The aim of this study was to examine elbow flexion torque, muscle cross-sectional area (CSA), and leverage in boys and girls. Thirty-eight prepubertal children (9.6 ± 0.3 years) volunteered to participate. All performed isometric flexion actions at 10°, 50°, and 90° of elbow flexion. Magnetic resonance imaging was used to assess elbow flexor (EF) muscle CSA and brachialis moment arm lengths. No significant gender differences were observed for any of the variables studied. EF CSA was directly proportional to isometric torque at 50° and 90°. CSA explained between 47% and 57% of torque variance. Moment arm estimates explained 19% of the variance in isometric torque at 90°. These baseline data contribute to our understanding of factors influencing strength variation during childhood.
Wood is with the Department of Sport and Exercise Science, University of Portsmouth, St. Michael’s Building, White Swan Road, Portsmouth, PO1 2DT, UK; Dixon is with the School of Sport and Health Sciences, University of Exeter, Exeter, EX1 2LU, UK; Grant is with Somerset MRI Centre, Bridgwater, Somerset, TA6 6LQ, UK; Armstrong is with the Children’s Health and Exercise Research Centre, University of Exeter, EX1 2LU, UK, as was Wood at the time of the research.