Knee flexors during loading response are mostly active at which joint?

Knee flexors during loading response are mostly active at which joint?

• A. Hip
• B. Ankle
• C. Subtalar joint
• D. MTP joint

Answer: (A)

During loading response, the knee flexors (the hamstrings) cross two joints, but the leg is being controlled mainly to absorb impact rather than to produce knee movement. The knee itself is stabilized by the knee extensors (quads) eccentrically controlling knee flexion, so the knee flexors aren’t driving knee motion here. Because these muscles cross the hip as well, their functional action in this phase is at the hip: they help extend the hip and stabilize the pelvis as weight is borne by the limb. So, the knee flexors act most at the hip during this part of the gait cycle. The other joints listed are not where their primary action occurs in this phase.

During loading response, the knee flexors (the hamstrings) cross two joints, but the leg is being controlled mainly to absorb impact rather than to produce knee movement. The knee itself is stabilized by the knee extensors (quads) eccentrically controlling knee flexion, so the knee flexors aren’t driving knee motion here. Because these muscles cross the hip as well, their functional action in this phase is at the hip: they help extend the hip and stabilize the pelvis as weight is borne by the limb. So, the knee flexors act most at the hip during this part of the gait cycle. The other joints listed are not where their primary action occurs in this phase.