Effects of Limb Dominance and Subcutaneous Fat Thickness on Muscle Echographic Intensity Measured With Sonography

Objective: Skeletal muscle echographic intensity (EI), with sonography, can estimate muscle quality, an important factor in exercise and musculoskeletal interventions. Data on how limb dominance and subcutaneous fat thickness (SCT) can affect EI in young women are needed. Therefore, the aim of this study was to determine whether limb dominance and SCT affect muscle EI in women, ages 18 to 35. Materials and Methods: The Waterloo Footedness and Handedness questionnaire was used to classify limb dominance in a cohort of 27 women. The biceps brachii, rectus femoris, and tibialis anterior were imaged using a Philips CX-50 and L12-3 linear transducer. Subcutaneous fat thickness and raw EI were averaged using ImageJ software. Subcutaneous fat thickness was accounted for with corrected EI measures. Paired t -tests compared dominant/nondominant limbs. Pearson correlations analyzed SCT and EI relationships. A Bonferroni correction was applied and the p-value set at .0042. Results: The corrected EI was significantly higher than raw EI for all muscle sites ( p < .0001). Subcutaneous fat thickness was negatively correlated with raw EI in right and left biceps brachii ( r = −.62, p = .0005; r = −.65, p = .0002) and rectus femoris ( r = −.68, p < .0001; r = −.66, p = .0002). Conclusion: This study indicates that SCT should be considered when estimating muscle quality.