Performance of Contemporary Dancers in Drop Jump Test Assessed by Reactive Strength Index

The aim of this research was to analyze the reactive strength index of contemporary dancers during the execution of a drop jump test. Sixteen contemporary dancers (24.2 +/- 3.9 years old, 1.62 +/- 0.05 m height, 57.7 +/- 6.8 kg mass, 15.6 +/- 3.1 time of practice) took part in the study. All volunteers executed the drop jump test from two heights with different positions of the arms (hands placed in the waist and arms free to execute a movement). The jumps were performed on an AMTI force plate and the volunteers were asked to perform tree trials in each condition in a randomized way. The average of the trials in each condition was taken. The reactive strength index (RSI) was computed using a custom Matlab code, and the results were compared using two-way repeated measures Anova (height and arms as factors). No significant differences were found between the different heights of the jump. A significant difference was observed comparing the position of the arms (p < 0.05). The jumps with the aiding movement of the arms had a greater RSI, so that the arms influence the performance of the RSI during the DJ. However, contemporary dancers have a poor performance in DJ compared to elite athletes, suggesting the necessity of a specific muscle/power training for improving their performance in dance leaps.