How to measure skinfolds for fat mass assessment - Guide for Professionals

How to measure skinfolds for fat mass assessment – Guide for Professionals

The measurement of the skinfolds is important to determine body fat, especially for athletes. Find out all you need to know!

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The measurement of the skinfolds is used to estimate the percentage of body fat, mainly in athletes.

The sum of the values of certain skinfolds also allows the evaluation of the patient’s progress in terms of body composition, as a result of dietary and/or athletic interventions, and the comparison of the data with the rest of the population.

Those skinfolds are measured in specific parts of the body by using a skinfold caliper. For most of them, it is necessary to pre-mark the anthropometric reference sites with a dermatograph pencil.

If you want to learn more about measuring skinfolds, take a five-minute break to read this article and download the guide below!

Basic Principles

Before you start including skinfolds measurement in your appointments, it is essential to consider these aspects:

  • The subject should be standing, in a relaxed position and with the upper members totally relaxed along the torso (unless otherwise indicated);
  • The skinfolds should be measured on the right side of the body;
  • The tester should locate the skinfold sites with their left hand’s thumb and index finger (or the non-dominant hand);
  • The skinfold should be lifted 2cm above the place to be measured and the caliper should be positioned in the marked site, perpendicular to the skinfold orientation;
  • To measure the skinfold, the tester should pick up the minimum amount of tissue, making sure that there are only skin and subcutaneous tissue, and that underlying muscle tissue is not incorporated;
  • Both sides of the skin surfaces of the skinfold should be more or less parallel and the caliper should be held at a 90-degree angle to the marked site of the skinfold;
  • The skinfold measurement should be registered 2 seconds after the full pressure of the caliper is applied;
  • The measurements should be repeated 3 times in each location, and the average of these measurements should be considered.

Main Skinfolds

We present below some practical information to measure the main skinfolds. The measurement of these skinfolds is necessary for the use of absolute predictive equations, described further ahead.

Triceps Skinfold

The triceps skinfold site should be marked on the posterior surface of the arm, on the midline of the triceps muscle, halfway between the acromion and radius.

The skinfold should be picked up parallel to the long axis of the arm. The subject should be standing, with their arms relaxed along the torso. The tester should be behind the subject, on their right side.

Subscapular Skinfold

The subscapular skinfold site is marked immediately below the inferior angle of the scapula.

The location of the skinfold should be marked 2cm below the subscapular skinfold site (by using an anthropometric tape), laterally and obliquely.

The skinfold forms a line of about 45 degrees (but it follows the skin’s natural fold lines), extending obliquely in the direction of the right elbow.

Biceps Skinfold

The biceps skinfold should be marked in the anterior surface of the arm, over the biceps, and halfway between the acromion and radius.

The patient should be standing, with their arms relaxed along the torso. The skinfold should be picked up vertically (parallel to the length of the arm).

Supraspinale Skinfold

The supraspinale skinfold is located in the intersection between two lines: the line that connects the Iliospinale point to the axillary’s anterior margin, and the horizontal line marked on the Iliocristale point.

Iliospinale point: anterior superior iliac spine point.

Iliocristale point: the most lateral point of the upper margin of the iliac crest.

The subject should be standing with their arms relaxed along the torso. They can also cross the right upper arm over the torso. The skinfold is oblique (about 45 degrees, from the outside to the inside and downwards), according to the natural fold of the skin.

Abdominal Skinfold

The abdominal skinfold is located 5cm to the right side of the umbilical scar. This distance should be measured with an anthropometric tape.

This distance is used for individuals measuring around 170cm. When the individual’s height differs greatly from this value, it is necessary to adjust the distance by applying the following formula:

Distance of the point to the umbilical scar = 5 x (Height / 170cm)

The patient should be standing, with their arms relaxed along the torso. The abdominal skinfold is measured vertically at the umbilical point.

Front Thigh Skinfold

The point should be marked halfway between the inguinal fold and the upper point of the patella, in the midline of the leg’s anterior surface.

The subject should be seated on the edge of a bench with an upright torso and the right leg extended. The hands should be under the thigh and exert upward pressure to reduce the tension of the skin. The left leg should be flexed, forming a 90-degree angle between the thigh and the leg.

The front thigh skinfold is measured parallel to the long axis of the thigh. Since this fold can be harder to point out, the tester may ask for the assistance of a third person, who raises the fold with both hands at about 6cm on either side of the marked site.

Medial Calf Skinfold

The medial calf point should be marked in the internal surface of the leg, at the level of the maximum circumference of the calf. To mark this point, the subject should be standing, with their arms relaxed along the torso, with their feet apart and the bodyweight equally distributed between both feet.

The tester should be positioned in front of the patient and look for the maximum circumference using an anthropometric tape. This horizontal line should be intercepted by a vertical line located in the middle part of the leg.

The subject should place their right leg in an anthropometric box and ensure there is a 90-degree angle between the thigh and the leg. The fold should be measured in the medial calf skinfold site, vertical to the length of the leg.

Iliac Crest/Suprailiac Skinfold

The iliac crest skinfold should be raised superior to the iliocristale, at the level of the line that connects the midpoint of the armpit to the ilium.

The skinfold is measured immediately above the iliac crest skinfold site. To do so, the tester should place the thumb over the iliac crest point and then measure the fold (it is taken near horizontally, but it follows the natural fold lines of the skin).

Would you like to have these recommendations available during your appointments?

Our team has combined them in a guide, which you can download for free by clicking below:

How to Determine the Body Mass Using the Skinfolds’ Measurement?

Although you can determine the body mass of your clients using a body composition scale, such as this oneit is also possible to deduce it by using the measurement of certain skinfolds, based on predictive formulas.

For the body mass to be correctly determined from the measurement of the skinfolds, it is necessary to calculate it using predictive equations, such as the ones listed below:

Evans Formula (2005)

This equation is suitable to estimate the percentage of body fat in athletes. It depends on gender, origin, and the abdominal, triceps, and front thigh skinfolds.

Slaughter Formula (1988)

This equation directly determines the percentage of body fat in children and teenagers (7-18 years old). It depends on the level of maturity, origin, and the triceps and subscapular skinfolds.

Peterson Formula (2003) (four-compartment model):

It determines the percentage of body fat in adults (18-55 years old). It depends on the current weight, age, height, and the triceps, subscapular, supraspinale, and front thigh skinfolds.

How can Nutrium help you?

Nutrium allows you to consolidate all the information and appointments of a patient in one place. If you use the body mass determined by a bioimpedance scale or by predictive equations, Nutrium will be useful.

In the first case, please note that by using an InBody bioelectrical impedance scale, you can automatically import all the measurements with one clickRead this article to learn more.

If you prefer to determine the body mass by using predictive equations, simply register the necessary skinfold measurement. Nutrium will automatically do the math. Here’s how to proceed:

1. In the Measurements tab, register the skinfold.

If the skinfolds do not show up in that tab, just click on the green button at the bottom of the page Configure measurement types.

2. After registering the necessary skinfolds, depending on the age and the level of physical activity of the subject, the software will automatically calculate the percentage of body mass, using one of those equations.

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