4.6 Muscles Crossing hip and knee joints Flashcards
What is the role of the differnt muscles in knee joints?
Most anterior (quads): flex femus at hip, extend leg at knee
posterior (hamstring): extend thigh, flex leg (backswing walking)
Medial: adducts: all adduct
*all 3 groups enclosed by fascia lata
prime mover of hip joint flextion
Thigh flexors (pass in front of hip joint)
include: illiopsoas (iliacus and psoas major)
Iliopsoas
composite of iliacus and psoas major
- fibers pass under inguinal ligament to insert via common tendom on femur
iliacus
- more laterial of iliospaoas
O: iliac fossa and crest
I: femur
*prime mover for flexing thigh or flexing trunk of thigh during bow
Psoas major
*psoa = loin muscle
- longer, thicker and more medial of iliospoas muscles
O: lumbar vertebrae and T12
I: femur
*like iliacus, also prime mover for flexing thigh or trunk on thigh
also flexes vertebral column laterally
Sartorius
- straplike superficial muscle running obliquly across anterior surface of thigh
- Longest muscle in body - crosses hip and knee joints
O: iliac spine
I: tibia
*flexes, abducts and laterally rotates thigh
What muscles are thigh extensors, abductors and rotators?
Gluteus medius, gluteus minimus, gluteus maximum
- piriformis
- obturator externus and internus
Gemellus
Gluteus maximus
- O: dorsal ilium ,sacrum and coccyz
I: femur, iliotibial tract
*major extenor of thigh - most effective then thigh is flexed
* laterally abducts and rotates thigh
Gluteus medius
*site for intramesuclar inj
- O: ilium
I: femur
*abducts and medially rotates thigh important in walking)
*holds pelvis
Gluteus minimus
- small and deep
O: ilim
I: femur
*same function of glut medius - abducts and medially rotates thigh
What muscles are the lateral rotatators?
Piriformis
obturator externus
obturator internus
Gamellus
Quadratus femoris
Piriformis
Piri = pear, formis = shape
0 located on posterior aspect of hip joint, inferior to glu min
- O: sacrum
I: femur
*rotates extended thigh laterally - helps abduct
Obturator externus
- flat, trangular muscle, deep in supermedial aspect of thigh
- O: margins of obturator foramen
i: femur
*same action as piriformis: rotates extended thigh laterally and helps to abduct thigh, stabilizes hip joint
obturator internus
- surrounds obturator foramen within pelvis
O: obturator foramen
I: greater trochanter
(same function as piriformisa & obtur ext: rotates extended thigh laterally and help abduct thigh when hip is flexed)
Gamellus
- has a superior and inferior *gemin = twin
- O: ischial spine
I: femus
*same function as piriformis, and obturators: rotates and extends thigh laterally, helps abduct thigh when hip is flexed
Quadratus femoris
- short, thick and most inferior lateral rotator muscle
- extends laterally from pelvis
O: ischial tuberosity
I: femur
*rotates thigh laterally and stablizes hip joiny
Quadriceps femoris
- arise from four seperate heads, form flesh of front and side of thigh
- insert into quadricepts tendon that inserts into patella via patellar ligament into tibial tubersosity
*Powerful knee extensor
Rectus femoris
*rectus = straigh, femoris = femur
- superficial muscle
- O: iliac spine
I: patella and tibial tuberosity
*extends leg and flexes thigh at hip
Vastus lateralis
- largest head of the quadricepts femoris, forms lateral aspect of thigh
*common IM inj site
- O: linae aspera (femur)
I: patella and tibial tuberosity
*extends and stabilizes the leg
Vastus mediallis
* part of quadricepts femoris
- forms inferomedial aspect of thigh
O: linea aspera (femur)
I: patella and tibial tuberosity
*extends leg
Vastus intermedius
*part os quadricepts femoris
- obscured by rectur femoris, lies between vastus lateralis and vastus medialis on anterior thigh
O: femur shaft
I: patella and tibial tuberosity
*extends leg
Tensor fascia lata
Tensor: to make tense, fascia: band, lata: wide
0 enclosed between fascia laters
O: iliac crest
I: iliotibial tract (thickened alteral protion of Fascia lata)
*steadies leg an trunk on thihg by making iliotibial tract taut
*flexes and abducts thigh, rotates thigh medially
What are the hamstrings, what muscles are part of them
- fleshy muscles posterior thigh
*cross hip and knee joints
*prime movers of thigh extension and knee felxion
contains: biceps femoris, semitendinous and semimembransous
Biceps femoris
- most lateral muscle of hamstrings, arises from two heads
O: ischial tuberosity (long head) and femur (short head)
I: fibula and tibia
*extends thigh and flexes leg,
*laterally rotates leg esp when knee is flexed
Semitendinosus
- part of hamstrings
- lies ledially to biceps femoris
- largely tendinous, but also quite fleshy: long and slender
O: ischial tuberosity
I: tibial shaft
*extends thigh and flexes leg
*w/ semimembranosus medially rotates leg
Semimembranous
*muscle of hamstrings
- deep to semitendinosus
O: ischial tuberosity
I: tibia
*extends thigh and flexes leg
*medially rotates leg w/ semitendinosus
