The subject should be standing upright with weight evenly distributed on both feet, the right arm relaxed and the right palm facing forward.
1. Mark the spot.
Mark the spot on the front midline of the upper arm over the biceps muscle, 1 cm above the level used to mark the triceps site.
2. Pinch the skin. Using your thumb and index finger, grasp a fold approximately 2 cm above the mark. Make sure that the skinfold goes down along the arm.
3. Position the caliper: Ensure that the mark remains centered between the caliper tips and that the jaws sit perpendicular to the length of the skinfold.
General rules: taking skinfold measurements.