Muscle imbalance describes the situation in which some muscles become inhibited and weak, which others become tight, losing their extensibility. Muscle imbalance develops mainly between tightness and inhibition. Although muscle imbalance involves the whole body, the imbalance is more evident or starts to develop gradually and predictably in the pelvic region, where we speak about the pelvic or distal crossed syndrome, and the shoulder girdle. neck region, associated with a proximal or shoulder girdle crossed syndrome. Evaluation of muscle imbalance in a patient can be from location of the line of gravity in relation to the trunk.