During stance, knee flexion shortens the leg slightly to reduce COM rise. Which option describes this effect?

During stance, knee flexion shortens the leg slightly to reduce COM rise. Which option describes this effect?

• A. Lengthening it maximally
• B. Fixing it at full extension
• C. Shortening it slightly
• D. Moving it laterally only

Answer: (C)

During stance, a small bend at the knee shortens the leg just enough to limit how much the body's center of mass rises. This slight shortening helps keep the mass lower as weight shifts over the stance leg, improving stability and shock absorption during walking. So the description that matches this effect is shortening the leg slightly. Lengthening it maximally would raise the center of mass, fixing the knee at full extension would keep the leg long and not reduce the rise, and moving it laterally doesn’t address the vertical change in leg length.

During stance, a small bend at the knee shortens the leg just enough to limit how much the body's center of mass rises. This slight shortening helps keep the mass lower as weight shifts over the stance leg, improving stability and shock absorption during walking.

So the description that matches this effect is shortening the leg slightly. Lengthening it maximally would raise the center of mass, fixing the knee at full extension would keep the leg long and not reduce the rise, and moving it laterally doesn’t address the vertical change in leg length.