Lecture 6 (test 2): Hip Musculature

Question 1

the lumbar plexus supplies what area of the body

Answer 1

anterior/medial thigh

Question 2

the sacral plexus supplies what area of the body

Answer 2

posterior lateral hip and posterior thigh and entire lower leg

Question 3

anterior capsule is innervated by

Answer 3

femoral and obturator nerves from the lumbar plexus

Question 4

posterior capsule is innervated by what

Answer 4

sacral plexus

Question 5

roots of femoral n

Answer 5

L2-4

Question 6

the femoral n supplies what

Answer 6

most hip flexors
-psoas
-iliacus
-sartorious
-pectineus
-quads

all knee extensors

sensory to anterior medial thigh

Question 7

obturator n roots

Answer 7

L2-4

Question 8

obturator n supplies what

Answer 8

hipp adductirs

obturator externus

sensory to medial thigh

Question 9

nerves that come of sacral plexus

Answer 9

superior gluteal n
inferior gluteal n
n to piriformis
scaitic n
n to obturator internus and gemellus sup
n to quadratus femoris and gemellus inf

Question 10

primary muscles that flex the hip

Answer 10

iliopsoas
sartorius
tensor fascia latae
rectus femoris
adductor longus
pectineus

Question 11

secondary muscles that flex the hip

Answer 11

adductor brevis
gracilis
anterior fibers glut min

Question 12

describe iliopsoas and psoas major

Answer 12

large/long

iliacus= in iliacus fossa/over SI joint

psaos major = TP T12/discs (blends with diaphragm)

both muscles blend anterior to the femoral head before attaching to the lesser trochanter

Question 13

what is “internal snapping hip”

Answer 13

distal abrasion at iliopubic eminence region

Question 14

actions of iliopsoas

Answer 14

prominent femoral on hip flexor and flexor of trunk/pelvis over fixed thighs

swing phase of walk/run

frontal plane stability of lumbar spine (bilateral contraction) with unilateral leg SLR

Question 15

where is psoas minor, where does it attach, and what does it do

Answer 15

directly anterior to major

present in 60-65%

attaches on T12/L1 bodies medial to acetabulum and iliac fascia

may help stabilize the position of the underlying psoas major (prevents “bowstring”)

Question 16

describe the sartorius (location, characteristics, and actions)

Answer 16

longest muscle in body.
“tailor’s muscle”
runs form ASIS to medial proximal tibia at pes anserine

actions = hip flexion, ER, and abd

Question 17

innervation of sartorious

Answer 17

femoral n (posterior division of L2 and L3)

Question 18

attachment and action of tensor fascia latae

Answer 18

from ilium to IT band (short)

flexor/abd of hip

*IR from ER only

Question 19

TFL innervation

Answer 19

superior gluteal n

L4, L5, S1

Question 20

rectus femoris attachments and function

Answer 20

between sartorius and TFL

from AIIS and sup rim of acetabulum/capsule to the tibia

1/3 isometric torque at hip

primary knee extensor

Question 21

innervation rectus femoris

Answer 21

femoral n

Question 22

describe pelvic on femoral hip flexion: anterior tilt

Answer 22

a force couple with femurs fixed: hip flexors and trunk extensors (stretch flexors, contract extensors??)

lordosis increases

load on facets increase anterior shear force of L5/S1

Question 23

describe femoral on plevic hip flexion

Answer 23

often simultaneous with knee flexion to shorten limb

mod to high power coactivation of hip flexors and abdominals

Question 24

what happens if the core is not properly activated during activation of the hip flexors

Answer 24

reduced activation of core causes a marked anterior tilt of pelvis with contraction of hip flexors

Question 25

primary muscles that adduct the hip

Answer 25

pectineus adductor longus gracilis adductor brevis adductor magnus

Question 26

secondary muscles that adduct the hip

Answer 26

biceps femoris (long head) glut max (inf fibers) quadratus femoris obturator externus

Question 27

what are the 3 layers of muscles for hip adduction

Answer 27

superficial: pectineus, add longus, and gracilis middle: adductor brevis deep: add magnus- horizontal and oblique (60% mass)

Question 28

describe the muscle function of hip add

Answer 28

produces force in all 3 planes primarily in sagittal and frontal

Question 29

frontal plane function of adductors

Answer 29

femoral on pelvis and pelvis on femoral i.e. kicking a soccer ball R leg is femoral on pelvis add and L is pelvis on femoral add eccentric activation of the L glut med to help control the velocity and extent of the drop of the adducting L hip

Question 30

sagittal plane function of the adductors

Answer 30

adductor magnus: post fibers are powerful hip extensors outside 40-70 degrees flexion, adductors can be powerful flexors or extensors hip near full flexion = add assist in ext hip near full ext = add assist flexors **important in high power cyclical motions like sprinting, cycling, deep squat, etc

