Affiliations: [a] Valley Hospital Sports Institute, Ridgewood, NJ 07450, USA | [b] University of Florida, Gainesville, FL 32611, USA | [c] Curry School of Education, University of Virginia, Charlottesville, VA 22903, USA
Note: [*] Corresponding author. Memorial Gymnasium, University of Virginia, Charlottesville, VA 22903, USA. Tel.: +1 804 924 6187, fax: + 1 804 924 1389.
Abstract: The purpose of this study was to determine how isokinetic eccentric and concentric peak torque/body weight ratios and time to peak torque values relate to drop vertical jump heights in 30 healthy subjects (12 men and 18 women, age =22.7±2.2 yr, ht =169.6±8.9 em, wt =67.2±11.9 kg). Drop vertical jumps were performed from a box 50 cm high. Subjects were tested isokinetically on each leg for the motions of knee extension and ankle plantar flexion. Eccentric and concentric peak torque (PT)/body weight ratios along with time (s) to eccentric and concentric peak torque were extracted from the Kin Com II computer. A stepwise multiple regression analysis was conducted to determine the relationship between the eight predictor variables and drop vertical jump height. Knee extension concentric PT/body weight ratio was the most significant predictor of drop vertical jump height, accounting for 23% of the variance. This finding suggests that the stretch-shortening cycle can be simulated using isokinetic strength measurements and that drop vertical jump height can be attributed in part to concentric knee extension strength.
Keywords: Eccentric, Concentric, Peak torque, Time to peak torque, Plyometric
