The body is incredibly complex. With over 200 bones, hundreds of muscles and just as many joints (as well as connective issue, nerves, organs and cells) it can be difficult to distill information about the body in a way that is easily digestible, and importantly, functional for students. One way we can do this is by breaking the systems of the body down into units of action. For example, when talking about several joints that work together for a common purpose we can refer to this is a ‘joint complex’ (e.g. the shoulder, or shoulder joint complex, comprises four joints).