Question

During gait, a flexion moment at the knee joint results in the need for which muscles to contract and in what capacity?

A) Knee flexors, concentrically.
B) Knee extensors, concentrically.
C) Knee flexors, eccentrically.
D) Knee extensors, eccentrically.

Answer 1

During gait, a knee flexion moment requires the eccentric contraction of the knee extensors, specifically the quadriceps femoris, to control and slow down the flexion of the knee joint.

Step-by-step explanation:

During gait, a flexion moment at the knee joint requires the contraction of the knee extensors in an eccentric manner. Eccentric contraction involves the muscle elongating while under tension, often to control the descent or deceleration of a body part. In this case, as the knee joint flexes, the quadriceps femoris group - which serves as the knee extensors - works in opposition to the flexion motion, to slow down and control the motion of bending the knee. This action is necessary to avoid collapsing by controlling the rate of knee flexion during gait. Therefore, the correct answer is D) Knee extensors, eccentrically.