NOVELTY - The pivoting mechanism has a cable mechanism transferring power from remotely located motor to the actual rotation axis. The cable mechanism includes a small pulley (130) affixed to a torque sensor (120), and cables (160) which are affixed to the small pulley and connected to a big pulley (150). A shoe holder (200) is mounted on the big pulley. The toe clip of the shoe holder can tighten the shoe with different size, and a side clip (230) prevents the shoe from sliding laterally.    USE - Pivoting mechanism for applying perturbations in tibial rotation, making subject to fight perturbations during major sagittal plane movement and improve their neuromuscular control in the off-axis control to reduce risk of lower limb injuries, such as anterior cruciate ligament.    ADVANTAGE - Human subject can easily get used to the elliptical movement with rotational pivoting perturbations at both feet and perform the pivoting elliptical movement naturally. Rotational perturbations result in stronger muscle activities in the targeted lower limb muscles. Hamstrings and gastrocnemius activities are increased considerably during forward elliptical movement with the perturbation. Improves sensory-motor performance through the pivoting elliptical training.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for the following:    (1) an exercising method in which a pivoting mechanism applies perturbations in tibial rotation;    (2) a sliding mechanism which applies perturbations in mediolateral sliding or makes the footplate free to slide mediolaterally;    (3) a rotating mechanism which applies perturbations in inversion/eversion and/or in dorsiflexion/plantar flexion or makes the footplate free to rotate;    (4) a knee training mechanism;    (5) a pivoting elliptical machine;    (6) a pivoting stair climber; and    (7) a knee training protocol.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a pivoting mechanism with controlled tibial rotation, which can be combined with sagittal movement using various exercise machines.    Torque sensor (120)    Small pulley (130)    Big pulley (150)    Cables (160)    Shoe holder (200)    Side clip (230)