Leg Flashcards
muscles that compose dynamic support of longitudinal arch
Tibialis posterior Tibialis anterior Flexor hallucis longus Fibula's longus Intrinsic plantar muscles
muscles that compose passive support of longitudinal arch
plantar aponeurosis
long plantar ligament
short plantar ligament
plantar calcaneonavicular/spring ligament
posterior compartment of the leg (general)
flexors, calf
transverse septa divides it into two groups:
1. superficial posterior
2. deep posterior
tibial nerve and tibial vessels are deep to transverse crural intermuscular septum
muscles of the superficial posterior group (3)
gastrocnemius
soleus (triceps surae)
plantaris
muscles of the deep posterior group (4)
popliteus
flexor hallucis longus
flexor digitorum longus
tibialis posterior
Gastrocnemius heads
most superficial of the superficial posteriors
crosses knee and ankle joints
Medial and Lateral head
medial is larger, starts above medial femoral condyle (lateral is above lateral condyle)
both insert and compose achilles tendon
actions of gastrocnemius
plantar flexion and flexes leg at knee joint
flexes the knee below the knee
fabella
some patients have it, seismoid bone found close to proximal attachment
potentially provides leverage for lateral head of gastrocnemius
if fractured, it may accompany total knee replacement
a rare cause of posterolateral knee pain
soleus (general)
posterior, superficial group
broad, flat, mutlipennate muscle
horseshoe shaped origin (soleal line of tibia, head of fibula)
inserts into achilles tendon
where is the achilles tendon? what muscle tendons compose it?
it is located on the posterior surface of calcaneus
composed of muscles that attach to the tendon calcaneus
soleus, gastrocnemius (lateral and medial heads), plantaris (if present)
triceps surae
tripartite muscle that is formed between the two heads of the gastrocnemius and the soleus
forms the calf prominence
action of the soleus
plantar flexion
plantaris (general)
superficial posterior
small muscle, often absent (short belly and long tendon)
attaches to the lateral supracondylar line, runs between gastrocnemius and souls, attaches to the achilles tendon
function of plantaris
weak plantarflexion and leg flexion
possibly proprioceptive organ for foot position due to high density of proprioceptive receptors
clinical application of plantaris
used commonly in reconstructive hand tendon surgery due to little affect on knee/ankle movements
often ruptures during violent ankle movements (sudden dorsiflexion of ankle) common in basketball players, sprinters, and ballet dancers
popliteus (general)
deep posterior group
thin flat triangular muscle, deep to plantaris
forms inferior floor of popliteal fossa
inserts on lateral side of leg, origins on tibia
functions of popliteus
unlocks extended leg by laterally rotating femur on stationary tibia
flexes leg weakly
arteries of the popliteal fossa
superior medial and superior lateral genicular arteries (superior to medial and lateral heads of gastrocnemius)
inferior medial genicular artery (deep to medial gastrocnemius)
inferior lateral genicular artery (deep to plantaris, superficial to popliteus)
flexor hallucis longus (general)
largest deep posterior
lies deep to soleus
attaches to inferior fibula and passes inferiorly to deep flexor retinaculum
occupies shallow groove on posterior surface of sustentaculum tali of calcaneus
crosses deep to FDL tendon in sole of foot, approaches great toes between sesamoid bones in FHB tendons
inserts at base of distal phalanx of great toe
actions of flexor hallucis longus
flexes great toe
plantar flex foot at ankle joint
flexor digitorum longus (general)
deep to soleus and posterior to tibia
attaches to tibia and passes posterior to tibias posterior
diagonally in sole of food, superficial to f.h.l.
attaches at base of lateral four digits
functions of flexor digitorum longus
flexes lateral four digits
plantar flexes foot at ankle joint
tibialis posterior (general)
deepest posterior crural muscle
lies between F.D.L. and F.H.L.
attaches at the interosseous membrane, and both tibia and fibula
passes anterior to FDL
distally attaches to various tarsal and metatarsal bones
functions of tibialis posterior
inversion
plantar flexion
tibial nerve supplies which muscles of posterior compartment?
