Effects of Integrative Neuromuscular Training on Unilateral and Bilateral Lower-Extremity Sports Performance in Adolescent Female Sprinters: A Randomized Controlled Trial

Abstract

Background: Adolescent female athletes often exhibit more pronounced lower-limb asymmetry due to physiological differences, increasing injury risk. Despite documented efficacy in team sports for injury mitigation and performance enhancement, integrative neuromuscular training (INT) effects on unilateral and bilateral lower-limb capabilities in trained adolescent female sprinters remain undetermined. Hypothesis: We hypothesized that an 8-week INT program would significantly improve unilateral and bilateral lower-extremity performance measures in adolescent female sprinters compared with traditional sprint-specific training. Study Design: Randomized controlled trial. Level of Evidence: Level 1. Methods: Twenty-four national second-level adolescent female sprinters (aged 16-18 years) were randomly assigned to an 8-week INT group ( n = 12) or a control group (CON, n = 12) that continued traditional sprint-specific training. Measurements obtained before and after the intervention included the hop test, star excursion balance test (SEBT), 3-repetition maximum (3RM) unilateral and bilateral back squat, 100-m run, standing long jump (SLJ), and limb symmetry index (LSI). Results: After the intervention, the INT group outperformed the CON group on the nondominant side in all hop tests ( P < 0.001; η p ² = 0.74-0.88), six directions of the SEBT ( P < 0.001; η p ² = 0.44-0.88), and the 3RM unilateral back squat ( P < 0.01; η p ² = 0.65). On the dominant side, the INT group also outperformed the CON group in the single hop for distance ( P < 0.001; η p ² = 0.80) and three directions of the SEBT ( P < 0.01; η p ² = 0.38-0.84). In addition, the INT group showed significantly greater improvements than the CON group in the LSI from unilateral tests (all P < 0.01; η p ² = 0.26-0.88), as well as in the 100-m run and SLJ ( P < 0.001; η p ² = 0.61-0.69). Conclusion: The 8-week INT program was associated with improvements in dynamic balance, explosive power, and limb symmetry in adolescent female sprinters, with greater benefits observed on the nondominant side. Clinical Relevance: INT is an effective training modality for improving lower-limb performance and mitigating asymmetry in adolescent female sprinters.