Manual 83-89: Muscles of Leg Flashcards
deep fascia of leg
crural fascia
attachements to crural fascia
- patella
- patellar ligament
- tibial tuberosity
- condyles of tibia
- head of fibula
the crural fascia receives fibers from tendons of ..
biceps femoris
SGT - sartorius, gracillis, semitendinosus
semimembranosus
describe the subcutaneous periosteum of tibia
- continuous with deep fascia anteriorly
- thicker proximally and thinner distally
what distally forms the retinacula of the ankle
subcutaneous periosteum of tibia
what muscles take partial origin from subcutaneous periosteum of tibia
- tibialis anterior
- extensor digitorum longus
the deep surface of the subcutaneous periosteum of tibia give rise to…
anteriro intermuscular septa and posterior intermuscular septa and deep transverse fascia
separates the peroneus longus and brevis from each other and from muscles of anterior and posterior crural compartments
anterior and posterior intermuscular septa
muscles of anterior crural compatment
- tibialis anterior
- extensor hallucis longus
- extensor hallucis capsularis
- extensor digitorum longus
- peroneus tertius
what m covers the anterior tibial vessels and deep peroneal n (as courses distally in leg)
TA
origin of TA
- lateral condyle tibia
- upper 2/3 lateral surface of tibia
- interosseous membrane
- deep crural fascia
insertion of TA
- medial cuneiform (medial plantar surface)
- base of 1st met (medial plantar surface)
innervation of TA
deep peroneal n
functions of TA
- inversion ankle
- dorsiflexion ankle
- supination (adduction, inverison, plantarflexion) intertarsal jts
distally the anterior tibial vessels and deep peroneal n lie between ______ and TA
EHL
origin EHL
- middle 2/3 anterior surface of fibula (medial to EDL origin)
- itnerosseous membrane (accessory origin)
insertion EHL
- base of distal phalanx 1st digit (crest)
- base of 1st met (additional slip_
innervation EHL
deep peroneal n
functions EHL
- extend 1st MTPJ
- dorsiflex ankle
- supination at intertarsal jt
origin extensor hallucis capsularis
- EHL tendon
insertion extensor hallucis capsularis
medial surface of capsule of 1st MPJ
function of extensor hallucis capsularis
- lifts capsule out of joint to prevent entrapment of capsule in joint on extension
lateral extreme of anterior crural compartment
extensor digitorum longus
origin EDL
- lateral condyle of fibula
- head of fibula
- upper 3/4 anterior surface of fibula
- interosseous membrane
- deep fascia
- anterior intermuscular septum (separating m from peroneus longus)
what separates the EDL from peroneus longus
anterior intermuscular septum
insertion of EDL
extensor expansions of digits 2-5
innervation of EDL
deep peroneal n
functions EDL
- extend MTPJ (4 lateral digits)
- dorsiflexion ankle
- eversion ankle
- pronation (abduction and eversion) (intertarsal joints)
the peroneus tertius is considered part of what m
extensor digitorum longus
origin peroneus tertius
- lower 1/3 anterior surface fibula
insertion peroneus tertius
- base of 5th met (passes with EDL tendon)
innervation peroneus tertius
deep peoneal n
function peroneus tertius
- dorsiflexion ankle
- eversion ankle
- pronation intertarsal joints
all anterior compartment m are innervated by …
deep peroneal n
muscles of lateral crural compartment
peroneus longus
peroneus brevis
most superficial m in lateral crural compartment
peroneus longus
where does the common peroneal n enter the anterior compartment
between attachments of peroneus longus to fibular head and body
origin of peroneus longus
- lateral condyle tibia
- head fibula
- upper 2/3, lateral surface fibula
- crural fascia
- both intermuscular septa
insertion of peroneus longus
- base of 1st met (lateral plantar side)
- medial cuneiform (lateral plantar side)
- base of 2nd met (occasional accessory insertion)
function peroneus longus
- plantar flexion ankle
- eversion ankle
- pronation intertarsal jt
describe the course of peroneus longus
- ends in long tendon and passes posterior to lateral malleolus with tendon of peroneus brevis
- goes deep to superior peoneal retinaculum and passes across calcaneus distal to peoneal trochlea and under the inferior peroneal retinaculum
- lateral then medial side of cuboid
- goes under long plantar ligament to its insertions
sesamoid bone located in tendon of peroneus longus near the cuboid
os peroneum
m found deep to peroneus longus
peroneus brevis
origin of the peroneus brevis
- lower 2/3, lateral surface of fibula
- crural fascia
- both intermuscular fascia
insertion of the peroneus brevis
- tuberosity of 5th met
innervation of peroneus brevis
superficial peroneal n
function peroneus brevis
- plantarflex ankle
- evert ankle
- pronate intertarsal jt
all lateral compartment m are innervated by ..
superficial peroneal n.
