What type of contraction do the tibialis anterior, EDL, and EHL exhibit just prior to and during heel strike?

The tibialis anterior, extensor digitorum longus (EDL), and extensor hallucis longus (EHL) primarily exhibit eccentric contractions just prior to and during heel strike. This is because these muscles are responsible for controlling the dorsiflexion of the ankle as the foot prepares to make contact with the ground. As the heel strikes, these muscles lengthen under tension, which is the hallmark of an eccentric contraction. This action helps to decelerate the foot and control the position of the ankle, allowing for a smooth transition into the next phase of gait.

By performing an eccentric contraction, these muscles prevent excessive plantarflexion and stabilize the foot, reducing the risk of injury and ensuring proper alignment. Other types of contractions, such as isometric or concentric, do not accurately describe the role these muscles play during this specific phase of gait, as those contractions involve different mechanisms of muscle movement.