Test-Retest Reliability of Unilateral Horizontal Drop Jump in Children

Jumps are an indispensable activity for the development of coordination, muscle strength and power, especially in children. Positive effects of horizontal drop jump (HDJ) proved to be very important in improving individuals performance. HDJ presents a specific movement pattern that has similarities with running gait and take-off in different horizontal jumps. Influence and effect of implementating HDJ in children is yet to be determined. The aim of this research was to determine the test–retest reliability of the unilateral horizontal drop jump (UHDJ) in children of early school age (6–7 years). Participants ( n = 31; 19 girls and 12 boys) were school-age children that regularly attended Physical Education classes (Girls: mean age 7.5 ± 0.3 years, mean height 127.1 ± 6.8 cm and mean weight 25.8 ± 5.2 kg; Boys: mean age 7.5 ± 0.2 years, mean height 127.5 ± 6.9 cm and mean weight 27.6 ± 7.1 kg). UHDJ was performed from an elevation of 30 cm relative to the platform with starting position 120 cm from the middle of the platform. A jump on the platform and a unilateral take-off in the distance were performed, followed by a bilateral landing on the mat. Intraclass correlation coefficient was used to determine the reliability between the two days of measurements. Test–retest reliability was calculated for all observed variables, and a good correlation was found between the performed measurements (ICC = 0.76–0.89). The α coefficient indicates good to excellent (0.86–0.94) internal consistency. These findings suggest the usefulness of applying a UHDJ in school-age children. Moreover, it can be used to identify children talented for sports, monitor the effects of training and discover and direct individuals towards suitable sports disciplines.