Test-Retest Reliability and Practice Effects of the Stability Evaluation Test.

Abstract

Postural control plays an essential role in concussion evaluation. The Stability Evaluation Test (SET) aims to objectively analyze postural control by measuring sway velocity on the NeuroCom VSR portable force platform (Natus, San Carlos, CA). To assess the test-retest reliability and practice effects of the SET protocol. Cohort. Research laboratory. 50 healthy adults (20 men, 30 women, age 25.30 ± 3.60 y, height 166.60± 12.80 cm, mass 68.80 ± 13.90 kg). All participants completed 4 trials of the SET. Each trial consisted of six 20-s balance tests with eyes closed, under the following conditions: double-leg firm (DFi), single-leg firm (SFi), tandem firm (TFi), double-leg foam (DFo), single-leg foam (SFo), and tandem foam (TFo). Each trial was separated by a 5-min seated rest period. The dependent variable was sway velocity (deg/s), with lower values indicating better balance. Sway velocity was recorded for each of the 6 conditions as well as a composite score for each trial. Test-retest reliability was analyzed across 4 trials with intraclass correlation coefficients (ICCs). Practice effects analyzed with repeated measures analysis of variance, followed by Tukey post hoc comparisons for any significant main effects (P < .05). Sway-velocity reliability values were good to excellent: DFi (ICC = .88; 95%CI: .81, .92), SFi (ICC = .75; 95%CI: .61, .85), TFi (ICC = .84; 95%CI: .75, .90), DFo (ICC = .83; 95%CI: .74, .90), SFo (ICC = .82; 95%CI: .72, .89), TFo (ICC = .81; 95%CI: .69, .88), and composite score (ICC = .93; 95%CI: .88, .95). Significant practice effects (P < .05) were noted on the SFi, DFo, SFo, TFo conditions and composite scores. Our results suggest the SET has good to excellent reliability for the assessment of postural control in healthy adults. Due to the practice effects noted, a familiarization session is recommended (ie, all 6 conditions) before data are recorded. Future studies should evaluate injured patients to determine meaningful change scores during various injuries.