其他标题：The characteristics of takeoff movement and joint kinetics during the rebound-type jump using single-leg takeoff: comparison with the rebound-type jump using double-leg takeoff
出版社：Japan Society of Physical Education, Health and Sport Sciences
摘要：The present study was conducted to clarify points for attention, and to determine an effective method for the single-leg rebound-type jump (SRJ) and double-leg rebound-type jump (DRJ) in plyometrics, by investigating the joint kinematics and kinetics of the takeoff leg in the sagittal plane. Twelve male track and field athletes (sprinters and jumpers) performed the SRJ and DRJ with maximal effort. Jumping motions in the sagittal plane were videotaped with a high-speed video camera (300 Hz), and ground reaction force was recorded with a force platform (1000 Hz). Kinematics and kinetics were calculated. To evaluate the force output characteristics for a single leg in the DRJ, the ground reaction force was divided into half, and the data were used to calculate the other kinetic parameters. The overall results of these analyses were as follows: 1. In the SRJ, the jump height for a single leg and the landing height for a single leg were higher than in the DRJ because of the higher mechanical power used during the eccentric and concentric phases. 2. In the SRJ, the negative relative work at the ankle joint was smaller and the negative and positive relative work at the hip joint was larger than in the DRJ. These results affected the characteristics of the SRJ in that although the jump height was higher for a single leg because of the greater mechanical work, the force output time was longer. 3. In the SRJ, the joint extension torque at the hip joint was larger than that in the DRJ. This may have been caused by the greater landing height for a single leg, higher body weight on a single leg, and the leg swing motion. 4. The RJ-index for the SRJ was correlated with that for the DRJ. Moreover, the RJ-index for the SRJ was affected by the joint torque and joint torque power at the ankle and hip joints. These results suggest that the DRJ and SRJ are effective training tools for improving both technique and force output ability in order to (1) prioritize the power output at the ankle plantar flexor in the DRJ and (2) prioritize the power output at the hip extensor and increase the ground reaction force and hip extension torque by leg swing motion for the SRJ. These findings are useful for clarifying the points for attention and for developing an effective method of using the SRJ and DRJ in plyometrics.
其他摘要：The present study was conducted to clarify points for attention, and to determine an effective method for the single-leg rebound-type jump (SRJ) and double-leg rebound-type jump (DRJ) in plyometrics, by investigating the joint kinematics and kinetics of the takeoff leg in the sagittal plane. Twelve male track and field athletes (sprinters and jumpers) performed the SRJ and DRJ with maximal effort. Jumping motions in the sagittal plane were videotaped with a high-speed video camera (300 Hz), and ground reaction force was recorded with a force platform (1000 Hz). Kinematics and kinetics were calculated. To evaluate the force output characteristics for a single leg in the DRJ, the ground reaction force was divided into half, and the data were used to calculate the other kinetic parameters. The overall results of these analyses were as follows: 1. In the SRJ, the jump height for a single leg and the landing height for a single leg were higher than in the DRJ because of the higher mechanical power used during the eccentric and concentric phases. 2. In the SRJ, the negative relative work at the ankle joint was smaller and the negative and positive relative work at the hip joint was larger than in the DRJ. These results affected the characteristics of the SRJ in that although the jump height was higher for a single leg because of the greater mechanical work, the force output time was longer. 3. In the SRJ, the joint extension torque at the hip joint was larger than that in the DRJ. This may have been caused by the greater landing height for a single leg, higher body weight on a single leg, and the leg swing motion. 4. The RJ-index for the SRJ was correlated with that for the DRJ. Moreover, the RJ-index for the SRJ was affected by the joint torque and joint torque power at the ankle and hip joints. These results suggest that the DRJ and SRJ are effective training tools for improving both technique and force output ability in order to (1) prioritize the power output at the ankle plantar flexor in the DRJ and (2) prioritize the power output at the hip extensor and increase the ground reaction force and hip extension torque by leg swing motion for the SRJ. These findings are useful for clarifying the points for attention and for developing an effective method of using the SRJ and DRJ in plyometrics.
关键词：プライオメトリックトレーニング;-;伸張―短縮サイクル;関節トルク;関節トルクパワー
其他关键词：plyometric training ; stretch-shortening cycle ; joint torque ; joint torque power
