Different relationships of single-leg rebound jump performance using takeoff and non-takeoff legs with double-leg squat 1RM and squat jump maximum power in college female handball players

Abstract

We examined the relationship of the ability to perform a rebound jump (RJ) using the takeoff leg (the leg used to takeoff when throwing a handball into a goal) or the non-takeoff leg with the double-leg squat 1RM (SQ1RM) and the maximum squat jump power (SQJP). Nineteen college female handball players participated in the study. They performed double-leg squats and jumps with different loads to determine their SQ1RM and SQJP values, and 10 consecutive single-leg RJs on a mat switch; the contact time, jump height, and RJ_Index (= jump height/contact time) were determined as indicators of RJ performance. Linear regression analyses were performed to predict each RJ performance indicator for the takeoff and non-takeoff legs separately with SQ1RM or SQJP. The results showed that, for the takeoff legs, higher SQ1RM (R² = 0.235~0.454, p < 0.05) and SQJP (R² = 0.238~0.426, p < 0.05) values significantly relate to greater jump height and RJ_Index and shorter contact time. For the non-takeoff legs, a significant positive correlation was seen only between SQ1RM and RJ_Index (R² = 0.158, p < 0.05), indicating that SQ1RM and SQJP may only reflect the capacity to perform RJs in the takeoff legs of female players. Thus, for these athletes, it is necessary to establish reliable single-leg squat 1RM and squat jump power measurements to assess each leg’s strength. Further, our results suggest that training programs for athletes with lower extremity bilateral neuromuscular asymmetry should focus more on single-leg closed kinetic chain exercises to effectively train both legs.