Effect of muscle-tendon properties in determining the height of optimal individual drop jump

Objective: The aim of this study is to determine the individual optimal drop jump (DJ) fall height and its relationship with muscle-tendon properties. Method: 13 athletes from Konyaaltı Municipality Sports Club Women's Handball Team, between the ages of 17-26, playing at the super league level, participated in the study. Participants were asked to perform DJ performances from different fall heights (30-35-40-45-50-55-60 cm) on different days. Jumps with a ground contact time of ≤ 250 ms were taken into consideration, with each participant trying twice. Each performance was recorded with a camera placed in the lateral direction and the jump phases were analyzed by kinematic analysis method. Achilles tendon moment arm lengths were also determined with the help of the analysis of the photograph taken from the dominant foot. Results: It has been observed that the jump height (hjump) and reactive force index (RSI) values of the performances performed by DJ40 give significantly larger results than other heights, and the ground contact time (tcontact) values of the performances performed by DJ60 and DJ40 give significantly smaller results than other heights. Hip angle (hip) value obtained from DJ40 was significantly higher than hip value obtained from DJ30 (p<0.05). The forefoot length (Lforefoot) variable was negatively correlated with DJ40 (p<0.05). A positive correlation was determined with the Achilles tendon moment arm (Lachilles) variable knee(35), knee(40) and tcontact(50) Conclusion: In this study, which aimed to determine the optimal drop jump heights of athletes, it was observed that jumps made from DJ40 drop height gave significantly better results in terms of hjump, tcontact, RSI parameters than other heights. It has been observed that maximum efficiency is obtained from the DJ40 drop height and it carries the minimum risk of injury. It was determined that the optimal DJ drop height value of the participants was between 35 cm and 40 cm