Locomotion is the voluntary movement of an individual from one place to another. Walking, running, climbing, swimming are the examples of locomotion. All locomotion are movement but all movements are not locomotion. Macrophages and leucocytes in blood exhibit amoeboid movements. Animals and plants exhibit a wide range of movements. Such voluntary movements are called locomotion. Walking, running, climbing, flying, and swimming are all forms of locomotory movement. Locomotory structures need not be different from those affecting other types of movements. Methods of locomotion performed by animals vary with their habitats and the demand of the situation. Locomotion is required for a variety of reasons such as finding food, shelter, mate, suitable breeding grounds, favourable climatic conditions or to escape from predators. The chapter briefs about the different structures used for locomotion, their mechanism, the skeletal system, joints, the various disorders of the skeletal system, and the muscular system.