Lower Limb: Muscles of thigh Flashcards
What is the significance of the compartments of the thigh?
Compartments are separated by bone, fascia & interosseous membrane
Anterior = extensors = extend the knee & flex hip
Posterior = flexors = act on hip & knee
Medial = adductors = act mostly on the hip
What is the deep fascia of the thigh & what is its signficance?
Fascia lata
extends from pelvic girdle above and is continuous with deep fascia of the leg below
Invests thigh muscles like a stocking - prevents bulging on contraction & aids venous return
What is the iliotibial tract?
Lateral thickening of the fascia lata
Functions like a tendon
The aponeurotic tendons of glut max (posteriorly) and the tensor fascia lata (anteriorly) blend with it
What is the significance of the gluteal region?
Muscles extend, rotate & abduct the thigh at the hip
hold the pelvis level in locomotion
What movements do the gluteal muscles perform in relation to the HJ?
All ABDUCT
Glut max only extends
Glut max lateral rotation
Glut min + med medial rotation
What movements at the HJ are piriformis + obtrurator interns perform?
abduct + lateral rotation
Same as glut max, minus extension
Origin, insertion & function of tensor fascia lata
Pelvic girdle to the become continuous with the iliotibial tract which runs down the lateral side of the thigh
Limits outward building of muscles
flexes, abducts & medially rotates
Origin, insertion & function of Gluteus Maximus
Superficial muscle covers all muscles of gluteal region
Arises from the dorsum of the sacrum, lateral part of coccyx & external surface of the ilium (beyond the posterior gluteal line)
Attaches to the gluteal tuberosity of proximal femur
Extension of HJ, abduction & lateral rotation
Origin, insertion & function of gluteus medius
Deep to Glut max
Arises from external surface of ilium, between anterior & posterior gluteal lines
Attaches to lateral side of greater trochanter (femur)
Abducts, medially rotates HJ
Origin, insertion & function of gluteus minimus
deep to glut max
arises from outer surface of ilium below posterior gluteal line (below medius)
attaches to lateral part of greater trochanter (femur)
Medial rotation & abduction of hip
Origin, insertion & function of Piriformis
Arises within the pelvis from the anterior aspect of the sacrum
Exits pelvis through the greater sciatic notch & attaches to the medial part of the greater trochanter
Lateral rotation & abduction of HJ
Origin, insertion & function of Obtrurator internus
Arises within pelvis from outer margins of the obtrurator foramen & internal aspect of obtrurator membrane
Exits through the lesser sciatic notch into the gluteal region
(Takes 2 gemelli muscles with it)
Attaches to medial part of greater trochanter (femur)
Abduct and laterally rotates HJ (aided by germilli muscles)
Origin, insertion & function of quadrates femoris
Arises from lateral aspect of ischium & inserts into proximal medial aspect femur
Lateral rotation only
What are the quadriceps muscles? Which are superficial & deep?
Superficial - Vastus lateralis, vastus medialis & rectus femoris
Deep - vastus intermedius
Where do the three vastus quadricep muscles originate?
The femur
Lateralis & medialis have a continuous attachment beginning at the intertrochanteric line
Intermedius is a deep muscle so arises from upper 2/3s of the shaft of femur
What is the origin of rectus femoris?
2 origins
1st from the AIIS
2nd just above acetabulum
What is the common insertion of the quadricep muscles?
Common tendon which crosses the knee joint & contains the patella bone (sesamoid bone) and then changes its name to the patella ligament to insert into the tibial tuberosity
What is different about rectus femoris compared to vastus quadriceps?
Rectus femurs has 2 origins compared to 1
Originates higher and crosses the hip joint, therefore ALSO acts to move (flex) the hip, others only cross knee joint & extend it
What common movement does the quadriceps perform?
Extension of the knee
What components of quadriceps have another INSERTION, other than quads tendon?
Vastus lateralis & medialis - insert into the respective sides of the patella
What prevents the patella laterally displacing during quadricep contraction?
Vastus medialis also inserts into the the medial margin of the patella
Reinforces capsule & prevents lateral dislocation of the patella when the quadriceps contract
Lateral femoral condyle also prevents dislocation
What are the muscles of the anterior compartment of the thigh?
Psoas major, iliacus, sartorius & quadriceps
Origin, insertion & function of psoas major
arises from posterior abdo wall from T12 - L5 vertebrae
Common tendon insertion with iliacus (iliopsoas) into the lesser trochanter
flexes the hip & maintains lumbar lordosis in standing
Origin, insertion & function of iliacus
Arises from iliac fossa
Common tendon insertion with PM - lesser trochanter
Flexes HJ & maintains lumbar lordosis in standing
Origin, insertion & function of sartorius
ASIS of ilium and inserts onto tibia (inferiomedial to tibial tuberosity)
Important when sitting cross legged + has a synergistic effect with other muscles to help flex the HJ & extend the knee
Difference in insertions between muscles of gluteal region & muscles of anterior compartment of thigh
Gluteal - greater trochanter
Anterior - lesser trochanter or tibial tuberosity
What is the main function of the muscles of the medial compartment of the thigh? What are the muscles?
Adduction at the HJ
Gracilis
pectineus
adductor longus, brevis & magnus
What are the 3 adductor muscles from superficial to deep?
Adductor longus, brevis & magnus
Origin, insertion & function of gracilis
Body of pubis and inferior aspect of pubic rami to the medial surface of the proximal tibia
Long and slender
Only one which crosses the Hip and knee joint - adduction of HJ + flexion at knee
Origin, insertion & function of pectineus
Origin along pectineal line and adjacent part of the body of the pubic bone to the base of the lesser trochanter along the linea aspra (posterior aspect of femur)
Adduction of HJ
Where do the 3 adductor muscles collectively originate & insert?
extend from the inferior pubic ramus and insert along the linear aspra (at various lengths)
What is special about adductor magnus?
It is the most expensive & deepest of the 3 named adductor muscles
It has an adductor and hamstring component, therefore 2 origins & 2 insertions
Normal adductor origin & insertion (inferior pubic rams along linea aspra - extends further than other two)
Hamstring origin from ischial tuberosity (with other hamstrings) to the adductor tubercle
What is the adductor hiatus?
Gap between the two insertions of adductor magnus between the distal linea aspra and the adductor tubercle which allows passage of vessels
What movements do the 3 named adductor muscles permit?
All adduct the HJ
Longus & magnus also medially rotate
What are the muscles of the posterior compartment?
Hamstrings:
biceps femoris, semitendinosus ad semimembranosus
What is the common origin of the hamstrings?
Ischial tuberosity
What hamstring has a 2nd origin to the common origin?
Biceps femoris
long head arises at ischial tuberosity (common)
SHORT head arises at lateral tip of linear aspra
What are the insertions of the hamstrings?
Biceps femoris inserts LATERALLY to head of fibula
Both semi’s insert MEDIALLY
Semitendinosus to medial aspect of proximal tibia
Semimemrbanosus inserts into medioposterior surface of the medial condyle of tibia
What is significant about the insertion of semimembranosus?
It is part of PES ANSERINUS - common tendon that blends into capsule of medial tibia
Sartorius, gracilis & semimembranosus
What movements do the hamstrings permit?
Flex the KNEE
Extend the HIP
Biceps femoris LATERALLY rotates and semi’s MEDIALLY rotate
