lecture 6 hip musculature Flashcards
What does the lumbar plexus innervate
anterior/med thigh
What does the sacral plexus innervate?
post/lat hip and post thigh
entire lower leg
What does the femoral nerve innervate?
- most hip flx
- all knee ext
- sensory to ant-med thigh
What does the obturator nerve innervate?
- hip abd
- obturator externus
- sensory med thigh
What makes up the sacral plexus?
- superior gluteal nerve
- inferior gluteal nerve
- nerve to piriformis
- sciatic nerve
- nerve to obturator internus and gemellus superior
- nerve to quadratus femoris and gemellus inferior
What muscles do hip flx?
- iliopsoas
- sartorious
- TFL
- rectus femoris
- adductor longus
Where does the iliopsoas run? What does it do?
- iliacus: iliacus fossa to over SIJ
- psoas major: TP T12/discs
blend anterior to femoral head before attaching to lesser trochanter - internal snapping hip - distal abrasion at iiopubic eminance
- femoral on hip flx and flx of trunk/pelvis over fixed thighs
- swing phase of walk/run
- frontal plane stability of lumbar spine bilat contraction
What innervated ilipsoas?
anterior ramus of the spinal nerve L1
What does the psoas minor do?
- directly anterior to major
- present in 60-65%
- T12/L1 bodies to medial to acetabulum and iliac fascia
- stabilize the position of the psoas major
Where does the sartorious do? Where does it run?
runs asis to medial prox tibia at pes anserine
- hip flx, er, abd
- longest muscle in the body
What does the TFL of the thigh attach to? What does it do?
- glut max and TFL attachments
- forms fascial sheets of intermusular septa
- ITB forms as thickened deeper portion
Where does the rectus femoris run? Where does it attach? What does it do?
- between sartorius and TFL
- aiis and superior rim of acetabulum/capsule to tibia
- primary knee ext
- femoral nerve
What does the adductor longus do?
contributes to the flexion of the extended thigh as well as the extension of the flexed thigh
What does the pectineus do?
Assists in hip add and flx
What is anterior tilt during pelvis-on-femoral hip flx?
- force couple with femurs fixed, hip flx and trunk ext
- lordosis, loads increases on facets, increase anterior shear force L5/Sq
What is femoral-on-pelvis hip flexion?
- simultaneous with knee flx to shorten limnb
- mod to high power coactivation of hip flx and abdominals
What happens with normal activation of the abdominal muscles?
pelvis is stabilized and prevented from anterior tilting by the strong inferior pull of the hip flexor muscles
What happens with reduced activation of the rectus abdominus?
contraction of the hip flexor muscles causes an anterior tilt in the pelvis
What muscles do adduction of the hip?
- pectineus
- adductor longus
- gracilis
- adductor brevis
- adductor magnus
What are the three layers of the hip adductors?
- superficial: pectineus, adductor longus, gracilis
- middle layer: adductor brevis
- deep layer: adductor magnus, horizontal and oblique
What do the muscular forces of the hip do during adduction?
- produces forces in all 3 planes
- primary sagittal and frontal
Weakness of which muscle may place valgus stress on the lE and risk on the ACL?
glute med
What motions are the adductors important in ?
high power cyclical motions (sprinting, cycling, deep. squat, running up a hill)
- susceptible to injury/soreness/ with running/jumping/changing directions
What are the IR of the hip during anatomical position?
NONE
What are the secondary IR of the hip?
- ant fibers glut min/med
- TFL
- adductor longus/brevis
- pectineus
When do the IR increase in torque?
during 60-90 degrees of hip flx due to angle change, piriformis even becomes IR past 60 deg
What is the function of the IR of the hip during gait?
during stance they rotate the pelvis on the femur
What can happen in those with CP with IR of the hip?
- Excessive IR and flexion
What are the primary ext of the hip?
- glut max
- hamstrings
- posterior head of add magnus
What are the secondary ext of the hip?
- mid and post fibers of glut med and anterior fibers of add magnus
When can most adductors assist with flx?
- > 70 degrees flexion
Where does the glut max run?
- ilium/sacrum/coccyx/ST and posterior SIJ ligs/TL fascia TO IT band/TFL and glut tuberosity on femur
What does the glut max do?
- extensor and ER
- stabilized SIJ, lumbar region secondary to legs/fascial attachments
Where do the hamstrings run? What do they do?
- IT to tibia and fibula
- extend hip and flx knee
What force couple happen during pelvis-on-femoral hip ext?
- hip ext and abdominals
- lordosis reduced
What are the two phases of the forward lean of the body?
- slight - COG still in pelvic girdle, min activation from glut max and HS
- significant lean: COG out from hips; increase HS but not glut max
What are the primary abductors?
- glut med
- glut min
- TFL
Where does glut med run?
- ilium to gtr trochanter, largest @ 60-65% of abductors, excellent leverage, ant/middle/post portions
Where does glut min run?
- deep and anterior to med, ilium to gtr trochanter, blends with capsule hip joint
What do all muscles that do abduction also do?
IR or ER and need neutralization to get pure abd
What is the hip abductor mechanism providing?
- frontal plane stability with walking
- production of compression force at the hip
When does the max capacity of hip abductors occur?
when abducted just beyond neutral (unilat stance)
When are hip abd weakest?
40˚
What muscles do ER of the hip?
- glut max
- 5 of the 6 short er
What are the six short external rotator?
- piriformis
- Obturator internus
- gemellus superior
- gemellus inferior
- quadratus femoris
- obturator externus
What is important about ER during pelvic-on-femoral rotation?
- ER muscles rotate the pelvis over the femurs
- rotate the anterior side of the pelvis and trunk to the contralateral side of the rotators
