Journal of Scientific Coaching for Training
Online ISSN : 2434-3307
Print ISSN : 2433-6742
Volume 1 , Issue 1
Showing 1-2 articles out of 2 articles from the selected issue
  • Yohei Shimokochi, Takahiro Igawa, Yumi Watanabe, Hiroyuki Abutani, Mak ...
    2014 Volume 1 Issue 1 Pages 4-9
    Published: 2014
    Released: March 30, 2020
    We examined the relationship of the ability to perform a rebound jump (RJ) using the takeoff leg (the leg used to takeoff when throwing a handball into a goal) or the non-takeoff leg with the double-leg squat 1RM (SQ1RM) and the maximum squat jump power (SQJP). Nineteen college female handball players participated in the study. They performed double-leg squats and jumps with different loads to determine their SQ1RM and SQJP values, and 10 consecutive single-leg RJs on a mat switch; the contact time, jump height, and RJIndex (= jump height/contact time) were determined as indicators of RJ performance. Linear regression analyses were performed to predict each RJ performance indicator for the takeoff and non-takeoff legs separately with SQ1RM or SQJP. The results showed that, for the takeoff legs, higher SQ1RM (R2 = 0.235~0.454, p < 0.05) and SQJP (R2 = 0.238~0.426, p < 0.05) values significantly relate to greater jump height and RJIndex and shorter contact time. For the non-takeoff legs, a significant positive correlation was seen only between SQ1RM and RJIndex (R2 = 0.158, p < 0.05), indicating that SQ1RM and SQJP may only reflect the capacity to perform RJs in the takeoff legs of female players. Thus, for these athletes, it is necessary to establish reliable single-leg squat 1RM and squat jump power measurements to assess each leg’s strength. Further, our results suggest that training programs for athletes with lower extremity bilateral neuromuscular asymmetry should focus more on single-leg closed kinetic chain exercises to effectively train both legs.
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  • Masaaki Kanno, Yuki Shiga, Masato Amano, Norihiro Shima
    2014 Volume 1 Issue 1 Pages 10-15
    Published: 2014
    Released: April 03, 2020
    The purpose of the present study was to examine changes in mobility and joint angular velocity of the lower extremities after high-speed combination squat training, which is a high-speed chair standing-up training with an additional plantar flexion task. Twelve trained elderly women (age: 67±3.2 years old) performed resistance exercises and high-speed combination squat in which an operating characteristic with regard to moving capability is similar, using their body weight once a week for 16 weeks. After exercise intervention, the subjects were classified into two groups on the basis of the change in walking or stair ascent times (6 high and 6 low improvement groups), respectively. Hip joint angular velocity improved significantly for the group that demonstrated the high improvement in walking time compared with the low improvement group. Knee (d =0.87) and ankle (d =0.89) joints angular velocities increased in the group with the high improvement in the 12 steps stair ascent time compared with the low improvement group. These results suggest that improvement in walking or stair ascent abilities were affected by hip joint angular velocity or knee and ankle joints angular velocities, respectively.
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