Effect of muscle length on voluntary activation of the plantar flexors in boys and men
2016
Kluka, Virginie | Martin, Vincent | Vicencio, Sebastian Garcia | Giustiniani, Mathias | Morel, Claire | Morio, Cédric | Coudeyre, Emmanuel | Ratel, Sébastien | Laboratoire des Adaptations Métaboliques à l'Exercice en Conditions Physiologiques et Pathologiques (AME2P) ; Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-UFR Sciences et Techniques des Activités Physiques et Sportives - Clermont-Auvergne (UFR STAPS - UCA) ; Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Clermont Auvergne [2017-2020] (UCA [2017-2020]) | Université Blaise Pascal - Clermont-Ferrand 2 (UBP) | Recherche et Développement ; Decathlon | CHU Clermont-Ferrand | Recherche et Développement ; Decathlon | Unité de Nutrition Humaine (UNH) ; Institut National de la Recherche Agronomique (INRA)-Université d'Auvergne - Clermont-Ferrand I (UdA)-Clermont Université | Université d'Auvergne - Clermont-Ferrand I (UdA) | Centre de Recherche en Nutrition Humaine d'Auvergne (CRNH d'Auvergne) | French National Agency of Technological Research (ANRT) 2012/0284
Virginie Kluka was supported by a grant of the French National Agency of Technological Research (ANRT), No2012/0284. The authors thank Dr. Nils Gueguen for his support along this study
显示更多 [+] 显示较少 [-]英语. The aim of the present study was to compare the effect of muscle length on the maximal voluntary activation level (VA) of the plantar-flexors between children and adults.Fourteen boys (10.0 ± 1.0 years) and fifteen men (24.6 ± 4.2 years) performed 5-s maximal isometric voluntary contractions (MVC) of the plantar-flexor muscles at seven ankle angles [from 10° in dorsi-flexion (DF) to 20° in plantar-flexion (PF); 0° = reference position; the angle between the plantar surface and leg is a right angle]. Single magnetic stimulations were delivered to the posterior tibial nerve during MVCs to determine VA.Results showed a higher absolute torque of the plantar-flexor muscles at long (10° DF) than at short muscle length (20° PF) in men (89.4 ± 19.4 vs. 46.8 ± 17.0 N m, P < 0.001) and boys (44.9 ± 18.5 vs. 26.6 ± 12.8 N m, P < 0.001). On average, VA was significantly higher in men than in boys (92.4 ± 1.7 vs. 87.6 ± 1.6 %, P < 0.05). However, no significant main effect of the ankle angle was observed on VA.The VA partly accounts for the plantar-flexors MVC torque difference between children and adults but is not affected by the muscle length changes in both groups. Therefore, VA cannot account for the shape of the torque–angle relationship on the plantar-flexor muscles
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