Question

what is the arthrokinematics of closed chain hip flexion (anterior pelvic tilt)?
○ anterior roll, anterior glide
○ anterior roll, posterior glide
○ posterior roll, posterior glide
○ posterior roll, anterior glide
question 21 (mandatory) (2 points)

Explanation:

In closed - chain hip flexion (anterior pelvic tilt), for the hip joint arthrokinesis: The femoral head (in closed chain, the pelvis moves relative to the femur) during anterior pelvic tilt (hip flexion in closed chain) has a posterior roll of the pelvis on the femur and an anterior glide. Wait, no, let's correct. Wait, in closed chain hip flexion (like when standing and doing anterior pelvic tilt, the femur is fixed, pelvis moves). The acetabulum (part of pelvis) relative to femoral head: during hip flexion (anterior pelvic tilt), the pelvis rolls anteriorly? No, wait, arthrokinesis: roll and glide. For hip flexion (open chain: femur moves, closed chain: pelvis moves). In closed chain hip flexion (anterior pelvic tilt), the pelvis (acetabulum) on the femoral head: the roll is posterior (wait, no, maybe I mixed up). Wait, the correct arthrokinesis for closed - chain hip flexion (anterior pelvic tilt) is posterior roll and anterior glide? Wait, no, let's recall: In hip flexion (closed chain, so the distal segment (femur) is fixed, proximal (pelvis) moves). The femoral head is in the acetabulum. When the pelvis tilts anteriorly (hip flexion in closed chain), the acetabulum (pelvis) rolls posteriorly on the femoral head and glides anteriorly. Wait, but the options: the correct option is "Posterior roll, anterior glide"? Wait, no, maybe I made a mistake. Wait, let's think again. In closed - chain hip flexion (anterior pelvic tilt), the movement of the pelvis (acetabulum) relative to the femoral head: the roll is posterior and glide is anterior? Wait, no, the other way: when the femur is fixed (closed chain), and the pelvis tilts anteriorly (hip flexion), the acetabulum (pelvis) rolls anteriorly? No, I'm confused. Wait, the correct answer for closed - chain hip flexion (anterior pelvic tilt) arthrokinesis is posterior roll and anterior glide? Wait, the options: the fourth option is "Posterior roll, anterior glide". Wait, let's check the concepts. Arthrokinesis: roll and glide. For a joint, roll is in the direction of movement, glide is in the direction of the concave surface (for hip, acetabulum is concave, femoral head is convex). In closed - chain hip flexion (anterior pelvic tilt), the pelvis (acetabulum, concave) moves on the femoral head (convex). The movement of the pelvis (anterior pelvic tilt) is hip flexion, so the roll of the acetabulum (pelvis) is posterior (because the convex surface (femoral head) would have a roll in the direction of movement, but in closed chain, pelvis moves). Wait, maybe the correct answer is "Posterior roll, anterior glide" (the fourth option).

Answer:

D. Posterior roll, anterior glide (assuming the options are labeled A - D as first: A. Anterior roll, anterior glide; B. Anterior roll, posterior glide; C. Posterior roll, posterior glide; D. Posterior roll, anterior glide)