Associations Between Gross Motor Coordination and Agility, Flexibility, and Single-Leg Hop Performance in 12–14 Year Olds

This study aimed to examine the associations between gross motor coordination, agility, flexibility, and single-leg hop performance in children aged 12–14 years. A total of 964 healthy children aged 12–14 (47.82% girls, 52.18% boys) participated in the study. To assess children’s motor development levels, the KTK was used; flexibility was measured using the Sit and Reach Test, agility was assessed with the Pro-Agility Test, and three different Single-Leg Hop Tests were used to evaluate lower-extremity functional performance, muscle strength, dynamic balance, coordination, and motor control. Participants’ KTK total, KTK sub-parameter scores, single leg hop for distance, crossover hop for distance, and 90° medial rotation hop test results increased with age and showed significant differences across age groups and gender (p < .001). Agility performance increased significantly with age in both girls and boys, as seen in the reduction in Pro-Agility test times (p < .001). Flexibility improved significantly with age in girls (p < .001), whereas no significant age-related change was observed in boys (p > .05). Additionally, higher motor skill levels were associated with higher single leg hop for distance, crossover hop for distance, rotation hop, and agility scores in both genders, with significant gender differences (p < .001). These findings indicate that motor performance improved significantly with age and was positively associated with gross motor coordination. This finding supports the idea that motor coordination and jumping-based skills develop positively during childhood. The significant increase in agility scores in both girls and boys with age indicates that agility develops with age. In terms of flexibility, gender-based differences have been observed; this suggests that flexibility develops differently depending on gender-specific biomechanical and physiological factors. Cite this article as: Karadeniz, S., Akgün, S., Anıl, B., Akdemir, E., Salkılı., E. K., Kabadayı, M., Kumru, D., & Yılmaz, A. K. (2026). Associations between gross motor coordination and agility, flexibility, and single-leg hop performance in 12–14 year olds. Research in Sports Science, 16, 0025, doi: 10.5152/rss.2026.26025.