QUANTIFICATION OF DIAPHRAGM AND INTERCOSTAL MUSCLE THICKNESS AMONG OLDER ADULTS USING ULTRASOUND IMAGING. A RELIABILITY STUDY

Abstract

Measurement of respiratory muscle thickness is clinically important in the assessment of respiratory function. The present study was performed to establish the intra-class correlation coefficient (ICC) of measuring the diaphragm and intercostal muscles thickness using ultrasound images. Diaphragm and intercostal muscles images were captured using a 7-10 MHz transducer head at the end of quiet inspiration and expiration among 64 community- dwelling older adults. The mean± standard deviation (cm) of diaphragm and intercostal muscles thickness during quiet inspiration and expiration were 0.29±0.06; 0.21±0.05 and 0.54±0.11; 0.62±0.13 respectively. The present study using average measures of muscle thickness (two-way mixed model) of three images and the means of five points along the muscle fibers demonstrated moderate to excellent reliability (ICC, 0.63-0.98). The five-point method using the mean values of three measurements may be recommended for assessment in the clinical and research settings.