During midstance, the quadriceps act concentrically to do what?

During midstance, the quadriceps act concentrically to do what?

• A. Flex the knee and unload the limb
• B. Dorsiflex the ankle
• C. Pronate the foot
• D. Extend the knee and support body weight

Answer: (D)

During midstance the body’s weight sits over the stance leg and the knee is near full extension. The quadriceps contract concentrically to extend the knee, helping to lock and stabilize the joint so the leg can bear and transfer body weight as you progress over the foot. This action keeps you upright and provides a solid pillar for the body's weight during this part of the gait cycle. The other options don’t fit because ankle dorsiflexion and foot pronation are controlled by different muscles, and bending the knee would reduce the knee’s ability to support weight during this phase.

During midstance the body’s weight sits over the stance leg and the knee is near full extension. The quadriceps contract concentrically to extend the knee, helping to lock and stabilize the joint so the leg can bear and transfer body weight as you progress over the foot. This action keeps you upright and provides a solid pillar for the body's weight during this part of the gait cycle. The other options don’t fit because ankle dorsiflexion and foot pronation are controlled by different muscles, and bending the knee would reduce the knee’s ability to support weight during this phase.