Child-adult Differences in the Kinetics of Torque Development
Overview
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Children have lower size-normalised maximal voluntary force, speed, and power than adults. It has been hypothesised that these and other age-related performance differences are due to lesser type-II motor-unit utilisation in children. This should be manifested as slower force kinetics in explosive muscle contractions. The purpose of this study was to investigate the nature of child-adult force-kinetics differences and whether the latter could support that hypothesis. Untrained boys (n = 20) and men (n = 20) (10.1 ± 1.3 and 22.9 ± 4.4 years, respectively), performed maximal, explosive, isometric elbow flexions and knee extensions on a Biodex dynamometer. Peak torque (MVC), times to 10-100% MVC, and other kinetics parameters were determined. The boys' body-mass-normalised knee extension MVC, peak rate of torque development, and %MVC at 100 ms were 26, 17 and 23% lower compared with the men and their times to 30% and 80% MVC were 24 and 48% longer, respectively. Elbow flexion kinetics showed similar or greater differences. The findings illuminate boys' inherent disadvantage in tasks requiring speed or explosive force. It is demonstrated that the extent of the boys-men kinetics disparity cannot be explained by muscle-composition and/or musculo-tendinous-stiffness differences. We suggest therefore that the findings indirectly support children's lower utilisation of type-II motor units.
Joint position and force senses in young female tennis players and untrained adolescents.
Niespodzinski B, Waldzinski T, Durzynska A, Mieszkowski J, Knas M, Kochanowicz A PLoS One. 2024; 19(10):e0312483.
PMID: 39436925 PMC: 11495642. DOI: 10.1371/journal.pone.0312483.
Keles C, Ates F Front Bioeng Biotechnol. 2023; 11:1287385.
PMID: 38116195 PMC: 10728775. DOI: 10.3389/fbioe.2023.1287385.
Rock K, Addison O, Gray V, Henshaw R, Ward C, Marchese V Children (Basel). 2023; 10(1).
PMID: 36670664 PMC: 9856749. DOI: 10.3390/children10010114.
Elbow Joint Position and Force Senses in Young and Adult Untrained People and Gymnasts.
Niespodzinski B, Mieszkowski J, Sawczyn S, Kochanowicz K, Szulc A, Zasada M Int J Environ Res Public Health. 2022; 19(13).
PMID: 35805246 PMC: 9265726. DOI: 10.3390/ijerph19137592.
Strength Abilities and Serve Reception Efficiency of Youth Female Volleyball Players.
Pawlik D, Dziubek W, Rogowski L, Struzik A, Rokita A Appl Bionics Biomech. 2022; 2022:4328761.
PMID: 35694275 PMC: 9177318. DOI: 10.1155/2022/4328761.