The subject should be standing with weight evenly distributed on both feet, the shoulders relaxed, and the arms hanging loosely at the sides.
1. Mark the spot.
Palpate for the triangle portion at the bottom of the right shoulder blade. Using the cosmetic pencil, mark a cross on this spot. Make the first line at 45 degrees to the spine and cross this with a perpendicular line.
Note: If you cannot find the site, it may help to gently bring the arm behind the back, causing the shoulder blade to stand out. Then have the person relax the arm, re-examine the site, and make the mark when the skin is not stretched.
2. Pinch the skin. Place your index finger above and to the left of the mark, roughly 2.0 cm from it. Grasp a diagonal fold with your thumb and index finger.
3. Position the caliper: Set the top jaw of the caliper on the “+” mark.
General rules: taking skinfold measurements.