IMPULSES AND GROUND REACTION FORCES AT PROGRESSIVE INTENSITIES OF WEIGHTLIFTING VARIATIONS

Randall L. Jensen¹ and William P. Ebben².

¹Dept. HPER, Northern Michigan University, Marquette, MI, USA.  ²Dept. Physical Therapy, Program in Exercise Science, Marquette University, Milwaukee, WI, USA.

Five Division-I athletes who routinely performed the hang clean and hang snatch performed a single repetition of each at loads of 50, 60, 70, 80, and 90% of their 1 RM, with 5 minutes rest between each repetition. Movement impulses and peak GRF were evaluated on an AMTI force plate. Two-way ANOVA indicated impulses and peak GRF at 50% 1RM were lower than all other reps (p<0.05) and that 60% RM was less than 80% and 90%. Also the 70% repetition was less than 90% RM (p<0.05). Despite the fact that the 1RM loads were 50% higher for the hang clean than the hang snatch (133 vs. 88 kg), no differences in impulse were found between the two exercises (p>0.05). These results suggest other variables such as exercise form and movement velocity mediate the amount of impulse and/or force developed.