Question 31

what muscles IR the hip

Answer 31

anatomical position = no perfect positioned IRs secondary rotators = ant fibers glut min/med, TFL, add longus/brevis, pectineus

Question 32

how does flexion affect the IRs torque

Answer 32

60-90 degrees hip flexion the IRs torque changes due to angle i.e. piriformis becomes IR past 60 degrees

Question 33

function of IRs during gait

Answer 33

durign stance they RT the pelvis on femur

Question 34

what is the clinical significance of an IR torque bias with greater hip flexion

Answer 34

related to excessively internally roatates and flexed crouched gait pattern in some people poor control/weakness of hip extensors= typically flexed posture of the hip exaggerates the IT torque potential of many muscles of the hip

Question 35

primary hip extensor muscles

Answer 35

glut max hamstrings post head of adductor magnus

Question 36

secondary hip extensor muscles

Answer 36

middle and post fibers of glut med and ant fibers of adductor magnus

Question 37

after 70 degrees of hip flexion mist adductor muscles can assist with what

Answer 37

hip extension

Question 38

glut max innervation

Answer 38

inferior gluteal n

Question 39

hamstrings innervation

Answer 39

sciatic n (tibial L5-S2)

Question 40

post head of adductor magnus innervation

Answer 40

obturator n (posterior division; L2, 3, 4)

Question 41

attachments of glut max

Answer 41

illium sacrum coccyx ST and post SIJ lig TL fascia runs to ITB, TFL, and gluteal tuberosity on femur

Question 42

functions of glut max

Answer 42

EXT ER stabilizes SIJ

Question 43

attachments and functions of hamstrings

Answer 43

IT to tibia and fibula extend hip and flex knee

Question 44

what happens with pelvic on femoral hip ext: posterior pelvic tilt

Answer 44

force couple with femurs fixed hip extensors and abdominal muscles lordosis reduced forward lean of body

Question 45

2 phases of forward lean of body

Answer 45

primarily uses hamstrings; forward lean increases the moment arm of HS which increases passive tension in HS 1: slight: COG still in pelvic girdle; minimum activation from glut max and HS 2: significant lean: COG out from hips; increase HS use but not glut max

Question 46

describe femoral on pelvic hip ext

Answer 46

typically a large and powerful ext torque rapid accelerations

Question 47

why is a large knee ext torque needed by RF during femoral on pelvis hip ext

Answer 47

1: external load and BW cause knee flexion torque 2: to counter string knee flexion torques creased by HS and gastroc large muscle contribution also creates an anterior tilt/hip flexion and the glut max/adductor magnus must match and exceed that torque to create hip ext and climb the hill

Question 48

primary adbuctors of the hip

Answer 48

glut med glut min TFL

Question 49

characteristics of glut med

Answer 49

goes from ilium to greater trochanter largest at 60-65% of abdcutirs excellent leverage has anterior/middle/posterior portions

Question 50

characteristics of glut min

Answer 50

deep and anterior to medius from ilium to greater trochanter blends with capusle hip joint (may prevent impingement)

Question 51

secondary abductors of hip

Answer 51

piriformis sartorius rectus femoris ant/sup fibers of glut max

Question 52

why might abductors of the hip require neutralization to get pure abduction

Answer 52

all have either IR or ER actions and thus require neutralization to get pure abd

Question 53

how do hip abductors provide frontal plane stability with walking

Answer 53

stance phase abductors stabilize pelvis over a fixed femur to keep pelvis from dropping

Question 54

how do hip abductors produce compression force at the hip

Answer 54

seesaw with femoral head as a fulcrum need static rotatory equiliibrium every step = force of joint is combined forces of abd muscles and body weight with an equal and opposite JRF

Question 55

when does max (torque) capacity of hip abductors occur? weakest?

Answer 55

when adducted just beyond neutral which is the position of unilateral stance also where ITB has some passive tension due to a slight stretch (femur on pelvis adduction) weakest is at 40 deg

Question 56

primary ERs of hip

Answer 56

glut max 5 of the 6 short external rotators

Question 57

secondary ERs of hip

Answer 57

post fibers of glut med and min obturator externus sartorius LH biceps femoris

Question 58

nerves of the ERs of hip

Answer 58

superior gluteal obturator n n to piriformis n to obturator internus n to obturator externus

Question 59

what are the 6 short external rotators

Answer 59

piriformis obturator internus gemellus superior gemellus inferior quadratus femoris obturator externus

Question 60

how does pelvic on femoral RT occur

Answer 60

ER muscles RT pelvis over the femur R LE planted and ER contraction will RT the anterior side of the pelvis and trunk to the L (contralateral to the rotators)

Question 61

what muscle actions may occur with "planting and cutting" in sports

Answer 61

ex: glut max can ER and ext for turn and push off adductors/IRs can eccentrically decelerate but can be subject to strain