During loading response, the internal muscle action at the knee is primarily what?

During loading response, the internal muscle action at the knee is primarily what?

• A. Concentric hamstrings only
• B. Isometric abductors
• C. Eccentric plantarflexors
• D. Eccentric quadriceps

Answer: (D)

The knee is absorbing shock during loading response, and the knee tends to bend as weight is accepted. The quadriceps act eccentrically here—lengthening under tension—to control that knee flexion and dampen the impact. This eccentric contraction stabilizes the joint and smooths the transition into midstance. Other options don’t fit this phase: the hamstrings aren’t the primary group controlling knee flexion at this moment, hip abductors act at the hip, and plantarflexors work at the ankle. So the best description is eccentric quadriceps.

The knee is absorbing shock during loading response, and the knee tends to bend as weight is accepted. The quadriceps act eccentrically here—lengthening under tension—to control that knee flexion and dampen the impact. This eccentric contraction stabilizes the joint and smooths the transition into midstance. Other options don’t fit this phase: the hamstrings aren’t the primary group controlling knee flexion at this moment, hip abductors act at the hip, and plantarflexors work at the ankle. So the best description is eccentric quadriceps.