Source: wikibot/ground-reaction-force
= Ground reaction force
{wiki=Ground_reaction_force}
Ground reaction force (GRF) is the force exerted by the ground on a body in contact with it. When a person or object exerts a force downward (for instance, when walking, running, or jumping), the ground responds with an equal and opposite force, as described by Newton's Third Law of Motion. This response is what we call the ground reaction force.