Development of kinematic characteristics during jumping-rope movement in Japanese children aged 7–14 years

BACKGROUND: Young children exhibit immature swinging and jumping movements, which may increase rope trajectory variability. Sex-related differences may also be present in both the swinging and jumping movements. RESEARCH QUESTION: Do children aged 7-10 years exhibit immature swinging and jumping movements, and are there sex-related differences? METHODS: The participants included 12 children aged 7-10 years, 13 children aged 11-14 years, and 17 healthy young adults. The participants performed jumping-rope movements at a self-selected pace. Eight force plates were used to identify jumping and landing phases. A three-dimensional motion capture system was used to calculate toe clearance; rope trajectory variability; COM excursion; joint excursion of the shoulder, elbow, hip, knee, and ankle; and bilateral symmetry of joint movements. RESULTS: Children aged 7-10 years exhibited greater toe clearance, joint excursions across all joints, and COM excursions during the jumping and landing phases compared to the other groups. Additionally, children aged 7-10 years exhibited asymmetric movement patterns in their knee and ankle joints during the landing phase. Girls aged 7-10 years exhibited greater rope trajectory variability than same-age boys. SIGNIFICANCE: Children aged 7-10 years exhibited greater whole-body movements and COM fluctuations, indicating immature jumping movements as well as postural control during jumping-rope movements. In addition, girls aged 7-10 years demonstrate distinct rope-handling and postural control strategies relative to boys. These findings enhance our understanding of the developmental trajectory of motor and postural control during jumping-rope movements.