LEA Anterior Compartment of the Leg Flashcards
the anterior compartment is enclosed by
dense fascia, bone, interosseous membrane
the anterior compartment is susceptible to
compartment syndrome
anterior compartment get blood supply from
anterior tibial artery
muscles of anterior compartment innervated by
deep fibular nerve
deep fibular nerve roots
L4,5,S1
tendons are surrounded by _ as they pass ankle
synovial sheath
tendons are visible and palpable with
contraction
function of anterior compartment muscles
ankle dorsiflexion and extend digits
tibialis anteiror tendon is palpable and visible __
as it crosses the ankle joint and proximally
the largest anterior muscle
tibialis anterior
origin of tibialis anterior
lateral tibial condyle, upper 2/3 lateral surface of tibial shaft, interosseous membrane, crural fascia
insertion of tibialis anterior
medial plantar surfaces of medial cuneiform, medial plantar surfaces of 1st met base (metatarsal tubercle)
function of tibialis anterior
dorsiflex and invert footsupinate subtalar joint
Extensor digitorum longus origin
lateral tibial condyle, superior 3/4 of fibular shaft, interosseous membrane, crural fascia
insertion of extensor digitorum longus
tendons divide into 4 slips (digits 2-5) that insert on the dorsal surface of the bases of 2nd-5th middle and distal phalanges
contributes to extensor expansion over digits (2-5)
extenders digitorum longus
function of extenders digitorum longus
-digit (proximal and distal interphalangeal joints, metatarsophalangeal joints) extension (dorsiflexion)-helps with dorsiflexion/eversion (subtalar pronation)
Extensor hallucis longus is deep to
TA and EDL,
Extensor hallucis longus becomes superficial
distal leg/ankle
Extensor hallucis longus tendon is between __ at the ankle joint
TA and EDL
origin of Extensor hallucis longus
middle ½ of the -anteromedial aspect of middle fibular shaft and interosseous membrane- more distal than TA and EDL
insertion of Extensor hallucis longus
dorsal aspect of base of distal phalanx of 1st digit
function of Extensor hallucis longus
extend (dorsiflex) 1st digit (hallux)
Extensor hallucis capsularis origin
medial aspect of EHL tendon or muscle (sometimes TA)
insertion of extensor hallucis capularis
Dorsomedial aspect of 1st MPJ capsule
function of extensor hallucis capularis
tension capsules during extension preventing capsular impingement
Fibularis (peroneus) tertius
sometimes absent
origin of Fibularis (peroneus) tertius
inferior ¼ of medial fibular shaft, interosseous membrane (Can also originate from the EDL muscle)
insertion of Fibularis (peroneus) tertius
dorsal aspect of base and shaft of 5th metatarsal (Sometimes the base of the 4th metatarsal)
function of Fibularis (peroneus) tertius
foot dorsiflexion and eversion, subtalar pronation*passes anterior to lateral malleolus
tibialis anterior begins __
proximal to superior extensor retinaculum (transverse crural ligament)
tibialis anterior ends __
between oblique bands of inferior extensor retinaculum (cruciate crural ligament)
tibialis anterior is within
the superior extensor retinaculum and oblique superomedial band of inferior extensor retinaculum
tibalis anterior begins and ends
most proximally
extensor hallucis longus begins
immediately proximal to oblique superomedial band of inf ext retinaculum (level of medial malleolus)
extensor hallucis longus ends
at the 1st metatarsal base
extensor hallucis longus with within
the inferior extensor retinaculum
extensor hallucis longus ends most
distally
Extensor Digitorum Longus and Fibularis Tertius share
a synovial sheath ( 4 tendons of EDL and 1 of FT)
Extensor Digitorum Longus and Fibularis Tertius begins
just proximal to oblique superomedial band of inf ext retinaculum
Extensor Digitorum Longus and Fibularis Tertius ends
ends at level of 5th metatarsal base
Extensor Digitorum Longus and Fibularis Tertius within the
inferior extensor retinaculum
Hold extensor tendons in place over the extensor surface of ankle joint
