The multiple hop test: a discriminative or evaluative instrument for chronic ankle instability?

OBJECTIVE

To determine whether the multiple hop test should be used as an evaluative or a discriminative instrument for chronic ankle instability (CAI).

DESIGN

Blinded case-control study.

SETTING

: University research laboratory.

PARTICIPANTS

Twenty-nine healthy subjects (21 men, 8 women, mean age 21.8 years) and 29 patients with CAI (17 men, 12 women, mean age 24.9 years) were selected.

INTERVENTIONS

Subjects performed a multiple hop test and hopped on 10 different tape markers while trying to avoid any postural correction.

MAIN OUTCOME MEASURES

Minimal detectable changes (MDC) of the number of balance errors, the time value, and the visual analog scale (VAS) score (perceived difficulty) were calculated as evaluative measures. For the discriminative properties, a receiver operating characteristic curve was determined and the area under curve (AUC), the sensitivity, specificity, diagnostic accuracy (DA), and likelihood ratios (LR) were calculated whether 1, 2, or 3 outcomes were positive.

RESULTS

Based on their MDC, outcomes should, respectively, change by more than 7 errors (41%), 6 seconds (15%), and 27 mm (55%, VAS score) before considering it as a real change. Area under curves were, respectively, 79% (errors), 77% (time value), and 65% (VAS score). The most optimal cutoff point was, respectively, 13.5 errors, 35 seconds, and 32.5 mm. When 2 of 3 outcomes were positive, the sensitivity was 86%, the specificity was 79%, the DA was 83%, the positive LR was 4.2, and the negative LR was 0.17.

CONCLUSIONS

The multiple hop test seems to be more a discriminative instrument for CAI, and its responsiveness needs to be demonstrated.