<P> The term anatomical variation is used to refer to a difference in anatomical structures that is not regarded as a disease . Many structures vary slightly between people, for example muscles that attach in slightly different places . For example, the presence or absence of the palmaris longus tendon . Anatomical variation is unlike congenital anomalies, which are considered a disorder . </P> <P> Joints, especially synovial joints allow the body a tremendous range of movements . Each movement at a synovial joint results from the contraction or relaxation of the muscles that are attached to the bones on either side of the articulation . The type of movement that can be produced at a synovial joint is determined by its structural type . </P> <P> Movement types are generally paired, with one being the opposite of the other . Body movements are always described in relation to the anatomical position of the body: upright stance, with upper limbs to the side of body and palms facing forward . </P> <P> Terms describing motion in general include: </P>

Latin terms for the position of body parts