US Patent 8732981 Eccentric toe-off cam lever

A sole system which allows plantarflexion and dorsiflexion in the running/walking gait; provides a mechanical advantage through articulation of the forefoot to stimulate an upward plantar moment force during toe-off; and increases the distance per step without altering the stride pattern. An embodiment of the current invention has an eccentric toe-off cam lever (“cam lever”) integrated into the midsole of a shoe. The cam lever of the embodiment includes: a distal longitudinally extending cam element; a forefoot fulcrum element; and a rear longitudinally extending cam element.