course of peroneus brevis
- tendon passes posterior to lateral malleolus
- anteriro to tendon of peroneus longus and inserts
variations in lateral crural compartment
- two m are sometimes fused
- slips from peroneus longus can go to.. base of 3-5th met and adductor hallucis
- peroneus accessories m originating from fibula, between longus and brevis with tendon joining longus
- peroneus digit minimi may be a separate m
how often is a peoneus quartus present
10-15%
- arises on fibula, b/w peoneus brevis and flexor hallucis longus
- inserts on peroneal trochlea of calcaneus or tuberosity of cuboid
superficial posterior crural m group
gastrocnemius
soleus
plantaris
medial head gastroc origin
- medial condyle femur (proximal and posterior part)
- posterior to adductor tubercle
lateral head gastroc origin
- lateral condyle femur (depression on lateral side)
insertion gastroc
- two heads approach midline at tendinous raphe
- aponeurosis tapers distally and joins soleus m to form tendocalcaneus
- tendocalcaneus inserts central part, posterior surface of calcaneus
innervation gastroc
tibial n
functions gastroc
- plantarflex ankle
- supination (adduction and inversion) (intertarsal jts)
- flex knee
gastroc and soleus =
triceps surae
origin soleus
- head and body, posterior surface of fibula
- soleal line, middle 1/3 tibia
- tendinosus arc b/w tibia and fibula
what passes under the tendinous arch between tibia and fibula
politeal vessels and tibial n
insertion soleus
tendocalcaneus, into calcaneus
innervation soleus
tibial n
functions soleus
plantarflex ankle
tendon found b/w gastroc and soleus
plantaris
- runs along MEDIAL border of tendocalcaneus
how often is plantaris absent
10%
origin plantaris
- lataeral supracondylar line (femur)
- oblique popliteal ligament
insertion plantaris
- medial side, posterior surface of calcaneus
- tendocalcaneus occasionally
innervation plantaris
tibial n
functions plantaris
- plantarflex ankle
- flex knee
separates superficial and deep posterior crural muscles
deep transverse fascia
deep group posterior muscles
popliteus
FHL
FDL
TP tibialis posterior
origin popliteus m
- groove on lateral condyle femur
- arcuate popliteal ligament
- lateral meniscus
insertion popliteus m
body of tibia, proximal to soleal line
innervation popliteus
tibial n
functions popliteus
- flex knee
- rotate knee
WB = rotates thigh laterally NWB = rotates leg medially
origin FHL
- distal 2/3 posterior surface fibula
- interosseous membrane
- posterior intermuscular septum
insertion FHL
base of distal phalanx, 1st digit
innervation FHL
tibial n
functions FHL
- flex (interphalangeal jt, 1st digit)
- plantarflex ankle
- supination at intertarsal jts
course of FHL
- tendon passes in groove, posterior surface distal tibia
- over posterior surface talus
- over inferior sruface of sustentaculum tali
- goes to sole of foot b/w two heads of FHB to its insertion
origin FDL
proximal 2/3 of body - posterior surface, medial to vertical lien, below soleal line on tibia
insertion FDL
bases, distal phalanges, digits 2-5
innervation FDL
tibial n
functions FDL
- flex DIP
- plantarflex ankle
- supination intertarsal jts
course of FDL
- tendon passes posterior to medial malleolus (with tendon of TP)
- passes superficial to deltoid lig
- superficial to FHL
- joined by quadratus platnae
- divides into 4 tendons going to its insertions
what m lies between FHL and FDL
tibialis posterior
origin of TP
- posterior surface interosseous membrane
- posterior surface, lateral to vertical line, below soleal line (tibia)
- proximal 2/3 medial surface fibula
insertion TP
- tuberosity of navicular *
- sustantaculum tali (medial, intermediate, lateral)
- three cuneiforms
- cuboid
- bases met 2-4
innervation TP
tibial n
function TP
- supination (intertarsal jts)
- plantarflex (ankle)
course of TP
- tendon in groove FDL to posterior medial malleolus
- deep to flexor retinaculum
- superficial to deltoid ligament
- deep plantar calcaneonavicular ligament
variations in posterior crural muscles
- may be accessory heads of soleus
- lateral head of gastroc may be absent
- lateral head of sesamoid may contain sesamoid bone
- popiteus may have accessory head arising from sesamoid bone of gastroc
- popliteus minor m may be present (attaches to femur and posterior ligament of knee joint)
- peroneotibialis m may lie deep to popliteus m (attaches to head of fibula and oblique line of tibia)
- FHL may have accessor attachments to FDL
- fibulocalcaneus internum m may be found with proximal attachment to fibular head and distal attachment to calcaneus
- may be a flexor accessories digitorum longus with origin from fib or tib and insertion into quadratus plantae or directly to long flexor tendon
how often is there a sesamoid bone in lateral head of gastroc
2-5%
fabella