A jumping shoe attachment controlled by the normal heel to toe distribution of the weight and metatarsal thrust of a person as they stride or jump. Said attachment performs by comprising in combination:
- a) a foot encasement of a durable, lightweight, and rigidly formed material which can allow for the normal motions of the user's foot while securely supporting it. Said encasement is to serve as a platform spaced generally parallel above a base plate. Said foot encasement is to have a point, located above the user's heel and behind their ankle, for the upper portion of a shock absorber to pivotally connect. Said foot encasement is to have an attachment point representing the pivot center of the user's foot, to which the two upper arms of an angle spring device are to pivotally connect. Said foot encasement is to also have an attachment point, for the upper end of a resilient compression device to firmly connect, under the ball area of the user's foot.
- b) an angle spring device (hereafter referred to as torsion springs) pivotally secured under the central pivot point of the foot encasement. The angle spring's upper arms extend rearward, horizontally when idle, from said central pivot point on either side of the user's heel and allow the heel to pass. The lower arms of said torsion springs extend down and attach to the base plate of the apparatus. At a predetermined point, between said attachment to the foot encasement, and the elbow of the angle spring, the lower end of the shock absorber is pivotally secured.
- c) shock absorber(s) pivotally secured at its upper end to said foot encasement in a manner that biases said foot encasement towards a generally horizontal position. Said shock absorber is pivotally secured, at a predetermined point on its lower end, to said attachment point on the angle spring arms.
- d) a device with coil spring properties attached to the underside of the foot encasement and the top of said apparatus base in a manner that provides spring to the ball of the foot and may or may not impose a predetermined maximum span between said foot encasement and said base plate.
- e) a base plate of a durable, lightweight, and rigidly formed material on its upper surface and a means of attachment to a footwear outsole suitable to the user's intended application of the propulsion footwear.
- f) said shock absorber, said torsion spring, and said coil spring cyclically arranged to sequentially absorb the forces of impact and the users exertion, while generating torsion buildup throughout a rocking heel to toe motion, and then impart an amplified metatarsal thrust to user.