The arm, and its surrounding bones, form one of the most exquisite feats of engineering known. The complex articulations in the hand, elbow, and shoulder are to be marvelled at, for they allow a wide range of movement, from large, sweeping motions to minute manipulations. The structure of the arm is made primarily of the |humerus| (upper arm), the |radius| and the |ulna| (together forming the lower arm). The |humerus| articulates with the |scapula| to form the shoulder, while the |radius| and |ulna| articulate with the |carpal bones| of the wrist. With the hand, the versatile arm is well-suited to the varied manipulations and motions which are required in the ballet dancer, the watchmaker, and the boxer.
