Posterior Leg Flashcards
Division Ant/Post
tibia (medial)
interosseous membrane
fibula
posterior intermuscular septum (lat/post)
transverse intermuscular septum
divides superficial and deep compartments of posterior leg
superficial muscles
- gastrocnemius (medial + lateral heads)
- soleus
- plantaris
ankle plantarflexion
deep muscles
- popliteus
- flexor digitorum longus
- tibialis posterior
- flexor hallucis longus
toe flexion + weak plantarflex
motor innervation
all tibial baby L4-S3
-branches into medial + lateral plantar N
superficial muscle insertion
all 3 insert on calcaneal tuberosity
-gastrocnemius + soleus = calcaneal/achilles tendon
-plantaris = own tendon, not blended w/achilles
triceps surae
2 heads of gastrocnemius + soleus
95% of plantarflex strength
fibers twist for shock absorption + efficient propulsion
diabetic tendinopathy
degenerative process from glycation end product (from high BP) acc in load bearing collagenous structures aka tendons
abnormal collagen/matrix = dec vascular integrity so poor healing
gastrocnemius
o/i/v
medial head: og @ medial femoral condyle + popliteal surface
lateral head: og @ lateral femoral condyle + lateral margin
in @ calcaneal tuberosity
posterior tibial A (main) + popliteal A (proximal)
gastrocnemius
function
main ankle plantarflex when knee extended + ankle dorsiflex
-assist knee flexion (since crosses joint)
if knee if flexed then not plantarflex AT ALL
sprinting/jumping since high levels fast twitch fibers
soleus
o/i/v
arched og @ soleal line + medial tibia + posterior head fibula + proximal fibular shaft
in @ calcaneal tuberosity
posterior tibial A (main) + popliteal A (proximal) + fibular A (lateral)
soleus
function
ankle plantarflexion
if knee flexed = SOLE/only plantarflexor
standing/walking bc high levels slow twitch fibers
stroll with soleus
tendinous arch soleus
gap in proximal attachement of soleus (closer to knee/popliteal region)
tibial N + popliteal A enter the post compartment
-popliteal A splits into posterior + anterior tibial after enters arch
plantaris
og @ inferior end of lateral supracondylar line + oblique popliteal ligament
in @ calcaneal tuberosity
popliteal A only since right behind knee
scrawny thing
plantaris
function
proprioception bc high number of muscle spindles
popliteus
o/i/v
og @ lateral femoral condyle + lateral meniscus
in @ posterior surface tibia above soleal line
genicular A
popliteus
function
unlock knee when full extension/foot is planted by rotate femur laterally (full knee extension rotates femur lateral=lock)
if knee full extension/foot NOT planted then rotate tibia medially
flexor digitorum longus
o/i/v
og @ medial posterior surface tibia below soleal line
in @ base of digits 2-5/distal phalanges
posterior tibial A
most medial deep muscle, starts medial ends lateral
flexor digitorum longus
function
weak plantarflex
passive support of longitudinal foot arch
tibialis posterior
o/i/v
og @ posterior tibia below soleal line + interosseous membrane + posterior surface fibula
in @ tuberosity of navicular (main) + all 3 cuneiforms + cuboid + base of MT 2-4
posterior tibial A
tibialis posterior
function
inverts foot + weak plantarflexion
anterior also does inversion but dorsiflex instead of plantar
flexor hallicus longus
o/i/v
og @ inferior 2/3 posterior fibula + inferior interosseous membrane (lateral)
in @ base of distal phalanx digit 1 (medial)
fibular A
most lateral deep muscle, starts lateral ends medial
flexor hallicus longus
function
flex digit 1 at all joints
+ weak plantarflexion
+ passive support longitudinal foot arch
crosses FDL tendons at the foot
DTH
down to hug
medial > lateral @ posterior leg
flexor DIGITORUM longus
TIBIALIS posterior
flexor HALLUCIS longus
TDH
Tom, Dick, And Very Nervous Harry
anterior > posterior @ medial ankle
TIBIALIS posterior
flexor DIGITORUM longus
posterior tibial ARTERY + VEIN
tibial NERVE
flexor HALLUCIS longus
branches of popliteal A
- genicular A- 5 of them (popliteus)
- anterior tibial A
- posterior tibial A > fibular A
branches of posterior tibial A
- circumflex fibular A (but usually off of anterior)
- fibular A
- posterior medial malleolar A
- posterior medial calcaneal A
- medial + lateral plantar A (terminates, to supply sole foot)
branches fibular A
- communicating branch (anastomose fibular A + posterior tibial)
- posterior lateral malleolar A
- posterior lateral calcaneal A
posterior tibial pulse
diminished pulse = longstanding atherosclerosis from peripheral arterial disease
stenosis of superficial femoral and popliteal A
arterial blood clots from presence of plaques rupturing
sensory innervation
- sural N = medial sural + sural communicating, does middle
- lateral sural cutaneous (from common fib) does lateral
- saphenous n (from femoral) does medial
