The studies of human body motion have been motivated by a large number of application domains: visual surveillance,clinical analysis, computer animation, athletic performance

analysis, robotics, and biometrics. Moreover, human motion analysis has many challenging issues, because the highly flexible structure and self-occlusion of the human body mandates complicated processes for the segmentation and

analysis of motion:The motion of the human

body may be defined by the movement of various body parts such as hand or limb segments. The human body consists of

several rigid parts connected by the joints, but the motion of a full human-body is non-rigid and articulated . Human gait (walking and running) is known to be one of the most universal and complex of all human activities.