Quantification of strengths of selected segments of the body is essential to predict their influence in weightlifting. The purpose of this study was to quantify back strength and leg strength, and to predict the clean and jerk and the snatch using back strength, leg strength and body weight as independent variables. Twenty-three weightlifters were randomly selected from 40 volunteers to serve as subjects. A spring dynamometer was used to measure back and leg strength. Subjects performed three trials of a maximum jerk, snatch, back lift and leg lift. A stepwise regression model was used to predict the performance in the jerk and snatch based upon back strength, leg strength and the body weight of the lifter. It was concluded that back strength and leg strength are equally influential in predicting performance of the jerk. In the snatch, leg strength and body weight are more influential than back strength. Multiple regression equations of the dependent variables jerk (J) and snatch (S), and the independent variables body weight (W), back strength (B) and leg strength (L) are as follows:
(1) J = -14.02 + 0.24W + 0.29B + 0.30L
(2) S = 1.70 + 0.35W - 0.2B + 0.31L
Multiple regression equations of the dependent variables jerk (J) and snatch (S) and the two best predictor independent variables are as follows:
(3) J = -12.46 + 0.40B + 0.27L
(4) S = 0.73 + 0.34W + 0.30L
The three-variable model for the jerk equation 1 and the snatch equation 2 was found to be the better regression model because the R-square value is 0.76 and 0.64 for jerk and snatch, respectively. The coach and the weightlifter can use these regression models to monitor the progress in performance of the jerk and snatch during training.
(C) 1990 National Strength and Conditioning Association