The specificity of leg strength and power in several sport athletes

Abstract

Ab8trut This study clarified 山 e specificity oneg strength and power in se ▼eral spOrt ath 且 etes ． To accomphsh this purpose ， a new physica 畳 正 itness test was developed to evaluate the capacity for the ba艮 且 istic and stretch − shortening cyc 且 e （ SSC）movements ． 1．The drop jump（ DJ） ，atypical SSC movement was used in this test ． A few experi − ments were performed to determine the best droppi皿 g height and jumping technique of DI in 10college ma 】 e athletes ． These resu 且 ts showed the best method of DI was rebound DJ with sma 且 ［angular displacement of the knee from O ． 3mbecause of appearing the shortest con ・ tact time and the longest air time ， and being ballistic and safe movernent ． 2．Average force〔 Finde 翼 冨 lta ／ 2 十 （ 2 ・ hd／ g） 1／21 ／ tc十 1 〕，average power 〔 Pincle 翼 ＝ lg ・ （ t ／ 2） 2 − 2 。 h ，｝ ／（ 2 ・ tc ） 〕and the capacity to jump higher within shorter contact time〔 DJindex ・ ＝ （ 1／ 8 。 g 。 2 ） ／ 魅〕are calculated by using cont3ct time （ ），air time （ ta）and dropping height （ 隔） of 以 ， and g ｛ 9． 81 m ／ s2） ． Interrelationships between Dlind 。罵 Findex ， Pincle 寛 tc and ts were examined in 93 male ath 且 etes of 14 sport events ． These results showed the best i 皿 dex was DJinde 翼 because of reflecting both Finder and Pindex ， and tc and ta ． 3 ．The specificity of ■ eg strength and power was investigated by comparing with DJin ・ dex height of counter movement j 皿 mp （ CMJ − H ）and maximum strength exerted by squat posture at 90 ひ of knee angle （ S − MAX ） in 93 ma 且 e athletes o 正 14 sport events ． This resu 且 t showed all sport athletes were grouped into A ， B and C typeJumper and sprinter ， gymnast and kendo atheletes be且 onged to A type which showed the character of 且 arge in order of DJindex ， C！ 呀 一 H and S − MAX ， Skater． ski jumper and swimmer belonged to B type which showed contrary character of A type， Ball game p ［ ayer and 量 ong distance runner belonged to C type ． which did not show difference among them ． But exce 亘 lent p 且 ayers for jump and 置 botwork in ball games showed 山 e same character as jumper and sprinter ． These resu 且 ts lead to the conclusion that we shou 且 d evaluate not on 晝 y the general Ieg strength and power but a且 so the capacity for the ba且 listic and SSC 皿 oveme 皿 t by measuring DJinde 麗 when coaches scout f ｛ ） r spOrt talents and athletes practice the training according to speci' icity of strength and power 、 lt shou 亘 d a 且 so be added that DJindex is a practica 且 index which can be simply and exactly measured by using matswitch ． '