caa a22 4500 46794086X CHVBK 20180406153012.0 cr unu---uuuuu 170328e20060201xx s 000 0 eng 10.1007/s00421-005-0087-3 doi (NATIONALLICENCE)springer-10.1007/s00421-005-0087-3 Effects of isometric squat training on the tendon stiffness and jump performance [Elektronische Daten] [Keitaro Kubo, Hideaki Yata, Hiroaki Kanehisa, Tetsuo Fukunaga] The present study aimed to investigate the effect of isometric squat training on human tendon stiffness and jump performances. Eight subjects completed 12weeks (4days/week) of isometric squat training, which consisted of bilateral leg extension at 70% of maximum voluntary contraction (MVC) for 15s per set (10sets/day). Before and after training, the elongations of the tendon-aponeurosis complex in the vastus lateralis muscle and patella tendon were directly measured using ultrasonography while the subjects performed ramp isometric knee extension up to MVC. The relationship between the estimated muscle force and tendon elongation was fitted to a linear regression, the slope of which was defined as stiffness. In addition, performances in two kinds of maximal vertical jumps, i.e. squatting (SJ) and counter-movement jumps (CMJ), were measured. The training significantly increased the volume (P<0.01) and MVC torque (P<0.01) of the quadriceps femoris muscle. The stiffness of the tendon-aponeurosis complex increased significantly from 51±22 (mean±SD) to 59±24N/mm (P=0.04), although that of the patella tendon did not change (P=0.48). The SJ height increased significantly after training (P=0.03), although the CMJ height did not (P=0.45). In addition, the relative difference in jump height between SJ and CMJ decreased significantly after training (P=0.02). These results suggest that isometric squat training changes the stiffness of human tendon-aponeurosis complex in knee extensors to act negatively on the effects of pre-stretch during stretch-shortening cycle exercises. Springer-Verlag, 2005 Resistance training nationallicence Elongation nationallicence Ultrasonography nationallicence Vastus lateralis muscle nationallicence Kubo Keitaro Department of Life Science (Sports Sciences), University of Tokyo, Komaba 3-8-1, Meguro-ku, 153-8902, Tokyo, Japan aut Yata Hideaki Sports Science Laboratory, Wako University, Machida, Tokyo, Japan aut Kanehisa Hiroaki Department of Life Science (Sports Sciences), University of Tokyo, Komaba 3-8-1, Meguro-ku, 153-8902, Tokyo, Japan aut Fukunaga Tetsuo Department of Sports Sciences, Waseda University, Tokorozawa, Saitama, Japan aut European Journal of Applied Physiology Springer-Verlag 96/3(2006-02-01), 305-314 1439-6319 96:3<305 2006 96 421 https://doi.org/10.1007/s00421-005-0087-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00421-005-0087-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kubo Keitaro Department of Life Science (Sports Sciences), University of Tokyo, Komaba 3-8-1, Meguro-ku, 153-8902, Tokyo, Japan aut NATIONALLICENCE 700 1- Yata Hideaki Sports Science Laboratory, Wako University, Machida, Tokyo, Japan aut NATIONALLICENCE 700 1- Kanehisa Hiroaki Department of Life Science (Sports Sciences), University of Tokyo, Komaba 3-8-1, Meguro-ku, 153-8902, Tokyo, Japan aut NATIONALLICENCE 700 1- Fukunaga Tetsuo Department of Sports Sciences, Waseda University, Tokorozawa, Saitama, Japan aut NATIONALLICENCE 773 0- European Journal of Applied Physiology Springer-Verlag 96/3(2006-02-01), 305-314 1439-6319 96:3<305 2006 96 421 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer