Durnin and Rahaman developed equations for converting skinfold thickness measurements to percent body fat for young adults and children.
Populations studied:
(1) both females and males
(2) adolescents 12-16 years of age
(3) young adults 18-34 years of age
Taking skinfold thickness measurement:
(1) Use skinfold calipers (Harpenden calipers used by authors)
(2) The skinfold is pinched up firmly between the thumb and forefinger and pulled slightly away from the underlying tissue before applying the calipers.
(3) Values read in millimeters
Locations where skinfold thickness measurements taken:
(1) biceps: over the mid-point of the muscle belly with the arm resting supinated on the person's thigh
(2) triceps: over the mid-point of the muscle belly mod-way between the olecranon and the tip of the acromion, with the upper arm hanging vertically
(3) subscapular: just below the tip of the inferior angle of the scapula, at an angle of 45° to the vertical
(4) suprailiac: just above the iliac crest in the mid-axillary line
sum of the 4 skinfold thicknesses in mm =
= SUM(4 measurements in mm)
logarithm of sum for the skinfold thicknesses =
= LOG10(sum of the 4 skinfold thicknesses)
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Group
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Equation for Density
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Standard Error
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boys
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= 1.1533 - (0.0643 * (LOG10(sum skinfolds)))
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+/- 0.0083
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girls
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= 1.1369 - (0.0598 * (LOG10(sum skinfolds)))
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+/- 0.0081
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men
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= 1.1610 - (0.0632 * (LOG10(sum skinfolds)))
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+/- 0.0069
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women
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= 1.1581 - (0.0720 * (LOG10(sum skinfolds)))
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+/- 0.0096
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Siri Equation
percent body fat =
= (((4.95 / (body density)) - 4.5) * 100
