2005 Volume 1 Issue 1 Pages 33-36
The gold standard for assessing muscle size (cross-sectional area and volume) has been magnetic resonance imaging (MRI) and computerized tomography (CT), however, these processes are very expensive and generally require a medical facility, and in the case of CT, can involve exposure to high levels of radiation. The advent of B-mode ultrasound, in conjunction with simple anthropometric measures, such as circumference, can perhaps offer a quick, valid and reliable, and cost effective method to estimate muscle cross-sectional area (CSA) and track changes in muscle CSA following training. The purpose of this study was to document the reliability and accuracy of B-mode ultrasound in combination with anthropometry for assessing Kaatsu training induced changes in muscle-bone CSA. The data from thirty-three young men (mean age, 22.2 ± 5.1 yrs) in four different training groups were combined for the statistical analysis. All subjects were assessed prior to training and three days after the last training session. Anthropometric assessment of the right thigh circumference was taken at the mid point of the thigh (between the lateral condyle of the femur and greater trochanter), and midline anterior (QAT) and posterior (HAT) measures of subcutaneous adipose tissue thickness, at the same level as the circumference measures, was obtained with B-mode ultrasound. The muscle-bone CSA was estimated with the following equation: [π (r - (QAT + HAT) /2)2 ; r=circumference / 2π]. Each subject also had their right thigh imaged, at the same point as the circumference measure, by MRI. The estimated muscle-bone CSA was on average, 21% higher than the MRI measured CSA prior to training but the two methods were significantly (p<0.01) correlated (r=0.81). The correlation between the changes in estimated and MRI measured CSA due to muscle hypertrophy following Kaatsu training was also high (r=0.86) and significant (p<0.01) and only differed on average by 1.8% between two methods. In conclusion, it appears that anthropometry in combination with ultrasound can provide a reliable, accurate, and cost effective alternative method for assessing muscle hypertrophy.