Posterior Thigh Flashcards
thigh boundaries
proximal: inguinal lig (ant) + ischiopubic ramus (med) + gluteal fold (post)
distal: knee joint
tibia
-weight bearing
-medial
-big guy
-vertical in leg an tibial plateau is horizontal
fibula
non weight bearing bc does not directly contact femur
lateral
thigh osteology
fall on ‘hip’ usually iliac crest OR greater trochanter
hip fractures usually proximal femoral fractures (neck or interchrochanteric line)
-neck of femur more likely than femoral shaft
superficial fascia
aka subcutaneous tissue or hypodermis
continuous w/ superfical fascia of abdomen/buttocks/rest of free lower limb
superficial fascia
contents
-fat (thins as distal bc greater energy demand in thigh than leg)
-superficial veins
-cutaneous nerves
-lymph vessels and nodes
females more buttocks, hips, thigh fat
fascia lata
definition
aka deep fascia of thigh
continous w/ TL fasica and deep fascia of popliteal and leg (crural)
fascia lata
structure
thick and strong w/ 3 layers of dense coll CT
-extra thick laterally w/i IT band (iliotibila tract)
limits outward muscle expansion, resists stretch and distortion
IT band
definition
aponeurosis w/i fascia lata
og @ iliac tubercule > gerdy tubercle of tibia
3 compartments
fascia lata
- posterior- knee flexors, tibial sciatic N
- anterior- knee extensors, hip flexors, femoral N
- medial- hip adductors, obturator N
separated by intermuscular septa
posterior compartment
main knee flexors w/ hamstrings (can also hip extend weakly except short head)
tibial divison of sciatic goes to everything except short head
-short head is common fib of sciatic
hamstring muscles
lateral:
1. short head biceps femoris (linea aspera > head of fibula)
2. long head biceps femoris (IT > head of fibula)
medial:
3. semimembranosous (IT>medial side proximal tibia)
4. semitendonosous (IT > medial side proximal tibia)
pes anserinus
muscles that insert:
1. sartorius (ant thigh)
2. gracilis (medial thigh)
3. semitendinosus (post thigh)
medial side proximal tibia
hamstring strain
overstretched/torn from:
-inadequate warmup
-strength imbalances
-lack of flexibility
other symps: bruising, weakness, loss of motion
graded: I (overstretch) II (partial tear) III (complete rupture tendon)
more likely tear long head than short
sciatic N split
supply posterior compartment
do not become tibial N and common fibular N until sciative splits distally @ apex of popliteal fossa
tibial N is most superficial struture in popliteal fossa
cutaneous innervation
posterior thigh
MAIN = posterior femoral cutaneous N from both divs of S1-3 + some of lateral femoral cutaneous branches
runs deep to fascia lata, parallel with sciatic
cutaneous innervation
Werning Rule
for given nerve, area where motor axons supply muscles is proximal to the skin that cutaneous axons supply
since developmentally motor axons enter first, then sensory
cutaneous branches of tibial and common fib distal
vascular supply
posterior
nothing is exclusive to posterior
hamstrings = 4 perforating A
proximal ends of semis = inferior gluteal
distal end of all hamis = small branches of popliteal and genicular A
perforating arteries
branches of deep femoral
start in anterior thigh compartment > travel posterior > pierce adductor magnus muscle and intercompartment septae
popliteal fossa
boundaries
hamstrings (thigh) and gastrocnemius (leg)
floor = popliteal surface of posterior femur and knee capsule
roof = popliteal fascia/deep fascia and skin
popliteal fossa
content
mostly fat
tibial N and common fib N
popliteal V and A (deepest)
popliteal lymph nodes and lymphatic vessels
tibial N > popliteal V > popliteal A
popliteal A
aka femoral after reaches fossa thru adductor magnus > split into anterior and posterior tibial A (in post leg compartment)
5 genicular artery branches supply knee joint, genicular anastomosis
popliteal pulse
difficult since A so deep, easier @inferior part closer to tibia
pt prone and knee semi-flexed to relax fascia and hamstrings
if weak or absent = femoral A obstruction
collateral circulation
chain of anastomoses b/t gluteal region to popliteal fosssa
- cruciate anastomosis- most important to post thigh
- genicular anastomosis- most important to popliteal fossa esp during full knee flexion
veins
- anterior + posterior tibial V > popliteal@below fossa > femoral @ant thigh
- smaller/lesser saphenous enter popliteal V in fossa, superficial vein in superficial fascia so drains superficial veins of post leg and lat foot
- perforating V travel with A
- popliteal V travel with A
lymphatics
all vessels drain into superficial inguinal lymph nodes
superficial and deep popliteal lymph nodes drain posterior and lateral leg
-send lymph to deep inguinal lymph nodes
IT band
function
- assist in maintaining typical standing posture
- reduce bending stress on femur during locomotion
-tightens when weight shifts to one side
lateral collateral ligament
distal end runs in the middle of biceps femoris (both) insertion when split into Y shape
inserts on fibular head
motor innervation
posterior compartment
MAIN = tibial division of sciatic N
common fibular div of sciatic for short head of biceps femoris
