An isometricexercise refers to any physical activity involving static muscle contractions. The term “isometric” is derived from the Greek roots “isos” (equal) and “metron” (measure), which means that during isometric exercise, muscle length is broadly unchanged and consequently joint angle remains the same. From a biomechanical point of view, this exercise modality means that the net moment generated by the individual at the joint level is equal to the resistant moment applied to the body segment in an opposing direction. Actually, muscles slightly shorten and involve a stretch at the tendon level but the length of the muscle-tendon complex remains constant. Depending on the amount of resistance applied to the body segment, the level of muscle contraction can be maximal or submaximal. Performing the “wall sit/phantom chair” exercise,...