Quantifying core stability: a technical report.

In prior research, we used 4 stability platform tests as a measurement of core stability and found that scores on the third and fourth days of testing were essentially the same for each of the 4 tests. Lafayette Instrument Co. subsequently made us a prototype stability platform to enhance this research. The purpose of the present research was to determine the effect of changes in (1) equipment and (2) number of test administrations on test reliability. We also increased the number of test administrations on each day from 5 to 10 but only used the quadruped arm raise test. The subjects were 25 university students; each was tested on 10 trials of 30-seconds duration on 4 different days to enable us to study the learning effect. All 10 trials for the first day, as well as the first trial on the 3 subsequent days of testing, were used as practice trials. Trials 2 to 6 on testing days 2 to 4 were chosen for the data analysis. With 5 trials, the maximum score attainable was 150 seconds.; the means were 125 for day 2 and 132 for both days 3 and 4. Internal consistency intraclass reliability coefficients based on a 1-way analysis of variance model and a criterion score, which was the sum or mean of trials 2 to 6 for days 2 to 4, were 0.89, 0.95, and 0.92, respectively. Stability reliabilities were 0.76 and 0.92 for day 2 versus day 3 and day 3 versus day 4, respectively. Although we had hoped to show that only 2 days of testing would be required in future research, because of learning effect, 3 will be needed.

The reliability of the modified Balance Error Scoring System.

OBJECTIVE: Study 1 investigated the intraclass reliability and percent variance associated with each component within the traditional Balance Error Scoring System (BESS) protocol. Study 2 investigated the reliability of subsequent modifications of the BESS. DESIGN: Prospective cross-sectional examination of the traditional and modified BESS protocols. SETTING: Schools participating in Georgia High School Athletics Association. INTERVENTION: The modified BESS consisted of 2 surfaces (firm and foam) and 2 stances (single-leg and tandem-leg stance) repeated for a total of three 20-second trials. PARTICIPANTS: Participants consisted of 2 independent samples of high school athletes aged 13 to 19 years. MAIN OUTCOME MEASURES: Percent variance for each condition of the BESS was obtained using GENOVA 3.1. An intraclass reliability coefficient and repeated measures analysis of variance were calculated using SPSS 13.0. RESULTS: Study 1 obtained an intraclass correlation coefficient (r = 0.60) with stance accounting for 55% of the total variance. Removing the double-leg stance increased the intraclass correlation coefficient (r = 0.71). Study 2 found a statistically significant difference between trials 1 and 2 (F(1.65,286) = 4.890, P = 0.013) and intraclass reliability coefficient of r = 0.88 for 3 trials of 4 conditions. CONCLUSIONS: The variance associated with the double-leg stance was very small, and when removed, the intraclass reliability coefficient of the BESS increased. Removal of the double-leg stance and addition of 3 trials of 4 conditions provided an easily administered, cost-effective, time-efficient tool that provides reliable objective information for clinicians to base clinical decisions upon.

Test-retest reliability of computerized concussion assessment programs.

CONTEXT: Computer-based neurocognitive assessment programs commonly are used to assist in concussion diagnosis and management. These tests have been adopted readily by many clinicians based on existing test-retest reliability data provided by test developers. OBJECTIVE: To examine the test-retest reliability of 3 commercially available computer-based neurocognitive assessments using clinically relevant time frames. DESIGN: Repeated-measures design. SETTING: Research laboratory. PATIENTS OR OTHER PARTICIPANTS: 118 healthy student volunteers. MAIN OUTCOME MEASURE(S): The participants completed the ImPACT, Concussion Sentinel, and Headminder Concussion Resolution Index tests on 3 days: baseline, day 45, and day 50. Each participant also completed the Green Memory and Concentration Test to evaluate effort. Intraclass correlation coefficients were calculated for all output scores generated by each computer program as an estimate of test-retest reliability. RESULTS: The intraclass correlation coefficient estimates from baseline to day 45 assessments ranged from .15 to .39 on the ImPACT, .23 to .65 on the Concussion Sentinel, and .15 to .66 on the Concussion Resolution Index. The intraclass correlation coefficient estimates from the day 45 to day 50 assessments ranged from .39 to .61 on the ImPACT, .39 to .66 on the Concussion Sentinel, and .03 to .66 on the Concussion Resolution Index. All participants demonstrated high levels of effort on all days of testing, according to Memory and Concentration Test interpretive guidelines. CONCLUSIONS: Three contemporary computer-based concussion assessment programs evidenced low to moderate test-retest reliability coefficients. Our findings do not appear to be due to suboptimal effort or other factors related to poor test performance, because persons identified by individual programs as having poor baseline data were excluded from the analyses. The neurocognitive evaluation should continue to be part of a multifaceted concussion assessment program, with priority given to those scores showing the highest reliability.

Measuring core stability.

In this study, a 4-item battery of core stability (CS) tests modeled on core stabilization activities used in training and rehabilitation research was developed, and a measurement schedule was established to maximize internal consistency and stability reliabilities. Specifically, we found that 4 test administrations on each of 4 days produced intraclass correlation coefficients that in most instances exceeded 0.90 and stability reliability coefficients on the third and fourth days of testing that exceeded 0.90 for 2 of the tests and 0.80 for the other 2. Thus, it is recommended that in future research, examiners administer the battery for at least 3 days and consider the data collected on day 3 as the best estimate of participant CS.