soleus gastrocnemius plantaris F.H.L. F. D.L. popliteus tibialis posterior
ALL OF THEM
tibial nerve pathway through the leg
passes with posterior tibial vessels
deep to soleus
posterior to tibialis posterior
leaves posterior by passing deep to flexor retinaculum between medial malleolus and calcaneous
divides into medial and lateral plantar nerves
blood supply of posterior compartment
posterior tibial artery
pathway of posterior tibial artery
begins near inferior popliteus (deep to soleus)
gives rise to fibular artery
passes inferomedially on posterior surface of tibias posterior with tibial nerve
runs deep to flexor retinaculum
ends by dividing into medial and lateral plantar arteries
fibular artery
descends from distal popliteus obliquely toward fibula
vascularizes posterior and lateral compartments
largest branch of posterior tibial artery
fibular artery
posterior tibial pulse
palpated between posterior surface of medial malleolus and medial calcanea tendon
pt. must relax foot via inversion because it is deep to flexor retinaculum
used to examine patients with occlusive peripheral arterial disease (intermittent claudication) caused by ischemia of leg muscles due to narrowing/occulsion of leg arteries
characterized by leg cramps and pain during wlaking
dural fascia
deep fascia of leg (continuous with fascia late)
covers leg muscles
part of proximal attachment of underlying muscles
thickens distally to form extensor retinaculum
prevents bowstringing during dorsifelxion
what divides the leg into its compartments
thick septa (anterior, lateral, and posterior) and the interosseous membrane
what do all the muscles within a compartment share?
same general function
nerve
artery and vein
anterior thigh muscle compartment general function and innervation
extension
femoral nerve
medial thigh muscle compartment general function and innervation
adduction
obturator nerve
posterior thigh muscle compartment general function and innervation
flexion
sciatic nerve
anterior compartment muscles
function in dorsiflexion and extension located anterior to the interosseous membrane
tibialis anterior
extensor hallucis longus
extensor digitorium longus
fibularis tertius
primary function: dorsiflexion, toe extension
tibialis anterior
long thick muscle on anterolateral surface of tibia
attaches to lateral condyle and distally on medial surface of cuneiform
function of tibialis anterior
dorsiflexion and inversion of foot
extensor digitorium function
extends lateral four digits
dorsiflexion
extensor expansion
distal attachment of the four tendons of the extensor digitorium
tendons insert over the lateral four proximal phalanges that divide into two lateral slips and one central slip (middle phalanx)
fibularis tertius
fuses with digitorium longus proximally but tendon doesn’t attach with digit
attachments: anteroinferior surface and dorsal of fifth metatarsal base
functions in dorsi flexion and eversion
extensor hallucis longus
lateral to tibialis anterior
attaches proximally to anteromedial fibular surface and distally at phalanx of hallux (big toe)
functions to extend hallux, dorsiflexion
deep fibular nerve
innervates anterior compartment
begins between fibula and fibulas longus muscles
runs inferomedially with anterior tibial vessels and ends in medial and lateral terminal branches on dorsal of foot
what does the deep fibular nerve supply
anterior compartment muscles
ankle joint and metacarpal phalangeal joints
dorsal intrinsic foot muscles
skin between first and second digits
anterior tibial artery
arises from popliteal artery
begins near inferior border of popliteus muscle passes anteriorly over the interosseous membrane
descends between EHL and TA muscles with deep fibular nerve
ends at malleoli to become pedis artery
lateral compartment of leg
found between anterior and posterior crural septa
contains:
fibularis brevis
superficial fibular nerve
fibularis longus
fibularis longus
lateral compartment
extends from fibular head to sole of foot
superficial to fibularis brevis
attaches to fibula, passes inferior and runs across sole of foot to attach at first metatarsal
functions: eversion and plantar flexion
fibularis brevis
deep to fibularis longus
attaches to lateral tibia, moves laterally to fifth metatarsal
functions in eversion and plantar flexion
superficial fibular nerve
one of terminal branches of common fibular
begins b/t fibularis longus and fibula
descends between fibular muscle and lateral to e.d.l.
what does the superficial fibular nerve supply
anterior inferior leg
entire dorsal surface of foot
most dorsal aspect of digits
superficial fibular nerve injury
most common injury of lower extremity nerves
results in paralysis of all anterior and lateral crural muscles
loss of dorsiflexion and eversion– foot drop
(high stepping gait, waddling, or swing out – can cause clop)
arterial supply of lateral compartment
fibular artery
largest branch of posterior tibial artery
compartment syndrome
injury to crural fascia septa
trauma that leads to hemorrhage, edema, and inflammation
intracompartmental pressure may lead to ischemia and permanent injury
perform fasciotomy to relive this pressure
shin splints
caused by repetitive micro trauma to tibialis anterior
causes small tears to periosteum of tibia
mild form of compartment syndrome
