Comparison of Concurrent and Same-Day Balance Measurement Approaches in a Large Sample of Uninjured Collegiate Athletes.

BACKGROUND: Measures of postural stability are useful in assisting the diagnosing and managing of athlete concussion. Error counting using the Balance Error Scoring System (BESS) is the clinical standard, but has notable limitations. New technologies offer the potential to increase precision and optimize testing protocols; however, whether these devices enhance clinical assessment remains unclear. PURPOSE: To examine the relationships between metrics of balance performance using different measurement systems in uninjured, healthy collegiate athletes. STUDY DESIGN: Cross-sectional. METHODS: Five hundred and thirty uninjured collegiate athletes were tested using the C3Logix app, which computes ellipsoid volume as a measure of postural stability during the six standard BESS conditions, while concurrently, errors were manually counted during each condition per standard BESS protocols. The association between concurrently measured ellipsoid volumes and error counts were examined with Spearman's correlations. From this sample, 177 participants also performed two double-leg conditions on the Biodex BioSway force plate system on the same day. This system computes Sway Index as a measure of postural stability. The association of ellipsoid volume (C3Logix) and Sway Index (Biodex) was examined with Spearman's correlations. Individual-level data were plotted to visually depict the relationships. RESULTS: C3Logix ellipsoid volume and concurrently recorded error counts were significantly correlated in five of the six BESS conditions (rs:.22-.62; p< 0.0001). C3Logix ellipsoid volume and Biodex Sway Index were significantly correlated in both conditions (rs=.22-.27, p< 0.004). However, substantial variability was shown in postural stability across all three measurement approaches. CONCLUSION: Modest correlation coefficients between simultaneous and same-day balance assessments in uninjured collegiate athletes suggest a need to further optimize clinical protocols for concussion diagnosis. LEVEL OF EVIDENCE: 2b.

Digital neuropsychological test performance in a large sample of uninjured collegiate athletes.

Digital neuropsychological test batteries are popular in college athletics; however, well-validated digital tests that are short and portable are needed to expand the feasibility of performing cognitive testing quickly, reliably, and outside standard clinical settings. This study assessed performance on digital versions of Trail Making Test (dTMT) and a modified Symbol Digit Modalities Test (dSDMT) in uninjured collegiate athletes (n = 537; 47% female) using the C3Logix baseline assessment module. Time to complete (dTMT) and the number of correct responses (dSDMT) were computed, transformed into z scores, and compared to age-matched normative data from analogous paper-and-pencil tests. Overall sample performance was compared to normative sample performance using Cohen's d. Sample averages on the dTMT, Part A, and dSDMT were similar to published norms; 97 and 92% of z scores fell within 2 standard deviations of normative means, respectively. The sample averaged faster completion times on dTMT, Part B than published norms, although 98% of z scores were within 2 standard deviations of the normative means. Brief, digitized tests may be useful in populations and testing environments when longer cognitive test batteries are impractical. Future studies should assess the ability of these tests to detect clinically relevant changes following a suspected head injury.

Considerations for Maximizing the Exercise "Drug" to Combat Insulin Resistance: Role of Nutrition, Sleep, and Alcohol.

Insulin resistance is a key etiological factor in promoting not only type 2 diabetes mellitus but also cardiovascular disease (CVD). Exercise is a first-line therapy for combating chronic disease by improving insulin action through, in part, reducing hepatic glucose production and lipolysis as well as increasing skeletal muscle glucose uptake and vasodilation. Just like a pharmaceutical agent, exercise can be viewed as a "drug" such that identifying an optimal prescription requires a determination of mode, intensity, and timing as well as consideration of how much exercise is done relative to sitting for prolonged periods (e.g., desk job at work). Furthermore, proximal nutrition (nutrient timing, carbohydrate intake, etc.), sleep (or lack thereof), as well as alcohol consumption are likely important considerations for enhancing adaptations to exercise. Thus, identifying the maximal exercise "drug" for reducing insulin resistance will require a multi-health behavior approach to optimize type 2 diabetes and CVD care.

Effects of Trial Duration on Intrasession Reliability of Single Leg Balance Testing on Stable and Unstable Surfaces.

CONTEXT: Single leg balance testing is a commonly used tool in sports medicine; however, there has been no consensus on trial duration needed to obtain reliable measures. OBJECTIVE: This investigation sought to determine the minimum trial duration required to obtain the highest intrasession single and average trial reliability for single leg balance testing on stable and unstable surfaces using dominant and nondominant limbs. DESIGN: Intrasession reliability. SETTING: Biomechanics laboratory. PARTICIPANTS: 70 healthy (35 men, 35 women), physically active young adults aged 22.8 ± 2.8 y divided into 3 subgroups (n = 10, 30, 30) across a 3-phase study. METHODS: 3 phases of single leg balance testing were performed. For phase 1, the duration of time each participant could maintain posture on each limb/surface were computed. Phase 2 considered performance for 6 cumulative time intervals (5s, 10s, 15s, 20s, 25s, 30s). Phase 3 served to solidify results of phase 2 by computing reliability of 15s trials. MAIN OUTCOME MEASURES: Overall stability index of the center of pressure and platform tilt. RESULTS: Intraclass correlation coefficients for phase 2 ranged from .74 (5s interval for nondominant limb on unstable surface) to .94 (20s interval for nondominant limb on stable surface). Phase 3 intraclass correlation coefficients ranged from .66 to .78 for single trial and .85 to .92 for 3 trial average with coefficients of variation ranging from 23.9% to 40.4% for single trial and 13.8% to 23.0% for 3 trial average. CONCLUSIONS: These results ultimately suggest 15s as the optimal trial duration to provide reliable measures while reducing compensatory event occurrence.

Intersession reliability of self-selected and narrow stance balance testing in older adults.

BACKGROUND: Despite the common practice of using force platforms to assess balance of older adults, few investigations have examined the reliability of postural screening tests in this population. AIM: We sought to determine the test-retest reliability of self-selected and narrow stance balance testing with eyes open and eyes closed in healthy older adults. METHODS: Thirty older adults (>65 years) completed 45 s trials of eyes open and eyes closed stability tests using self-selected and narrow stances on two separate days (1.9 ± .7 days). Average medial-lateral center of pressure velocity was computed. RESULTS: The ICC results ranged from .74 to .86, and no significant systematic changes (P < .05) occurred between the testing sessions for any of the tests. The standard error of measurement ranged from 15.9 to 23.6%. DISCUSSION: Reliability estimates were similar between the two stances and visual conditions assessed. Slightly higher coefficients were identified for the self-selected stances compared to the narrow stances under both visual conditions; however, there were negligible differences between the sessions. The within subject session-to-session variability provides a basis for further research to consider differences between fallers and non-fallers. CONCLUSION: Reliability for eyes open and closed balance testing using self-selected and narrow stances in older adults was established which should provide a foundation for the development of fall risk screening tests.