Steps to Perform The Skinfold Method
1. All measurements should be taken on the right side of the body
2. Meticulously identify the site to be measure with the thumb and forefinger of the left hand( the more subcutaneous fat a client has, the further apart your thumb and forefinger will need to be to grasp an adequate fatfold). Your left elbow should e angled up.
4. The grasp should be one centimeter (1/2 inch) above the site where the calipers will be placed to ensure that pressure from the fingers does not affect the measurement.
5. To be certain that only skin and fat has been grasped, you may, at some site, ask your client to contract the underlying muscle while you continue holding the skinfold with your left hand. If you have inadvertently pinched muscle as well as fat, the muscle tissue will separate from the rest of the skinfold as the contracts.
6. Holding the calipers in your right hand, take the measurement one centimeter (1/2 inch) below your left thumb and forefinger. The calipers should be held level and perpendicular to the direction of the skinfold. Release the jaws of the calipers completely (still holding the skinfold with your left hand) for no more than four seconds while you obtain the reading. (If the calipers remain pinching the skinfold for longer than four seconds, intracellular fluids will be forced out of the tissues and result in an inaccurate, lower value.)
7. A minimum of two measurements should be taken at each site. If your measurements vary by more than two millimeters, take a third or fourth measurement until you have obtained two measurements which vary by less than two millimeters. It is recommended that the measurements be taken in rotational order (e.g., triceps, sprailiac, thigh, then back to triceps, suprailiac, thigh), in order to avoid repeatedly compressing the tissues at the same consecutive site, resulting in smaller and smaller values.
Standardized site for women:
Triceps – A vertical fold measured in the midline of the posterior arm over the tricep muscle. Anatomical landmarks are the lateral projection of the acromial process and the inferior border of the olecranon process with the elbow flexed at a 90 degree angle. A tape measure should be stretched between these two landmarks and the midpoint located on the lateral aspect of the arm. The actual site is at this level, only on the posterior aspect. During measurement, the right elbow should be extended and relaxed.
Suprailiac – a 45 degree angle diagonal fold immediately above the iliac crest along the anterior axillary line (this is different from the site used in the Durnin & Womersley protocol).
Thigh- a vertical fold in the midline of the anterior aspect of the thigh, midway between the inguinal crease (fold in the hip during hip flexion), and the proximal border of the patella. The body weight should be placed on the left leg so the right thigh is relaxed.
Standardized site for men:
Chest (pectoral) – a diagonal fold taken one half the distance between the anterior axillary line(underarm crease) and the nipple.
Abdomen—a vertical fold taken at the distance of two centimeters (one inch) to the right of the umbilicus. (This fold is horizontal in some other protocols.)
Thigh-same as for females
Calculating estimated percentage body fat:
1. Carefully measure the appropriate sites two to three times each, following the directions outlined above.
2. Find the average value for each site and then add all the sites together.
3. Use the norms chart.