| A | B |
|---|
| low extremity consists of | pelvic girdle, thigh,, leg, foot |
| lower extremities are subjected to forces that are generated via... | repetitive contacts between the foot and the ground |
| lower extremities are responsible for supporting.. | the trunk and upper extremities |
| lower extremities are connected to eachother and to the trunk by the.. | pelvic girdle |
| movement in any part of the lower extremities influences movement | elsewhere in the body |
| pelvic girdle plays an important role in | supporting the weight of the body while offering mobility by increasing the range of motion in the lower extremity |
| pelvic girdle is site of attachment for | 28 trunk and thigh muscles none of which acts solely on the pelvic girdle |
| pelvis must be oriented to | place the hip joint in a favorable position for lower extremity movement |
| pelvic girdle and hip joint position contribute | significantly to balance and standing posture |
| the pelvic girdle consists of the | fibrous union of three bones: illium, ishium and the pubis |
| bones of pelvic girdle are connected by | hyaline cartilage at birth but are fully fused by age 20-25 |
| the pelvis is connected to the axial skeleton at the... | sacroiliac joint |
| describe sacroiliac joint | a strong synovial joint containing fibrocartilage and powerful ligamentous support |
| sacroiliac joint is subject to loads from | the lumbar region down and from the ground up |
| how many sets of ligaments support the right and left SI joints | three |
| even though SI joints are strongly reinforced by ligaments there is still... | movement at these joints |
| The SI joint is more..in females bc of the...and more...in males because of the.... | mobile in females bc of the greater ligament laxity and more stable in males bc of the positioning difference in center of mass |
| motion at the SI joint is best described by | sacral movements |
| trunk extension=sacral... | flexion |
| trunk flexion=sacral... | extension |
| the three movements of the pelvis are... | rotation, obliquity, tilt |
| hip joint is one of the...joints in body | largest and most stable |
| hip joint has...stability provided by... | instrinsic stability provided by its relatively rigid ball-and-socket configuration |
| hip joint has...moblity and bears...forces | has great deal of mobility, and bears relatively large forces |
| hip joint is composed of the... | head of femur and the acetabulum of the pelvis |
| acetabulum is the | concave component of the ball and socket configuration of the hip joint. |
| acetabulum is covered with | articular cartilage that thickens peripherally and laterally |
| the cavity of the acetabulum faces.. | obliquely forward, outward and downward |
| a plane through the circumference of the acetabulum at its opeing would intersect with | the sagittal plane at an angle of 40 degrees opening posteriorly and at an angle of 60 degrees opening laterally |
| acetabular cavity is deepened by the | labrum |
| femoral head is the..component of the ball and socket configuration of the hip | convex |
| femoral head forms... | 2/3 of a sphere |
| articular cartilage covering of femoral head is thickest on the... and thinnest towards... | medial-center surface and thinnest towards the periphery |
| variation in articular cartilage thickness of femoral head results in | different strengths and stiffnesses in various regions of the femoral head |
| the differences in mechanical properties from point to point on the femoral head cartilage influences... | different stresses in the joint |
| 2 angular relationships of femoral neck with femoral shaft that are important for hip function | 1. the angle of inclination of the neck with the femoral shaft in the frontal plane (neck to shaft angle) 2. the angle of inclination in the transverse plane (angle of anteversion) |
| coxa vara angle | <125 |
| normal angle | =125 |
| coxa valga angle | >125 |
| angle >12 degrees causes | a portion of the femoral head to be uncovered |
| angle<12 is...and produces | is retroversion. produces a tendency towards external rotation of the leg during gait |
| hip motion takes place in.. | all three planes: flexion-extension, abduction-adduction, internal-external rotation |
| motion of hip joint is greatest in the.. | sagittal plane. (flexion 0-140 and extension 0-15) |
| range of abduction of hip is..and adduction is.. | abduction is 0-30, adduction is 0-25 |
| external rotation of hip ranges from ...and internal rotation ranges from... | ex rotation=0-90, internal rotation=0-70 when hip joint is flexed |
| as people age they use | progressively smaller portion of the range of motion of the lower extremity joints during walking |
| ...forces act on hip joint even during simple activities | substantial |
| during two-legged stance the line of gravity of the superincumbent body passes..and, since the hip joint is stable, erect stance can be achieved by means of | posterior to the pubic symphysis and, since the hip joint is stable, erect stance can be achieved by means of stabilizing effect of the joint capsule and capsular ligaments |
| there is ...muscle activity during two-legged stance | limited |
| magnitude of force on each femoral head during two-legged stance is | 1/2 the superincumbent body weight |
| the reaction force on each hip joint during two legged stance is | 1/3 the body weight |
| during single legged stance the line of gravity...producing.. | shifts in all three planes producing torques around the hip that must be counterbalanced by muscle forces. (this increases joint reaction force) |
| the loads on the hip joint during dynamic activities are... | substantially larger than during static activities |
