Generation and attenuation of transient impulsive forces beneath the foot: a review.

At the end of the swing phase of gait, the moving foot generates a transient force, due to the exchange of momentum as it contacts the ground. This review article examines the transient, which is known as the heelstrike in walking and the footstrike in running. The resulting 'shock wave', which passes up the limb, may produce damage, leading to degenerative joint disease and a variety of other pathologies. Protection against transient forces is provided by limb positioning at initial contact, by the anatomical heel pad, by materials used in shoe construction and by the use of viscoelastic shoe inserts.