appendicular locomotion

Appendicular locomotion refers to movement facilitated by limbs or appendages. In tetrapod vertebrates, this primarily involves the hind legs for propulsion, though forelegs are used in aquatic animals like penguins and sea turtles, which have evolved them into flipper-like structures. Invertebrate appendages are also known as legs.12

The appendicular skeleton connects the free extremities (arms or legs) to the body's axis. In humans, the pelvic girdle connects the legs to the vertebral column, while the pectoral girdle connects the arms. These structures have undergone significant evolutionary changes, leading to differences in function and range of motion between the upper and lower extremities.3

Some microorganisms, like amoebas, use pseudopodia for locomotion, which involves extending a part of the body that anchors and pulls the rest forward. This process involves a conversion of the cytoplasm between gel and sol states.4