Final answer:
The normal Ground Reaction Force (GRF) at initial contact is generally located at the heel, as part of the heel-strike phase of walking. This is followed by the force transferring across the foot's arches which aid in absorbing and distributing the body's weight.
Step-by-step explanation:
The normal Ground Reaction Force (GRF) at initial contact is typically located at the heel. This is due to how the foot strikes the ground during a normal walking gait cycle. When the foot makes contact with the ground, the heel is usually the first part of the foot to touch down, especially when walking at a normal pace. This is part of the heel-strike phase, before the foot rolls forward towards the toes in a motion known as pronation, distributing the force across the midfoot and then towards the forefoot as the step continues and ends with toe-off. The design of the foot, including its arches such as the medial longitudinal arch, transverse arch, and lateral longitudinal arch, is crucial for absorbing and distributing the forces exerted on it while supporting the body's weight.