terminal branches)
muscles of the anterior compartment
tibialis anterior extensor digitorum longus extensor hallucis longus fibularis tertius deep fibular nerve
tibialis anterior
superficial and medially located in anterior compartment
tibialis anterior origin
lateral condyle of tibia, lateral surface of shaft of tibia and interosseous membrane
tibialis anterior insertion
tendon passes under extensor retinacula, inserts into medial cuneiform and base of 1st metatarsal
tibialis anterior innervation
deep fibular nerve
tibialis anterior action
dorsiflexion of foot at ankle joint
inversion of foot at subtalar and transverse tarsal joints
extensor digitorum longus
superficial and laterally located in anterior compartment
extensor digitorum longus origin
lateral condyle of tibia, medial surface of shaft of fibula and interosseous membrane
extensor digitorum longus insertion
tendon passes under extensor retinacula and divides into 4 tendons (for lateral 4 toes); each tendon divides into 3 slips; central slip inserts into base of middle phalanx; 2 lateral slips join and insert into base of distal phalanx (similar to extensor digitorum in hand)
extensor digitorum longus innervation
deep fibular nerve
extensor digitorum longus action
extension of lateral 4 toes (distal, middle and proximal phalanges), dorsiflexion of foot at ankle joint
extensor hallucis longus
its upper part is deeply located, covered by tibialis anterior and extensor digitorum longus muscles in lower leg it becomes superficial
extensor hallucis longus origin
medial surface of shaft of fibula and interosseous membrane
extensor hallucis longus insertion
tendon passes under extensor retinacula and inserts into base of distal phalanx of great toe
extensor hallucis longus innervation
deep fibular nerve
extensor hallucis longus action
extension of great toe (distal and proximal phalanges)
dorsiflexion of foot at ankle joint
fibularis tertius
it is essentially a lateral slip of extensor digitorum longus, from which it is rarely completely separated
fibularis tertius origin
medial surface of shaft of fibula and interosseous membrane
fibularis tertius insertion
tendon passes under extensor retinacula and inserts into dorsal aspects of shaft and base of 5th metatarsal
fibularis tertius innervation
deep fibular nerve
fibularis tertius action
dorsiflexion of foot at ankle joint
eversion of foot at subtalar and transverse tarsal joints
anterior tibial artery
terminal branch of popliteal artery
begins at lower border of popliteus muscle, passes forward, into anterior compartment of leg, through an opening in upper part of interosseous membrane
in upper ⅔ of leg is deeply located, descends on interosseous membrane covered by muscles of anterior compartment
in distal ⅓ of leg is superficial, passes anterior to distal end of tibia, covered only by skin and fasciae
at ankle, it is crossed anteriorly (from lateral to medial) by tendon of extensor hallucis longus
distal to ankle, it continues on dorsum of foot as dorsalis pedis artery
along its course, it is accompanied by anterior tibial veins and deep fibular nerve (nerve is lateral to artery)
anterior tibial artery branches
muscular branches: supply muscles of anterior and lateral compartments of leg
anterior tibial recurrent artery: participates in arterial anastomosis around knee joint
branches that participate in arterial anastomosis around ankle joint (anterior medial and anterior lateral malleolar arteries)
deep fibular nerve
terminal branch of common fibular nerve
begins deep to fibularis longus muscle, lateral to neck of fibula (in lateral compartment of leg)
pierces anterior intermuscular septum, which separates anterior and lateral compartments, and enters anterior compartment of leg
in anterior compartment, it descends with anterior tibial artery and veins (lateral to them)
continues onto dorsum of foot (does not change name like artery does)
deep fibular nerve branches
muscular branches: supply muscles of anterior compartment of leg
articular branch: ankle joint
muscles of the lateral compartment
fibularis longus
fibularis brevis
superficial fibular nerve
fibularis longus
superficial muscle of lateral compartment
fibularis longus origin
lateral surfaces of head and shaft of fibula
fibularis longus insertion
tendon passes posterior to lateral malleolus (under superior fibular retinaculum), runs anteriorly and inferiorly on lateral surface of calcaneus (under inferior fibular retinaculum), curves around cuboid and enters a groove on its inferior surface (groove is transformed into an osteofibrous tunnel by long plantar ligament), crosses sole of foot from lateral to medial, inserts into medial cuneiform and base of 1st metatarsal
fibularis longus innervation
superficial fibular nerve
fibularis longus action
plantar flexion of foot at ankle joint
eversion of foot at subtalar and transverse tarsal joints
fibularis brevis
lies deep to fibularis longus muscle
fibularis brevis origin
lateral surface of shaft of fibula
fibularis brevis insertion
tendon passes posterior and directly in contact with lateral malleolus (under superior fibular retinaculum), runs anteriorly and inferiorly on lateral surface of calcaneus (under inferior fibular retinaculum), inserts into tuberosity (styloid process) of base of 5th metatarsal
fibularis brevis innervation
superficial fibular nerve
fibularis brevis action
plantar flexion of foot at ankle joint
eversion of foot at subtalar and transverse tarsal joints
avulsion fracture of the tuberosity of the 5th metatarsal
when foot is suddenly and forcibly inverted, tuberosity of 5th metatarsal may be avulsed (torn away) by tendon of fibularis brevis
common in basketball and tennis players
associated with severely sprained ankle
causes pain, edema and bruising at base of 5th metatarsal
blood supply of the lateral compartment
no major artery passes vertically through lateral compartment of leg
main sources of blood supply: anterior tibial and fibular arteries
branches of anterior tibial artery perforate anterior intermuscular septum to supply lateral compartment
branches of fibular artery perforate posterior intermuscular septum to supply lateral compartment
superficial fibular nerve
terminal branch of common fibular nerve
begins deep to fibularis longus muscle, lateral to neck of fibula (in lateral compartment of leg)
lies at first deep to fibularis longus and then descends between fibularis longus and brevis and extensor digitorum longus
in lower leg pierces deep fascia and becomes superficial
superficial fibular nerve branches
muscular branches: supply fibularis longus and fibularis brevis muscles
medial and intermediate dorsal cutaneous nerves: supply skin of inferolateral part of anterior leg, dorsum of foot and dorsal surfaces of toes, except adjacent sides of great and 2nd toes (supplied by deep fibular nerve) and lateral side of little toe (supplied by lateral dorsal cutaneous nerve, continuation of sural nerve)
structures that pass anterior to the ankle, superficial to the inferior extensor retinaculum
saphenous nerve
great saphenous vein
branches of superficial fibular nerve
structures that pass anterior to the ankle, deep or through the inferior extensor retinaculum
tendon of tibialis anterior tendon of extensor hallucis longus tendons of extensor digitorum longus tendon of fibularis tertius anterior tibial artery and veins deep fibular nerve
structures that pass posterior to the medial malleolus, deep to the flexor retinaculum AM - PL
tendon of Tibialis posterior tendon of flexor Digitorum longus posterior tibial Artery and veins tibial Nerve tendon of flexor Hallucis longus Tom Dick And Nervous Harry
structures that pass posterior to the lateral malleolus, superficial to the superior fibular retinaculum
sural nerve
small saphenous vein
structures that pass posterior to the lateral malleolus, deep to the superior fibular retinaculum
tendon of fibularis brevis
tendon of fibularis longus
