Active range of motion in the hip joint and balance in judo athletes

Abstract

Introduction with Problem Statement and Approach: Judo is an Olympic combat sport demanding high levels of neuromuscular coordination and joint mobility. While the biomechanical relationship between lower limb flexibility and postural control is documented in adults, there is a notable gap regarding the coordinative profiles of prepubescent children. To address this problem, this observational cross-sectional study aimed to examine the correlation between the active range of motion (AROM) of the hip joint and postural stability in young judo athletes, focusing on how specific mobility patterns influence balance during early sports specialization. Material and Methods: The sample consisted of 29 male judokas aged 7–14 years (mean age 9.5 ± 2.27) with at least one year of consistent training experience. All participants declared right-side dominance. Hip AROM was measured bilaterally using a universal goniometer for flexion, extension, abduction, adduction, and rotation, adhering to standardized clinical assessment protocols. Postural stability was evaluated on a CQStab2P stabilometric platform during a 30-second quiet standing task with eyes open, focusing on the displacement of the center of pressure (COP). Results: Significant correlations were observed between hip mobility and balance metrics, occurring primarily in the left (non-dominant) lower limb in the frontal plane. The direction of these relationships differed significantly: a greater left hip abduction range was associated with improved stability (lower sway amplitude), whereas an increased left hip adduction range was related to reduced postural stability. The right lower limb showed almost no significant impact on balance parameters. Discussion: These findings indicate the early presence of marked functional asymmetry in young judo athletes. This phenomenon likely stems from the dominant role of the left limb as the primary weight-bearing "supporting leg" during the kuzushi and tsukuri phases of right-sided technical actions (throws), compounded by a general lack of bilateral training emphasis. This specific biomechanical loading adapts the limbs to different functional tasks, fundamentally linking support leg mobility to overall balance. Conclusions: Addressing these mobility-related stability deficits is crucial for optimizing motor development and preventing future injuries. The results highlight the necessity of incorporating targeted physiotherapeutic and conditioning exercises designed to strengthen the eccentric control of the adductor muscles. Furthermore, coaches should implement strategies that promote bilateral motor proficiency to mitigate the effects of unilateral dominance. By balancing hip mobility and enhancing neuromuscular control, practitioners can improve the foundational balance required for competitive performance.