A unique biomechanical balancing and exercising device for rehabilitating body muscles, tendons, ligaments and joints in the ankles, legs, knees, and back in order to strengthen these areas to prevent injury. The balancing and exercising device comprises a rectangular shaped platform with a central opening therethrough to accommodate a semi flexible ball member. The platform utilizes a semi flexible ball member so that the individual has the ability to balance in numerous directions and have the angle of drop much steeper. A pair of ball-shaped rigid members are mounted on the platform and located adjacent to and on opposite sides of the central opening for balancing on and securing the semi flexible ball member therebetween. The platform is placed on top of the semi flexible ball member such that the central opening accommodates a top portion of the semi flexible ball member, and thereby allows the platform to be independently tilted or pivoted front-to-back up to a 25.degree. angle and vice versa and side-to-side approximately up to a 50.degree. angle.