There is an unfilled, long felt need in the art for a dual leg system for enhancing proprioception, balance, and coordination with flexibility for providing a wide range of exercises with a reduced set of equipment so as to lower costs and optimize storage room in crowded facilities. The present invention provides a novel solution to fill this long felt need.
Representative publications in the prior art addressing this area include the following:    U.S. Pat. No. 4,767,118, issued Aug. 30, 1988, discloses securing a foot to movement resisting member with rail mounted receiving channel in bottom of sole-piece.    U.S. Pat. No. 5,317,822, issued Jun. 7, 1994, discloses a footplate sole with interchangeable appliances secured through peripheral rail in slots, the rail in the bottom receiving different members.    International Publication No. WO 2006094397, published Sep. 14, 2006, discloses an apparatus for exercising foot/ankle muscles with a fore-foot component attached to resistance components and telescoping members.    U.S. Pat. No. 4,605,220, issued Aug. 12, 1986, discloses an ankle exerciser and rehabilitation device with the foot plate attached to support post by a telescoping adjustable universal joint.    U.S. Pat. No. 7,254,905, issued Aug. 14, 2007, discloses a longitudinal guiding portion extending longitudinally along length soleplate for longitudinal rail with T-sectioned channels.    U.S. Pat. No. 4,328,627, issued May 11, 1982, discloses metal mounting beam embedded insole with series of apertures to which attachments may be fixed to the channel in the bottom.    US Patent Publication No. 2008/0269026, published Oct. 30, 2008, discloses a base housing and footrest cover around actuating system, all configured to define axis of rotation of pivotal rocking motion with an adjustable footrest displacement.    U.S. Pat. No. 4,653,748, issued Mar. 31, 1987, discloses an exerciser with a flat platform to support standing user on a hemispherical member for tilting around re-locatable axis points.    U.S. Pat. No. 5,891,002, issued Apr. 6, 1999, discloses an exerciser for rehabilitation of the ankle after medical complications, with single and dual foot modes.    UK Patent No. GB 1372342, issued Oct. 30, 1974, discloses an ankle exercising apparatus universally tiltable platforms with control coil spring and pivot.    U.S. Pat. No. 3,834,723, issued Sep. 10, 1974, discloses attachments secured by permanent magnets.    U.S. Pat. No. 7,322,914, issued Jan. 29, 2008, discloses an ankle exercise device for rehabilitating injury with pivot assembly members connected to frames and tension members extending between frame and square, having a telescoping adjustable body contact part.    U.S. Pat. No. 7,775,952, issued Aug. 17, 2010, discloses a balance training apparatus sub-frame with a framed-in area of square-frame construction.    U.S. Pat. No. 5,518,476, issued May 21, 1996, discloses an ankle exercise device for exercising subtalar complex with controlled triplaner motion on a square, telescoping standing platform and handrail for a rotatable foot plate that is controllable and adjustable in three planes with fixed settings in all planes, including oblique.    U.S. Pat. No. 7,621,861, Nov. 24, 2009, discloses a rotational exercise apparatus with foot plates mounted on platform for rotating and counter rotating platform and plates constructed of square tubing.