Are Single Limb Hopping Scores the Same When Performed in a Physical Education Class Versus a Laboratory Setting in Uninjured Adolescents?: Implications for Future Rehabilitation Guidelines for Adolescents With Knee Injuries

This study compared the performance of adolescents (11-13 years old) in two environments with five single-limb hopping tasks. The purpose was to assess the reproducibility and responsiveness of single-limb hop tests in two environments (gymnasium and laboratory) for uninjured adolescents, and determine whether there are differences in baseline measures between males and females. Thirty-four participants (12 ± 0.3 years) were randomly assigned the gymnasium during a regularly scheduled physical education class or the laboratory and completed five single-limb hop tasks. Two weeks later, participants completed the tasks in the other location. The performances were evaluated for reproducibility (intra-class correlation coefficients [ICC], and standard errors of measurement [SEM]), and responsiveness (Bland-Altman analyses [BA], and smallest real difference [SRD]). Limb symmetry indices (LSI) were also calculated for each task. Two-way mixed ANOVAs examined location and sex differences. All hops were reproducible (ICC = 0.62-0.88) with SEMs ranging between 6.7-13.0% of the mean of the group. BA showed location differences for the triple hop on the dominant limb (d = -13.3 cm, p=0.03). SRDs ranged between 18.5-35.9% of the mean of the group for all hops. Males scored higher (percent difference (%D) = 9.9-21.4%, p<0.05) for all hops except the anterior hop on both limbs, the 6-meter timed hop and lateral hop on the non-dominant limb. LSIs were 93.5-102.6% and 94.4-101.7% for all hopping task for females and males, respectively. In conclusion, this battery of single-limb hop tests offer a reliable method for clinicians and researchers to assess the functional capacity of uninjured adolescents in various environments.