THE TECHNICAL ERROR OF MEASUREMENT FOR SELECTED SKINFOLD AND CIRCUMFERENCE MEASUREMENTS

Abstract

1569 We have reported previously on developing the skill to obtain valid skinfold and circumference measurements (Heaney et al., Med. Sci. Sports Exerc. S1, 1990). This abstract addresses the issue of the number of practice trials necessary to perform consistent and precise skinfold and circumference measurements. The Technical Error of Measurement (TEM), derived from the square root of the mean square error, can be used to evaluate the progress of acquiring a reliable measurement technique for anthropometrists. The reliability in learning skinfold and circumference measurement technique was evaluated in 22 novice testers. Each tester completed a series of three trials per site before measuring a different person until 120 triceps skinfold measurements and 75 waist circumstance measurements were completed. A TEM value was determined for each novice tester at each measurement site upon completing eight sets of 15 skinfold trials and five sets of 15 circumference trials. A criterion value was established for each triceps skinfold and waist circumference by an experienced anthropometrist. The table below displays the TEM results. Reliability significantly improved for both the triceps skinfold and the waist circumference. Upon completing 15 skinfold measurements, the TEM was 3.0914 mm, an 18% error from the criterion value compared with the TEM of 1.2758 mm which was 7.43% of the criterion value after completing 120 skinfold measurements. In contrast, the circumference TEM was 0.9493 cm or 1.15% of the criterion value after only 15 trials and 0.5643 cm or 0.7% of the criterion value after 75 trials. These results suggest that a suitably reliable circumference measurement technique can be acquired after completing a minimum of 15 practice trials. However, developing a reliable skinfold technique requires more than 120 practice trials.Table