The arms and hands of the subject can express body language, mood, attitude and action. The distance of the arm and hand, from shoulder top to the fingertips, is less than the length of the legs, which is half the total height of the body. Male arms are generally more bulky and muscular, while women’s are generally more slender with less muscle definition.
The upper arm is longer than the forearm. When the hand is brought up to the shoulder, it is noticeable that the upper arm is slightly less than the length of the forearm and hand, to the first row of knuckles. The tip of the elbow moves forward as the forearm is brought up. This is because the tip of the elbow is actually the end of the forearm bone, rather than the tip of the upper arm bone. The inside knob of the elbow, which is not visible from this view, is the tip of the upper bone. It changes position only when the upper arm is moved. When relaxed in a downward position, the arm is slightly bent at the elbow.
The form of the arm changes with its position. When the arm is brought up, the muscles are contracted, causing the inner muscles to have curvature and form. When the arm is straight, the top muscles are lengthened and flatten out.
Usually when the wrist is turned so the thumb is positioned away from the body, the elbow will be turned in toward the body. When the thumb is turned in toward the body, the elbow will be tilted out away from the body.
The subtle differences of form and shape are more noticeable with certain poses and views. For example, when the arm is flexed, the muscle form is more accentuated.
Arm build reflects the body type. A person with a slender form will have slender arms, just as a person with a more muscular form will have muscular arms