Accuracy of Skinfolds (Five Assumptions)

Measurement errors due to tester inaccuracy and poor site location sometimes lead to inaccurate skinfold results. In addition, five assumptions have traditionally been made when measuring skinfolds:

1. That the skinfold is constantly compressible;
2. That skin thickness is a constant proportion of the skinfold;
3. That inter-individual fat patterning is constant;
4. That fat represents a constant proportion of adipose tissue; and
5. That the proportion of subcutaneous fat to internal fat is constant.

• Two practical error sources: tester inaccuracy and poor site location.
• Five traditional assumptions:
  1. Skinfold is constantly compressible.
  2. Skin thickness is a constant proportion of the skinfold.
  3. Inter-individual fat patterning is constant.
  4. Fat is a constant proportion of adipose tissue.
  5. Subcutaneous-to-internal fat proportion is constant.

• skinfold-measurement — the method these assumptions underlie.
• body-composition — what skinfolds estimate.
• skinfold-assessment — states the current, quantified accuracy figure (~±3.5% with a skilled tester) these five assumptions collectively produce; tester skill and site consistency are still the dominant error sources today.