The document discusses how animals move in three main ways. It describes how elephants move in a unusual gait similar to Groucho Marx, kicking their feet forward. It then explains the two main types of skeletons that provide structure and support for movement: exoskeletons which are external shells and endoskeletons which are internal frameworks of bone and cartilage. The human skeleton is described as a unique endoskeleton that allows for upright posture and flexible movement through joints between bones. Muscle contraction is also summarized, explaining how skeletal muscles interact with the skeleton through antagonistic pairs of muscles to produce movement.