The major quadriceps burst shortly after heel contact controls what? (rephrase)

The major quadriceps burst shortly after heel contact controls what? (rephrase)

• A. Hip extension
• B. Knee flexion in the first 10% of gait
• C. Ankle dorsiflexion during midstance
• D. Pelvic rotation only

Answer: (B)

In early stance after heel contact, the body begins to load the leg, and the knee would tend to flex under that weight. The major quadriceps burst then acts to eccentrically contract and control that knee flexion, preventing the knee from buckling and stabilizing the limb as the body weight is accepted. This timing aligns with the first about 10% of the gait cycle, when weight is being loaded and knee control is crucial. The other options don’t fit this primary role: hip extension is driven by hip extensors later in stance, ankle dorsiflexion during midstance involves the ankle muscles, and pelvic rotation isn’t the main function of the quadriceps. So the burst is about controlling knee flexion in the first portion of gait.

In early stance after heel contact, the body begins to load the leg, and the knee would tend to flex under that weight. The major quadriceps burst then acts to eccentrically contract and control that knee flexion, preventing the knee from buckling and stabilizing the limb as the body weight is accepted. This timing aligns with the first about 10% of the gait cycle, when weight is being loaded and knee control is crucial. The other options don’t fit this primary role: hip extension is driven by hip extensors later in stance, ankle dorsiflexion during midstance involves the ankle muscles, and pelvic rotation isn’t the main function of the quadriceps. So the burst is about controlling knee flexion in the first portion of gait.