extensor retinacula
Superior Extensor Retinaculum(Transverse Crural Ligament) is
a thickening of crural fascia (fascia cruris)
Superior Extensor Retinaculum(Transverse Crural Ligament) attaches
anterior aspect of the tibial and fibula distal shafts
__ within the retinaculum, the rest pass deep
tibialis anterior
Inferior Extensor Retinaculum(Cruciate Crural Ligament)
Thickening of crural fascia and deep fascia over foot dorsum
Y shaped band with a stem and 2 oblique medial bands
Inferior Extensor Retinaculum(Cruciate Crural Ligament)
Stem of the Y is lateral and called the
frondiform ligament
Lateral attachment (frondiform ligament):
lateral talar neck, superior calcaneus within the sinus tarsi
Medial attachment of frondiform ligament:
anterior/distal medial malleolus (oblique superomedial band), plantar medial cuneiform/navicular (oblique inferomedial band)
the inferior extensor retinaculum is continuous with
inferior fibular retinaculum
Tendons of anterior compartment muscles pass within
the inferior extensor retinaculum
Anterior tibial artery is a terminal branch from
popliteal
Anterior Tibial artery Passes through
proximal opening in the interosseous membrane to enter anterior compartment
Anterior tibial is located between __proximal leg
TA and ED muscles
Anterior tibial is Located between __ in the distal leg
TA and EHL
EHL tendon crosses over artery in
Distal ankle
anterior tibial becomes dorsalis pedis `
after ankle
Dorsalis pedis is located between
EDL and EHL
A small anterior tibial artery can be replaced by
perforating branches from posterior tibial and the perforating or fibular artery
anterior tibial branches off popliteal artery near
inferior border of popliteus
anterior tibial artery passes through __ to enter anterior compartment
superior opening of interosseous membrane
Branches of anterior tibial
-Posterior tibial recurrent -Anterior tibial recurrent-Muscular branches-Anterior medial malleolar artery-Anterior lateral malleolar artery-Dorsalis pedis (continuation of anterior tibial)
anterior and posterior tibial veins drain into __
popliteal
popliteal drains into __ after receiving anterior and posterior tibial
femoral vein
Deep fibular nerve root levels
(L4-S1)
Deep fibular nerve branches from
common fibular
deep fibular nerve enters anterior compartment by
passing through anterior intermuscular septum
Descends along anterior surface of the interosseous membrane (with anterior tibial artery)
deep fibular nerve
deep fibular nerve is _ to artery in leg and ankle
lateral
deep fibular nerve supplies
anterior compartment and foot dorsum muscles
deep fibular nerve enters dorsum of foot by
Passing deep to extensor retinacula
branches of deep fibular nerve
lateral terminal branch and medial terminal branch
lateral terminal branch
follows the lateral tarsal or arcuate arteries
which branch is a continuation of deep fibular nerve
Medial terminal branch
Lateral terminal branch of deep fibular nerve innervates
EHB and EDB, joints of lateral foot
Medial terminal branch of deep fibular nerve communicates with
superficial fibular nerve (communicating branch of superficial fibular nerve
Follows dorsalis pedis and 1st dorsal metatarsal arteries
medial terminal branch of deep fibular nerve
medial terminal branch of deep fibular nerve innervates
1st dorsal interossei muscle, joints of medial foot
Branches of medial terminal branch:
Proper dorsal digital nerve 2and Proper dorsal digital nerve 3
Cutaneous innervation of dorsomedial 2nd toe
Proper dorsal digital nerve 3
Cutaneous innervation of dorsolateral hallux
Proper dorsal digital nerve 2
Injury to Deep fibular:
-Footdrop (increased tripping with gait)-Weak/loss of toe extension, ankle dorsiflexion-Steppage gait-Altered sensation 1st web space
Altered sensation 1st web space with damage to deep fibular nerve effects
-Dorsolateral side of hallux-Dorsomedial side of 2nd digit
Toe tips are innervated by
nerves from the plantar aspect of the foot