Unit 3 Lecture Flashcards
which 4 bones compose the pelvic girdle?
- sacrum
- coccyx
- 2 hip bones (ilium, ischium, pubis)
describe the sacrum
- 5 fused vertebrae
- concave anterior surface
- BASE superior surface
- PROMONTAORY ridge projecting along anterior edge of body of S1
- ALA lateral flared wings, fused transverse processes
name the 3 joints of the pelvic girdle
- lumbosacral
- sacroiliac
- symphysis pubis
describe the lumbosacral joint
- L5 & S1
- bodies are separated by an intervertebral disc
- iliolumbar ligament: transverse process of L5 to posterior portion of iliac crest
- lumbosacral ligament: transverse process of L5 to ala of sacrum
describe the lumbosacral angle
- optimal is approximately 30 degress
- increases with lordosis & causes shearing stresses of L5 on S1 to increase
- decreases along with the decrease of lordosis
describe the SI (sacroiliac joint)
- synovial & nonaxial plane joint between the sacrum & ilium
- articular surfaces are irregular which helps to “lock the surfaces together”
- designed for great stability & to transmit weight from upper body through the vertebral column to the hip bones
describe the motions of the SI joint
only occurs in association with other joint motions
- NUTATION: sacral flexion
- occurs with trunk flexion or hip extension
- the superior sacrum (base) moves anteriorly & inferiorly
- the inferior sacrum & coccyx move posteriorly
- COUNTERNUTATION: sacral extension
- occurs with trunk extension or hip flexion
- superior sacrum moves posteriorly
- the tip of the coccyx moves anteriorly
these motions are important during childbirth
describe the interosseus SI ligament
- deepest and strongest SI
- connects the tuberosities of the ilium & sacrum
describe the pubic symphysis
- held together primarily by 2 ligaments: the superior & inferior pubic ligaments
describe a false & true pelvis
- FALSE: no pelvic organs within (L4 and L5 area)
- TRUE: between the pelvic inlet & oulet & contains portions of the GI tract, urinary tract, and some reproductive organs (in females: the birth canal)
describe the male & female pelvis
- MALE:
- superior opening is more heart shaped
- pelvic cavity is longer and funnel shaped
- FEMALE:
- pelvic arch is wider & more rounded
- pelvic cavity is greater
- pelvic cavity is shorter
describe pelvic tilt
- anteriorly: hip flexion & lumbar hyperextension
- posteriorly: hip extension & lumbar flexion
- lateral: pelvis moves as a unit
describe pelvic rotation
- pelvis moves on the WB hip joint
which 3 bones form the hip?
ilium, ischium, & pubis
what kind of joint is the hip?
ball & socket (pubis is concave, femoral head is convex)
triaxial joint
what are the motions of the hip?
- flexion, extension, & hyperextension
- abduction & adduction
- LR & MR
name the important bones/landmarks of the hip
- iliac fossa
- iliac crest
- ASIS, AIIS, PSIS
- ischial tuberosity
- ramus of ischium & ramus of pubis
- acetabulum
name and describe the ligaments of the hip joint
cross the joint in a spiral fashion to attach to femoral neck
- ILIOFEMORAL: limits hyperextension
- PUBOFEMORAL: limits hyperextension & abduction
- ISCHIOFEMORAL: limits hyperextension & MR
define coxa, vara, valga, & genu
- coxa: refers to the hip
- vara/varus: turned inward
- valga/valgus: turned outward
- genu: refers to the knee
what is the angle of inclination?
- the angle between the shaft& neck of the femur in the frontal plane
- normal is 125 degrees (170 at birth)
coxa valga angle is greater than 125 (creates a straighter/longer limb)
coxa vara angle is less than 125 (creates a more bent/ shorter limb)