Patent attributes
An adjustable spring device for Walking and running is attachable to the user's footwear. The device includes an upper sole coupled to the footwear, a lower elastic sole, and a support bracket configured as a curvilinear confined band that includes a flat top fastened to the upper sole, and a concaved bottom fastened to the lower sole. The lower sole is furnished with a plurality of slots, preferably straight-lined, and aligned at a predetermined angle, cut from the periphery towards the longitudinal axis of lower sole and ending at predetermined points thereof. The slots are preferably so arranged that, if the predetermined points are linked by four straight lines extending therethrough, the four lines will form a rhomb-shaped figure having two vertexes positioned at the front and the rear ends of the lower sole. Means for variable adjustment of the support bracket are provided, creating comfortable energy exchange conditions.