In sidelying, which placement helps prevent hip adduction and reduces lumbar rotation stress?

• A. Behind back: prevents rolling backward
• B. Under head: fill space between head/mattress
• C. Between knees: prevent hip adduction, reduces lumbar rotation stress
• D. Under top arm: prevent shoulder protraction

Answer: (C)

In sidelying, keeping the pelvis leveled and the spine from twisting is essential to reduce load on the low back. Placing a pillow between the knees prevents the upper knee from moving toward the bottom knee (hip adduction) and helps keep the legs and pelvis aligned. This alignment stabilizes the pelvis, so the lumbar spine stays nearer to neutral and is less likely to rotate, which lowers lumbar rotation stress.

The other positions address comfort or different joints but don’t specifically prevent hip adduction or reduce lumbar rotation stress: a pillow behind the back helps with stability of the trunk in some contexts but doesn’t directly control hip alignment; a pillow under the head fills space for comfort but doesn’t influence hip/pelvis positioning; a pillow under the top arm mainly limits shoulder protraction and shoulder comfort rather than affecting the hips or lumbar spine.