Measurement Tools — Skinfold Measurements
What It Is
Measurements of folds of skin and fat are taken from several specific locations or sites on the body and then entered into an equation to estimate total body fat.
How It's Done
- Measurements are taken at different sites on the right side of the body while the person stands straight but relaxed.
- The most popular site is the triceps (located on the back of the upper arm. Other sites include the biceps (front of the upper arm), subscapula (just below the tip of the right scapula), iliac crest (vertical fold above the hip bone), abdomen (one inch to the right of the belly button), thigh, and chest.
- A pinch of skin is grasped between the thumb and forefinger and it is pulled away from the underlying muscle.
- The width of the skin fold is measured in millimeters with a specially calibrated caliper.
- Each measurement is usually taken three times and then the average of the three measurements is recorded.
- The measurements from each site are entered into an equation, and body fat is calculated.
- The calipers are not overly expensive.
- It does not require sophisticated equipment.
- It's portable.
- It's fast.
- This procedure relies on an assumption that may or may not be true: the fat under the skin is proportional to the total body fat.
- The equations were developed based on normal weight people. Applying them to people with excess fat may be inaccurate.
- Some measurements cannot be done without the help of another person.
- The amount of tissue picked up to form the skinfold can vary.
- You get different results depending on how hard you pinch the fold of skin. More expensive calipers are more accurate.
- If a different person takes the measurements each time, they may not be accurate or consistent.
- Proper technique requires training. Even under the best of circumstances, individual differences in measurement techniques are common.