Shoe having improved cushioning and propulsion

A shoe comprising a shoe portion and a single sole, the shoe portion comprising a forepart, a median zone, and a rear portion,

• the sole comprising:
• a first portion linked to the rear portion and the median zone of the shoe portion of the shoe, and
• a second portion secured to the forepart of the shoe portion of the shoe,
• the first portion of the sole and the second portion of the sole being pivotally connected together with a first horizontal swivel pin adapted to be located substantially under the natural joint between the forepart and the rear portion of the foot,
• characterized in that the second portion of the sole extends to the rear of said first swivel pin forming a lever having a front arm and a rear arm in a proportion substantially equal to ⅔ and ⅓, with about ⅔ of the second portion of the sole being linked to the forepart of the shoe portion forming the front arm of the lever and about ⅓ of the second portion of the sole extending to the rear of the first swivel pin forming the rear arm of the lever and being projected to the rear in the same plane as that of the front arm of the lever and kinetically secured to the front arm of the lever,
• the first swivel pin forming the fulcrum of the lever,
• the rear end of the rear arm having a second swivel pin pivotally connected to one end of a compressible elastic module having two ends, the other end of the elastic module being pivotably connected to a third swivel pin secured to the rear end of the rear portion of the sole,
• the three swivel pins forming a triangle when the elastic module is not compressed, and
• such that when the triangle formed by the three swivel pins is flattened, the three pins become substantially coplanar and the elastic module is compressed and wedged,
• the shoe further comprising a mobile intermediary sole and a linking module having a top end and a bottom end, the mobile intermediary sole being pivotally connected, to said second swivel pin and to a fourth swivel pin carried by the bottom end of the linking module, the top end being pivotally connected to the third swivel pin, the fourth swivel pin being positioned on said mobile intermediary sole such that the linking module is parallel to the front portion of the sole such that the first portion of the sole, the linking module, the mobile intermediary sole, and the rear arm form a parallelogram.