The side hop test: Validity, reliability, and quality aspects in relation to sex, age and anterior cruciate ligament reconstruction, in soccer players

Objective: To study the side hop test regarding validity, reliability, and quality in relation to sex, age and ACL-reconstruction in soccer players.Design: Cohort study. Participants: 117 females with a primary ACL-reconstruction, and 119 females, 46 males (age 16-26 years), 49 girls and 66 boys (age 13-16 years) without injury.Main outcome measures: For convergent validity, one physiotherapist analysed side hops live and later on video. One physiotherapist and two physiotherapy students analysed side hops from 92 players for interrater reliability (video). For intrarater reliability, side hops from 35 players were analysed twice (video). Quality aspects (flaws), i.e. number of times the hopping limb touched the strips, the nonhopping limb touched the floor, and double hops/foot turns with the hopping limb, were registered (video).Results: Convergent validity was excellent; the intraclass correlation coefficient (ICC) was 0.93-1.0. All reliability measures were excellent (ICC 0.92-1.0). Adult male players had fewest and girls had most flaws, especially double hops/foot turns with the hopping limb, compared with all other players (mean, 11-12 vs 1-6, h2 = 0.18, large effect size). No differences were reported between knee-healthy and ACLreconstructed females.Conclusion: The side hop test is valid and reliable. Quality aspects differ between sexes and ages.& COPY; 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).