Unipodal closed-chain lower body training and its effect on lower limbs asymmetries in junior players of the Chilean handball team

Introduction. Handball is a high-intensity sport that imposes asymmetric loads on the lower limbs, especially in movements such as jumping and feinting. Objective: This study aimed to identify asymmetries and assess the effect of a 12-week strength and power training program on the jumping ability of junior players of the Chilean handball team.Methodology: With a quasi-experimental design, strength and plyometric exercises were ap-plied in 12 microcycles. Each week included three 90-minute sessions before the technical-tac-tical training. 16 male junior players participated, with an average age of 20.6 ± 1.9 years, weight of 84.9 ± 8.4 kg and height of 183.8 ± 5.1 cm, and an average handball experience of 9 ± 2 years. The performance tests included squat jump (SJ), counter movement jump (CMJ), drop jump (DJ), from 30 cm and unipodal abalakov (ABK), using the “My Jump 2” application. Results: The results showed a significant increase injump height in all tests (p < .05), with im-provements between 12% and 17% in SJ, ABK, CMJ and DJ. Body mass varied by 10% between initial and final assessments.Discussión: Although there were no significant differences in initial and final asymmetries, a reduction in strength and power disparities was observed after the program, improving jump height performance. Conclusions: The training program slightly reduced asymmetries and led to significant im-provements in bipodal jumping ability in young handball players.