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.

Individual Baseline Balance Assessments in a Large Sample of Incoming NCAA Division I Athletes Using a Force Plate System.

BACKGROUND: Individualized baseline testing is resource and time intensive. The use of normative data to approximate changes after a suspected concussion is thus an appealing alternative. Yet, few peer-reviewed, large-sample studies are available from which to develop accurate normative averages of balance using force-plate technology. PURPOSE: This study sought to validate a normative dataset from the force-plate manufacturer and examine the magnitude and nature of sample variability. STUDY DESIGN: Cross-sectional. METHODS: Baseline balance and self-reported sex, sport, and concussion history were assessed in 533 prospective collegiate athletes (45% female) during pre-participation physical examinations. Balance was measured using four stances from the modified Clinical Test of Sensory Interaction and Balance and quantified as Sway Index Scores with the Biodex Biosway Portable Balance System. Group averages are contrasted to data from the force-plate manufacturer. Individual variability around these averages was visualized and analyzed by sex and sport. RESULTS: Male student athletes showed significantly more sway in the eyes open, soft stance condition than female athletes. These differences were maintained when concussion history was included as a covariate. Athletes, particularly male athletes, in the high versus low contact sport group showed significantly more sway in the eyes open, soft surface and the eyes closed, hard and soft surface stances. CONCLUSION: There was substantial individual variability that was partially explained by sex differences and sport differences. The development of normative averages for sway may benefit from consideration of sex and sport. Further studies should characterize other factors that influence baseline balance in collegiate athletes. LEVEL OF EVIDENCE: 2b.

Bigger Necks Are Not Enough: An Examination of Neck Circumference in Incoming College Athletes.

Neck circumference is quick and simple to measure and thus an attractive proxy of neck strength, a putative mechanism underlying risk of sport-related concussion (SRC). Research, however, is limited on the relationship of neck circumference to SRC. Our study examined differences in neck circumference based on sex, concussion history, concussions experienced subsequent to college entry, and participation in sports with high versus low risk for contact. Neck circumference was measured in incoming NCAA Division I athletes (N = 324) from a large northeastern university during athlete pre-participation physicals. Sex, sport team, and self-reported concussion history were obtained from retrospective pre-participation questionnaires and medical chart review. Concussion diagnoses during college were collected subsequent to neck measurements from medical chart review. Proportional neck circumference (normalized by body mass index) was computed. Each sport was categorized as involving high or low risk of contact (as a proxy of risk for injury). Sex differences in neck circumference and proportional neck circumference were assessed. Differences in neck circumference and proportional neck circumference were also characterized by contact risk and SRC history (with biological sex included as a covariate). Differences in neck circumference and proportional neck circumference were explored among those who did versus did not experience subsequent SRC diagnosis. Males had significantly larger neck circumference and proportional neck circumference than females. Neck circumference and proportional neck circumference were not related to SRC history or subsequent SRC. Neck circumference is a quick and simple measure; however, even when considered in proportion to body mass, it was unrelated to SRC. Future studies are needed to assess whether this is due to a lack of relationship between the neck and injury or limitations in circumference as a proxy measure of cervical spine characteristics and biomechanics.