In Maximum Velocity Mid flight, eccentric knee extension is described as which of the following?

In Maximum Velocity Mid flight, eccentric knee extension is described as which of the following?

• A. Eccentric knee flexion
• B. Concentric knee extension
• C. No knee movement
• D. Ankle dorsiflexion

Answer: (A)

Eccentric muscle action means the muscle lengthens while producing force to control movement. In the maximum-velocity sprint during the mid-flight portion, the leg is moving through a swing arc where the knee is actively being controlled as it flexes. The hamstrings act to decelerate knee flexion as the leg comes through the swing, lengthening under tension to keep the rate of knee movement in check and prepare for the next ground contact. That combination—knee flexion being regulated by a lengthening, force-producing muscle—fits the description of an eccentric knee flexion. The other ideas don’t describe what’s primarily happening in this phase. Eccentric knee extension would involve the knee extensors lengthening while extending the knee, which isn’t the dominant control during mid-flight. No knee movement would ignore the actual knee dynamics of the swing, and ankle dorsiflexion focuses on the ankle joint rather than the knee.

Eccentric muscle action means the muscle lengthens while producing force to control movement. In the maximum-velocity sprint during the mid-flight portion, the leg is moving through a swing arc where the knee is actively being controlled as it flexes. The hamstrings act to decelerate knee flexion as the leg comes through the swing, lengthening under tension to keep the rate of knee movement in check and prepare for the next ground contact. That combination—knee flexion being regulated by a lengthening, force-producing muscle—fits the description of an eccentric knee flexion.

The other ideas don’t describe what’s primarily happening in this phase. Eccentric knee extension would involve the knee extensors lengthening while extending the knee, which isn’t the dominant control during mid-flight. No knee movement would ignore the actual knee dynamics of the swing, and ankle dorsiflexion focuses on the ankle joint rather than the knee.