EXS 331 Exam 4: Low Back and Anterior/Posterior Hip

quadratus lumborum

flexes the spine laterally

3 erector spinae muscles

spinalis thoracis (medial), longissimus thoracis (middle), iliocostalis lumborum (lateral)

action of erector spinae muscles

hold vertebrae erect, maintain lower back posture

anterior hip muscles

iliacus, psoas minor and major

iliacus

O: iliac fossa

I: lesser trochanter of femur

A: flex thigh, laterally rotate thigh

N: Femoral

psoas major

O: L1-L5 vertebrae

I: lesser trochanter of femur

A: flex thigh

N: femoral

Iliopsoas

the name for where the iliacus and psoas major converge on the thigh (below the inguinal ligament)

posterior muscles of hip

tensor fascia latae, gluteus maximus, gluteus medius, gluteus minimus, piriformis, superior gemellus, obturator internus, inferior gemellus, quadratus femoris, obturator externus

tensor fascia latae

O: anterior iliac crest

I: tibia (via IT tract of fascia latae)

A: flex and abduct thigh

N: superior gluteal

gluteus maximus

O: posterior iliac crest, post surface of sacrum and coccyx

I: gluteal tuberosity and iliotibial tract

A: extends thigh against resistance

N: inferior gluteal

gluteus medius

O: region between anterior and posterior gluteal lines

I: greater trochanter

A: abduct and medially rotate thigh

N: superior gluteal

fascia latae

deep fascia of thigh. well developed where it meets with the tendons of the gluteus maximus and tensor fascia latae (forms iliotibial tract=inserts on the lateral condyle of tibia)

gluteus minimus

O: anterior and inferior

I: greater trochanter

A: abduct and medially rotate thigh

N: superior gluteal

piriformis

laterally rotates thigh

superior gemellus

laterally rotates thigh

obturator internus

laterally rotates thigh

inferior gemellus

laterally rotates thigh

quadratus femoris

laterally rotates thigh

obturator externus

laterally rotates thigh

posterior/external landmark between hip and thigh

post: inferior border of quadratus femoris

external: gluteal fold (round part of butt)