MEASUREMENT AND EVALUATION OF HUMAN PERFORMANCE

Measurement and Evaluation of Human Performance

Measurement and Evaluation of Human Performance

Introduction

Obesity is a rising epidemic, as 1 in 3 adults in the United Kingdom are obese. This situation creates a major health problem because of obesity's deleterious association with many diseases such as hypertension, diabetes mellitus, coronary heart disease, and cancer. Because physical inactivity is a contributing factor in obesity, physicians should encourage patients to incorporate physical fitness into their lifestyle. Having an accurate, simple, and cost-effective tool to measure physical fitness is important, in light of the fact that a patient's self-report of fitness level is a poor indicator of actual fitness. One such simple measurement of physical fitness is the patient's body mass index. However, body mass index predicted fitness level less accurately than the measurement of percentage body fat. This suggests that incorporating an objective measurement, such as body fat composition, into the physical examination may be advantageous. (Ulijaszek and Kerr 2009 165-177)

Accurately estimating percentage body fat can be made indirectly by numerous techniques, including skinfold measurements, bioelectrical impedance analysis (BIA), underwater weighing, air displacement plethysmography, isotope dilution, potassium-40 counting, dual-energy x-ray absorptiometry, ultrasonography, and magnetic resonance spectroscopy. However, most of these techniques are labor intensive and out of reach for a majority of physicians. Skinfold measurement is most popular because of the method's low cost and practicality. The technique involves measuring skinfold fat at specific anatomical sites and using these values in a regression equation to predict the subject's percentage of body fat. (Hayes and Smith 2008 303-309)

The reliability of such a technique must be considered when interpreting the results from these types of evaluations, and many researchers and clinicians have questioned the results of bodycomposition assessments performed using skinfold fat measurements. However, in support of such measurements, studies have shown intraobserver reliability to be high, ranging from 0.94 to 0.99 for repeated measurements by the same individual. Interobserver variability also ranged from 0.92 to 0.99 for repeated measurements made by different observers. (Ostojic 2006 442-446)

In addition to reliability, the validity of the technique must be considered when interpreting results of evaluations. With respect to validity, the correlation coefficient between skinfold measurement and BIA, a well-established and valid measure of body composition, was observed to range between 0.84 and 0.92. (Kitano and Futatsuka 2001 122-125)

Although good reliability and validity have been established for skinfold measurement analysis using mixed-sex populations, it has not been sufficiently determined if sex differences will affect reliability and validity equally when men are compared against women. It can be hypothesized that differences would occur because the compressibility of fat differs between men and women, with the trend for women to be slightly less compressible than men. Therefore, the purpose of this study was to determine if sex differences in skinfold measurement will be apparent in intraobserver and interobserver reliability, as well as validity when compared with BIA measurements. (Himes and Siervogel 2009 1734-1740)

Methods

Subjects

This study was conducted with 71 male and 45 female first year chiropractic ...