Determinants of ability to achieve ballistic stretch-shortening cycle movement. With special reference to strength and power.
- VernacularTitle:バリスティックな伸張―短縮サイクル運動の遂行能力を決定する要因 筋力および瞬発力に着目して
- Author:
KOJI ZUSHI
;
KAORU TAKAMATSU
- Publication Type:Journal Article
- Keywords:
stretch-shortening cycle movement;
ballistic movement;
rebound drop jump;
strength;
power
- From:Japanese Journal of Physical Fitness and Sports Medicine
1995;44(1):147-154
- CountryJapan
- Language:Japanese
-
Abstract:
Long jump and high jump, and several types of jumping and footwork with rapid changes in speed and direction of movement in ball games are characterized not only by a combination of eccentric and concentric movement (stretch-shortening cycle movement, SSC) but also a ballistic movement of very short duration (100-200 ms) . This study was conducted to examine the effects of strength and power on ballistic stretch-shortening cycle movement (BSSC) ability to clarify the methods of strength and power training necessary for jumpers and ball game players. The subjects were 99 male college athletes. The index for BSSC ability was RDJindex [RDJindex = (1/8⋅g⋅RDJta2) /RDJtc] which was calculated using contact time (RDJtc) and air time (RDJta) in a rebound drop jump from a height of 0.3 m with a small angular range of motion for the knee. The index for strength was maximum leg extension strength exerted in a squat position at a 90° knee angle (Smax/BW) . The index for power was the height of a counter movement jump (CMJh) . Results were summarized as follows;
(1) There were significant correlations between RDJindexand Smax/BW (r=0.219, p <0.05), RDJindexand CMJh (r=0.584, p<0.001), and Smax/BW and CMJh (r=0.487, p<0.001), but they were fairly low, suggesting that these indices do not have similar significance for estimating training effects and sports talent.
(2) There was no significant correlation between RDJtcand RDJta, of which the RDJindexwas composed (r=-0.145, ns) . This result suggests that BSSC ability consists of two independent abilities, i. e. the ability to jump higher and the ability to shorten one's movement time.
(3) There were significant correlations between RDJtaand Smax/BW (r=0.340, p<0.001), RDJtaand CMJh (r = 0.647, p <0.001), but not RDJtcand Smax/BW (r=0, 035, ns), or RDJtcand CMJh (r=-0.187, ns), suggesting that the ability to jump higher is affected by strength and power whereas the ability to shorten one's movement time is not.
(4) When subjects with equal RDJindexwere compared, one subject was dominant in RDJtc and another in RDJta. This result suggests that we should consider individual differences based on RDJtcand RDJtain training for increasing the RDJindex.
These findings seem to be useful to clarifying the methods of strength and power training for jumpers and ball game players who need to improve their ballistic stretch-shortening cycle movement ability.
