Badminton preferentially decreases explosive over maximal voluntary torque in both the plantar flexors and extensors

We assessed changes in maximal and explosive plantar flexion (PF) and dorsi flexion (DF) torque, and thus the maximal and explosive DF/PF ratio, in response to successive badminton matches (2 × 35, 15 minutes of rest) in 16 juniors (10 males, 6 females) International‐level badminton players before (Pre), immediately after the first (Post‐1) and second (Post‐2) match as well as after resting for 12 hours. For both PF and DF, maximal voluntary torque decreased from Pre to Post‐2 (~7%‐9%; P < 0.05). Compared with Pre, PF explosive voluntary torque decreased by ~4%‐13% at Post‐1 (P < 0.05), with further reductions ranging from −15% to −25% within the 0‐100 ms epoch after contraction (P < 0.001) at Post‐2. Decrements of similar magnitude in DF explosive voluntary torque occurred at Post‐1 (ranging −7% to −27%) and Post‐2 (ranging −3% to −28%) relative to Pre (P < 0.05). All neuromuscular parameters were fully recovered after 12 hours of rest. Explosive DF/PF ratios during the very initial phase of contraction (up to 50 ms from onset) were lower compared with the maximal DF/PF ratio, with no effect of time (all P < 0.05). In badminton, explosive torque indices should be included to more accurately reflect acute fatigue induced by successive badminton matches

Biceps femoris long head muscle fascicle length does not differ between sexes

© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group. Hamstring strain injury (HSI) rates are higher for males vs. females. This cross-sectional study investigated if inherent differences in biceps femoris long head (BFLH) fascicle length (Lf) exist between recreationally active males and females (i.e., individuals without specific training practice history). Twenty-four young healthy participants (12 males; 12 females) had their BFLH muscle architecture (Lf, pennation angle [θp], and muscle thickness [MT]) measured using B-mode ultrasonography. Eccentric and isometric knee flexion strength were also assessed. BFLH Lf did not differ between sexes when expressed in absolute terms (males, 81.5 ± 14.7 mm; females, 73.6 ± 15.9 mm, P = 0.220, effect size (ES) = 0.52) or relative to femur length (0.140 ≤ P ≤ 0.220, ES = 0.63). Similarly, BFLH θp did not differ between sexes (P = 0.650) but BFLH MT was 18.9% larger for males vs. females (P = 0.024, ES = 0.99). Isometric and eccentric knee flexion strength was greater for males vs. females in absolute terms ([both] P < 0.001, 2.00 ≤ ES ≤ 2.27) and relative to body mass ([both] P < 0.001, 1.93 ≤ ES ≤ 2.13). In conclusion, factors other than BFLH Lf seem likely to be implicated in higher male vs. female HSI rates