Assessing muscle architecture: validity and reliability of portable device for conducting multi-center studies using...

Ultrasound is frequently used to assess muscle mass adaptations in athletes, with measurements often collected across multiple training centers. Extended field of view (EFOV) technology provides a faster, safer, more accessible, and less expensive alternative to gold standard methods such as magnetic resonance imaging (MRI). However, the reliability and validity of portable ultrasound devices for EFOV imaging are not well established. This study aimed to: a) evaluate the validity of a portable ultrasound device compared to a commonly used clinical device, and b) assess the reliability of EFOV ultrasound measurements using both a validated clinical device and a portable device.

Twenty-four recreational athletes participated. EFOV images of the rectus femoris and vastus lateralis muscles were captured using both a clinical and portable device, and cross-sectional area (CSA) was measured at three regions of interest (ROIs).

A strong correlation (r=0.989-0.999, p<0.001) between the two devices across all ROIs was found, with minimal mean differences. Both devices demonstrated high reliability, with low coefficients of variation (clinical=2.22%, portable=3.55%).

The portable device is a valid and reliable tool for EFOV ultrasound measurements, facilitating its use in multi-center studies by allowing comparison across different devices and training centers.