Skinfold Measurements and Girth

Skinfold Measurements• Target Population:

– Suitable for all populations, difficult to get reliable measurements with individuals who are obese

• Validity: – + or – 3.5% – Can be used as a monitoring device to indicate

changes in body composition over time

• Reliability: – Can vary from tester to tester depending on their

skill and experience

• Advantages:– Widely utilized to assess body composition

Description of Skinfold Measurement

• Estimation of body fat by skinfold thickness

• Measurements can range from 3 to 9 different standard anatomical sites around the body

• Triceps

• Biceps

• Chest

• Midaxilla

• Subscapular

• Abdomen

• Suprailium

• Thigh

• Calf

Equipment Required

• Flexible Tape Measure

• Skinfold Calipers

Sanitization• Body Composition measurements

require contact with the skin!

• Professional Personal Trainers must take the necessary precautions to limit the spread of bacteria and/or viruses.

YOU MUST SANITIZE EVERYTHING THAT COMES IN CONTACT WITH A

CLIENT!

Sanitization

• HAND WASHING IS THE MOST EFFECTIVE MEANS OF PREVENTING THE SPREAD OF INFECTION

• Hand Washing Should Be Done:–Before and after client contact!

Sanitization• Wash hands, utilize gloves,

antibacterial gel and/or disposable wipes before, during and after body composition measurements.

• Clean and sanitize all equipment. This includes calipers and tape measures.–This also applies to stethoscopes

utilized in blood pressure measurements

Procedures• Skinfold measurements should be made

on dry skin, prior to exercise• The calipers are calibrated with a specific

jaw pressure, abuse of the calipers can leave them useless due to inaccuracy

• Fat compresses, thus it is essential that you rotate through measurement sites which allows time for skin to regain normal thickness

• It takes experience before sufficient accuracy of measurements occurs

Procedures

1. All measurements should be made on the right side of the body (for consistency)

2. Grasp the skin firmly with the thumb and index finger to form a fold of skin and subcutaneous fat

3. Place the caliper perpendicular to the fold .5 to 1 inch away from the thumb and index finger

4. Release the caliper grip

5. Pinch should be maintained with thumb and index finger while reading the caliper

Procedures

6. Wait 1 to 2 seconds (not longer) before reading caliper

7. Read the dial on the caliper to the nearest 0.5 mm

8. Obtain one measurement from each site, and repeat all test sites for a second trial

Procedures9. If the two measurements are within 1 to

2 mm take the average of the two

10. If the two measurements are not within

1 to 2 mm take two more additional

measurements and average the

two (rotate through the sites)

TricepsTriceps:• Use a tape measure • Arm held freely to the side of

the body• Measure halfway between the

acromion (shoulder) and olecranon processes (elbow)

• Grasp a vertical fold of skin on the posterior surface of the arm (over the triceps muscle)

• If you are unsure if you have pinched only skin and no underlying muscle tissue, ask the subject to flex the muscle while you pinch.

Biceps• Use a tape measure • Arm held freely to the side of

the body with the palm supinated

• Measure halfway between the acromion (shoulder) and radius

• Take a vertical fold of skin on the anterior surface of the arm (over the biceps muscle)

• If you are unsure if you have pinched only skin and no underlying muscle tissue, ask the subject to flex the muscle while you pinch.

Chest:

• Measure mid-way between the anterior axillary fold (underarm) and nipple

• Take a diagonal fold, with the long axis of the caliper directed towards the nipple of the chest

Midaxilla:

• Measure from the midaxilla (middle of armpit) at the level of the xiphoid process of the sternum

• Take a vertical fold

Subscapula:• A diagonal fold taken at a 45

degree angle; 1 to 2 cm below the inferior angle of the scapula (bottom point of the scapula)

• If there is difficulty finding this landmark, get the subject to reach behind their back with their right arm, while feeling for the movement of the scapula

• On females it is sometimes difficult to take this measure and maintain modesty, and also the bra-strap may often obstruct this site.

Abdomen:

• Measure 1 inch to the right of the umbilicus (belly button)

• Take a vertical fold

• Do not place the caliper or fingers inside the navel

Suprailium:

• Measure from the axilla (armpit) to above the crest of the ilium

• Take a diagonal fold at a 45 degree angle above the crest of the ilium

Thigh:

• Measure the mid-point of the anterior (front) surface of the thigh, midway between the hip and knee joints

• Take a vertical fold 

• Stand with the weight on the back foot

Calf:

• Take a vertical fold at the maximum circumference of the calf on the midline of its medial border

• The subject should place their foot on a chair or box so that the knee is at approximately 90 degrees

Results• There are hundreds of equations available for

converting skinfold measurements to a percent body fat

• It is best to use a formula that is based on a population sample that most closely resembles the person who is measured

• You can use the sum of several sites to monitor and compare body fat measures

• Go to

http://www.linear-software.com/online.html

to find out your body fat percentage

Table of general guidelines for using total sum (in millimeters) of the seven skinfold sites: triceps, biceps, subscapula, suprailium, abdomen, thigh, calf

Excellent Good Average Below Average

Poor

Typical Male 60-80 81-90 91-110 111-150

150 +

Female 70-90 91-100 121-150

101-130

150 +

Athletic Male 40-60 61-80 81-100 101-130

130 +

Female 50-70 71-85 86-110 111-130

130 +

Durnin-Womersley Formula• Biceps, Triceps, Subscapula, and Suprailium

• Add the totals of the four sites and then find the gender and age categories for the body composition in the table provided or go to

http://www.linear-software.com/online.html

to find out your body fat percentage

Body Fat Percentage Ranges by The American Council on Exercise

   Classification Women (% fat) Men (% fat)

Essential Fat 10-12% 2-4%

Athletes 14-20% 6-13%

Fitness 21-24% 14-17%

Acceptable 25-31% 18-25%

Obese 32% plus 25% plus

Circumference

• When measuring, you need to make sure the tape is not too tight or too loose, is lying flat on the skin, and with the tape horizontal

Circumference• Neck:

– Across the Adam’s apple

• Forearm:– The subject holds the arm out with the palm

supinated – Maximum girth of forearm

Circumference Measurements• Biceps Relaxed:

– Measure at the maximal circumference of the biceps, measure with the palm supinated

• Biceps Contracted:– Arm is out to the side at a 90 degree angle and

elbow is flexed– Fist clenched; maximally contract biceps– Largest circumference is measured

Circumference• Upper Chest:

– Taken at the level of the middle of the sternum with the tape passing under the arms

– Measurement taken at the end of a normal expiration

• Lower Chest:– Across the nipple line

Circumference• Abdomen:

– Level of umbilicus (belly button)

• Waist: – Narrowest part of waist below the rib cage and just

above the top of the hipbones.

Circumference

• Hips:– With feet together, measure circumference at the

widest portion of the buttocks• Thighs:

– Measure 10 inches above the top of the patella (maximal girth of thigh below gluteal fold)

• Calf:– The subject stands erect with their weight evenly

distributed on both feet and legs slightly apart– Measure at the maximal circumference between the

ankle and the knee