The Reliability Of The IMU-based Wearable Real-time Device To Measure Standing Long Jump For Preschoolers

PURPOSE: To evaluate the reliability of the kinematic performance of the lower extremity in the standing long jump (SLJ) using wearable IMU-based sensing devices for preschool children. METHODS: A total of 198 children aged 4 to 7 years (average 62.33 ± 11.64 months) participated in the SLJ test. Performance scores categorized the top and bottom 30% of participants into high and low-performance groups, respectively. Ten kinematic parameters were collected, including BMI, the variance of the center of gravity change (CGC), hip and knee joint angles during preparation (PRE hip, PRE knee) and take-off (TO hip, TO knee), overall average angular velocities of hip and knee joints from preparation to take-off (PRE-TO OAAV hip and knee), and distance. Pearson correlation analysis evaluated the relationship between variables and SLJ performance. One-way ANCOVA analyzed IMU signals, and stepwise regression identified key parameters impacting children's SLJ performance. RESULTS: The high-performance group was older (42.01%), taller (10.75%), heavier (18.35%), and had a lower BMI (3.65%) than the low-performance group (p < .05). Regarding the kinematic parameters of the lower extremity, the high-performance group demonstrated 21.74% decrease (from 70.8 to 90.77 degrees) in hip joint angle during preparation, and 15.93% reduction (from 85.33 to 101.55 degrees) in knee joint angle during preparation, and the change of the center of gravity was significantly lower than the low-performance group (34.06%, p < .05). The variables of age (r = 0.64), height (r = 0.50), weight (r = 0.35), PRE hip (r = -0.23), PRE knee (r = -0.23), and CGC (r = -0.16) significantly correlated with SLJ performance (p < .05). Furthermore, age, PRE knee, and PRE hip were the key factors that affect the SLJ performance of preschooler (R2 = 0.47). CONCLUSION: Results indicated wearable devices can be used to measure SLJ performed and verified a new algorithm for IMU-based motion tracking that combines traditional methods with technological devices to simultaneously gather motion data from multiple preschool children. Miniature and low-power IMU motion monitoring systems can be a tool which help to improve children's locomotor skills learning.