Childhood muscle morphology and strength: Alterations over six months of growth

• Published in: Muscle & nerve 2012-09, Vol.46 (3), p.360-366
• Main Authors: Pitcher, Christian A., Elliott, Catherine M., Williams, Sîan A., Licari, Melissa K., Kuenzel, Alex, Shipman, Peter J., Valentine, Jane P., Reid, Siobhán L.
• Format: Article
• Language: English
• Subjects: anatomical cross-sectional area; Biological and medical sciences; Child; Child, Preschool; children; Female; Fundamental and applied biological sciences. Psychology; Humans; Isometric Contraction - physiology; Magnetic Resonance Imaging; Male; Muscle Strength - physiology; muscle volume; Muscle, Skeletal - anatomy & histology; Muscle, Skeletal - growth & development; strength; Striated muscle. Tendons; Vertebrates: osteoarticular system, musculoskeletal system
• ISSN: 0148-639X; 1097-4598
• DOI: 10.1002/mus.23326

Introduction: The purpose of this study was to establish the nature and stability of the strength‐size relationship for the knee flexors and extensors across a 6‐month period of childhood growth. Methods: Nineteen typically developing children aged 5–11 years underwent lower limb magnetic resonance imaging (MRI) and dynamometry strength assessments on 2 occasions, 6 months apart. Muscle volume (MV) and maximum anatomical cross‐sectional area (aCSA) for the knee flexors and extensors were determined using MRI analysis software. Isokinetic dynamometry determined corresponding isometric and isokinetic strength. Results: Strong correlations were found between muscle size and strength for both the knee flexors and extensors (r = 0.84–0.90; P < 0.01). Furthermore, the ratio of strength to muscle size remained consistent across 6 months of prepubescent growth. Conclusions: Increases in thigh muscle strength were relative to those in muscle size, suggesting that muscle growth may play an important role in the development of strength during childhood. Muscle Nerve 46: 360–366, 2012