Gait analysis is the systematic study of animal limb movement, or more accurately, the study of human walking movement in general. The study utilizes the eyes and brain of the observer and uses instruments to assist in measuring body movement, body mechanics, and muscle activity. Gait analysis is used to assess, plan, and treat an individual's ability to walk. It is also often used in sports biomechanics to help athletes run more efficiently and to identify medical issues related to whether an injury is posture-related or movement-related.