Skinfold (SKF) Measurements and Bioelectrical Impedance Analysis (BIA)

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Skinfold (SKF) Measurements andBioelectrical
Impedance Analysis (BIA)

• John MacKenzie

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Skinfold and BIA Testing

• A SKF and BIA tests predict an individuals body
  density (Db) and also percent body fat using
  prediction equations

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Body Fat

• Knowing information about your body fat is
  crucial because of its effect on the body.
• Health risks (too much or too little)
• Required for physiological functions
• Phospholipids
• Insulation
• Transport and storage

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Field Testing

• SKF and BIA tests are both examples field tests
• Efficient for groups
• Inexpensive
• Not very complicated (especially SKF)

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• Must understand the principles and potential
  sources of error in the test, and above all else
  you must practice in order to effectively perform
  field tests

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Skinfold Testing

• Indirectly measures thickness of subcutaneous fat
  tissue using skinfold calipers of an individual
• Uses fold measurements from a number of sites on
  the body to determine body density and percent
  body fat through prediction equations

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Skinfold Calipers

• Calipers are the tools used for taking SKF
  measurements
• When deciding on a caliper to use, you should
  look at the cost, durability, accuracy, and
  precision

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Different Skinfold Methods

• The number of sites measured in the SKF test
  depends on which method you are using
• Most popular is the Jackson and Pollock
  sum-of-three method which has 3 different sites
  for each sex
• There are more accurate methods, but this one is
  more practical for larger groups

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• Research has demonstrated that using the 12-site
  method has had results similar to that obtained
  from Magnetic Resonance Imaging tests (MRI)

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Sources of Error in Skinfold Measurements

• Differences between SKF technicians
• Procedures/inter-tester variability in technique
• Variance/confusion about location and direction
  of folds
• Behnke Wilmore (1974) vs. Jackson Pollock
  (1978)
• Lack of measurements taken at each site
• Should be at least 2 measurements at each site

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Sources of Error Contd

• Hydration level/compressibility of the tissue can
  be a limitation
• Edema (extracellular water/fluid)
• Also important to know it is not recommended to
  take SKF measurements immediately after exercise

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Main Limitation

• SKF testing is very invasive
• Awkward/embarrassing situations between you and
  your client
• This can be even more prominent if you attempt
  SKF measurements on extremely obese clients