Define Skirt Fold Thickness (SPT) Method?
Skin fold measurement is the most widely used field method of body composition assessment. The skin fold (SKF) is an indirect measure of the thickness of subcutaneous adipose tissue at a specified site. Most SKF equations use two or more SKF measurements to predict either body density (Db) or BF%. This method assumes that the thickness of the subcutaneous adipose tissue is proportional to the total amount of fat throughout the body. Equations for predicting fat mass from skin folds have been developed.
A set of callipers is used to measure the skin folds at various sites on the body, most Commonly triceps, biceps, sub scapular and suprailiac. The 4 sites are summed and using logarithms, there is a linear relationship with total body density, age and gender specific. There are reference levels based on Durnin and Wormesley (1974) equations. These equations correlated well with the levels measured with under water weighing. The accuracy and precision of SKF measurements is highly dependent on technician skill and type of SKF calliper. One needs to spend a lot of time and practice hard to develop skill as a SKF technician, and standardized procedures must be carefully followed.
SFT is an easy, quick, widely used and precise method. Thus, it is possibly the most useful measure of BF% in field. This is a convenient and only moderately invasive method of measuring BF%. Callipers are easily available. One limitation is that the assessor needs to be experienced, as the exact location of the skin fold measurement needs to be consistent. The obese population represents limitations for skin fold measurements. Skin fold callipers cannot open wide enough to measure the total fat thickness, thus tends to grossly under estimate body fat percentage in the obese population.