Interrater Reliability of the Modified Tuck Jump Assessment Scored by Physical Therapy Students

The Modified Tuck Jump Assessment (TJA) is a field-based, video-based tool used to evaluate movement faults relevant to anterior cruciate ligament (ACL) injury mechanisms. Although its reliability has been examined among experienced evaluators, its reliability when scored by novice evaluators remains unclear. This study investigated the interrater reliability of the Modified TJA when scored by physical therapy students without clinical experience.

This cross-sectional reliability study included 48 female high school soccer and rugby athletes from Japan. Participants performed the 10-second Modified TJA, comprising 10 movement-quality items scored from 0 to 2. Two final-year physical therapy students without clinical experience independently evaluated frontal and sagittal video recordings. Item-level agreement was assessed primarily using linear-weighted Cohen's kappa, with 95% confidence intervals estimated using a participant-level bootstrap with 20,000 resamples. Unweighted kappa and exact percentage agreement were calculated as secondary measures. Total-score reliability was assessed using ICC(2,1), a two-way random-effects model for single measurements and absolute agreement.

The total score demonstrated excellent interrater reliability (ICC(2,1) = 0.868; 95% CI, 0.775-0.924). Linear-weighted kappa coefficients for individual items ranged from 0.30 to 0.78; four items demonstrated substantial agreement, four demonstrated moderate agreement, and two demonstrated fair agreement. Six of the 10 items did not demonstrate substantial agreement, and several confidence intervals were wide. Exact agreement occurred in 356 of 480 item-level comparisons (74.17%) and ranged from 58.33% to 85.42% across items.

Two physical therapy students without clinical experience demonstrated excellent interrater reliability for the total Modified TJA score, whereas item-level agreement was heterogeneous and sometimes imprecise. These findings indicate consistency between the two student raters but do not establish scoring accuracy because their ratings were not compared with those of experienced evaluators or a criterion standard. Item-level results should therefore be interpreted alongside the total score, and standardized training should be evaluated before students use the Modified TJA independently.