In the forward support phase of maximum velocity sprinting, which two aspects are minimized?

In the forward support phase of maximum velocity sprinting, which two aspects are minimized?

• A. Horizontal braking forces and vertical displacement
• B. Horizontal propulsion and vertical acceleration
• C. Vertical displacement and horizontal propulsion
• D. Horizontal forces and gravity

Answer: (A)

In the forward support phase of maximum velocity sprinting, the focus is on wasting as little energy as possible on actions that don’t push you forward. The two aspects minimized are horizontal braking forces and vertical displacement. Reducing braking forces means the ground reaction force during foot contact has a smaller backward component, so you lose less speed when the foot is on the ground. Reducing vertical displacement means the center of mass moves less up and down during stance, which lowers vertical work and keeps more of the force from the ground contributing to forward motion. In this phase, you’d rather maximize forward propulsion while keeping these wasteful movements to a minimum.

In the forward support phase of maximum velocity sprinting, the focus is on wasting as little energy as possible on actions that don’t push you forward. The two aspects minimized are horizontal braking forces and vertical displacement. Reducing braking forces means the ground reaction force during foot contact has a smaller backward component, so you lose less speed when the foot is on the ground. Reducing vertical displacement means the center of mass moves less up and down during stance, which lowers vertical work and keeps more of the force from the ground contributing to forward motion. In this phase, you’d rather maximize forward propulsion while keeping these wasteful movements to a minimum.