Norikazu Hirose

The aim of the present study was to clarify relationships among the distribution of birth month, maturation and body size in young soccer players. We therefore examined physical and maturational differences between selected players, who were considered to have higher potential to play soccer at a professional level as decided subjectively by coaches, and unselected players. Participants were 332 elite soccer players (mean age = 12.2 +/- 1.5 years; range = 9.1-15.0 years). Participants were divid

Hirose, N and Tsuruike, M. Differences in the electromyographic activity of the hamstring, gluteus maximus, and erector spinae muscles in a variety of kinetic changes. J Strength Cond Res 32(12): 3366-3372, 2018-This study aimed to clarify the differences in the electromyographic (EMG) activity of the semitendinosus (ST), semimembranosus (SM), biceps femoris long head (BFl), gluteus maximus (GM), and erector spinae (ES) muscles during leg curl and bridge exercises across different knee angles an

The purpose of this systematic review was to summarize the associations of eccentric force variables during jumping and eccentric lower-limb strength with vertical jump performance. A literature search was conducted in September 2022 using PubMed, Web of Science, and Scopus. Thirteen cross-sectional studies investigating the relationship between eccentric force and strength variables, such as force, rate of force development (RFD), power, time, and velocity, and vertical jump performance, includ

Yanaoka, T, Hamada, Y, Kashiwabara, K, Kurata, K, Yamamoto, R, Miyashita, M, and Hirose, N. Very-short-duration, low-intensity half-time re-warm up increases subsequent intermittent sprint performance. J Strength Cond Res 32(11): 3258-3266, 2018-This study investigated the effect of very-short-duration, low-intensity half-time re-warm up (RW) on subsequent intermittent sprint performance. Using a randomized cross-over design, 11 healthy men performed 3 trials. In the experimental trials, partici

The semitendinosus (ST) muscle is primarily used during Nordic hamstring exercise (NHE), which is often prescribed for preventing hamstring injury, though the biceps femoris long head (BFlh) muscle that is more susceptible to injuries. Thus, this study aimed to identify the modulation of BFlh muscle activity with different knee flexion angles during NHE using an inclined platform. Fourteen male athletes performed NHE and maintained their position at maximum inclination (NH). Subjects also perfor

CODp improves from 16 to 17 y of age in female players. Linear-sprint speed, muscle power, and body size were weakly correlated with the age differences in CODp.

In this study, the effect of biological maturity in developments of central information processing (CIP) evaluated from choice reaction time (CRT) was investigated from cross-sectional and longitudinal studies. The subjects were Japanese adolescent soccer players. Biological maturity was evaluated according to skeletal age. CRT was measured using the Talent–Diagnose– System. In the cross-sectional study, skeletal age correlated with CRT (r=−0.52, p<0.01), and there were some differences in devel

The purpose of this study was to clarify the differences in reaction time, stepping frequency and stepping endurance estimated by chronological age compared to skeletal age. The participants were 76 well-trained soccer players aged from 9.7 to 14.8 years old. Height and weight were measured before training. Their skeletal ages were evaluated by RUS score of TW II method. RUS score was calculated for skeletal age by Murata's method. Reaction time, stepping frequency and endurance were measured by