Kinesiology is the study of human body movement. It helps physical educators and physicians understand and correct physical deformities, and enables coaches to provide effective training. Kinesiologists examine how the body moves and can function better, working in settings like sports and research. Key concepts include flexion, extension, and other motions; planes of movement like sagittal and frontal; and axes like vertical and sagittal that describe motion. Understanding these concepts is important for describing movements in different sports.