Objective: The purpose of this study was to explore the current reported, unreported, and potentially unrecognized concussion rates among collegiate student-athletes who have completed their collegiate athletic career. Design: Retrospective survey. Setting: College and University athletic training rooms. Participants: One hundred sixty-one collegiate student-athletes (56.5% women; aged 21.5 ± 1.3; 3.7 ± 1.0 years of collegiate athletic experience) from 10 institutions who had either completed their intercollegiate athletic eligibility or were no longer participating. Main Outcome Measures: The self-reported concussion rate, the unreported rate and reasons, and the potentially unrecognized concussion rate. Results: The self-reported concussion rate was 33.5% (54/161), and 22.2% (12) self-reported at least 3 concussions. The unreported rate was 11.8% (19/161), and the potentially unrecognized rate was 26.1% (42/161) with the most common unrecognized symptom being “knocked silly/seen stars” (23.6% [38/161]). Conclusions: Overall, 49.7% of all respondents (80/161) reported 1 acknowledged, unreported, or potential concussion. The unreported rate was lower than previous high school studies; however, the potentially unrecognized rate remains high and should be clinically concerning. These findings suggest educational interventions targeting collegiate student-athletes should remain and continue to focus on identifying concussion symptoms and dispelling the common misconception that “bell ringers” and “dings” are not concussions.

Prior studies suggest that concussion may lead to an increased risk of a subsequent time-loss sport-related injury, but the mechanisms responsible are unknown. We measured the symptom and dual-task gait outcomes for athletes initially post-concussion and after clinical recovery. Participants then self-reported any additional injuries incurred in the year after their concussion. Forty-two athletes (52% female, mean age=16.8±3.2 years) completed the study. They underwent a dual-task gait evaluation and symptom inventory within 21 days post-concussion, and again after they were deemed clinically recovered. Approximately one year later, participants documented if they had sustained any subsequent sport-related injuries. Repeated measures ANOVAs were used to evaluate changes in dual-task gait and symptoms across time and between groups. A significant group*time interaction (p=0.02) indicated that the group who went on to sustain a subsequent time-loss injury after returning to sports (n=15) demonstrated significant average walking speed dual-task cost worsening across time (-17.9±9.1% vs. -25.1±12.5%; p=0.007). In contrast, the group who did not sustain an additional injury walked with consistent dual-task cost values across time (-25.2±9.2% vs. -24.6±8.4%; p=0.76). Symptoms improved for all participants (main effect of time p<0.001; PCSS= 25.0±16.9 vs. 2.8±7.5; p<0.001), but did not differ between groups (p=0.77). Significant dual-task gait cost worsening throughout concussion recovery was associated with time-loss injuries during sports in the year after a concussion. These findings indicate that worsening ability to execute a concurrent gait and cognitive task may relate to the risk of incurring an injury during sports after clinical concussion recovery.

Concussion, or mild traumatic brain injury, incidence rates have reached epidemic levels and impaired postural control is a cardinal symptom. The purpose of this review is to provide an overview of the linear and non-linear assessments of post-concussion postural control. The current acute evaluation for concussion utilizes the subjective balance error scoring system (BESS) to assess postural control. While the sensitivity of the overall test battery is high, the sensitivity of the BESS is unacceptably low and, with repeat administration, is unable to accurately identify recovery. Sophisticated measures of postural control, utilizing traditional linear assessments, have identified impairments in postural control well beyond BESS recovery. Both assessments of quiet stance and gait have identified lingering impairments for at least 1 month post-concussion. Recently, the application of non-linear metrics to concussion recovery have begun to receive limited attention with the most commonly utilized metric being approximate entropy (ApEn). ApEn, most commonly in the medial-lateral plane, has successfully identified impaired postural control in the acute post-concussion timeframe even when linear assessments of instrumented measures are equivalent to healthy pre-injury values; unfortunately these studies have not gone beyond the acute phase of recovery. One study has identified lingering deficits in postural control, utilizing Shannon and Renyi entropy metrics, which persist at least through clinical recovery and return to participation. Finally, limited evidence from two studies suggest that individuals with a previous history of a single concussion, even months or years prior, may display altered ApEn metrics. Overall, non-linear metrics provide a fertile area for future study to further the understanding of postural control impairments acutely post-concussion and address the current challenge of sensitive identification of recovery.

Context: The National Collegiate Athletic Association (NCAA) has published concussion-management practice guidelines consistent with recent position and consensus statements. Whereas NCAA Division I athletic trainers appear highly compliant, little is known about the concussion-management practice patterns of athletic trainers at smaller institutions where staffing and resources may be limited. Objective: To descriptively define the concussion-management practice patterns of NCAA Division II and III athletic trainers. Design: Cross-sectional study. Setting: Web-based questionnaire. Patients or Other Participants: A total of 755 respondents (response rate = 40.2%) from NCAA Division II and Division III institutions. Main Outcome Measure(s): The primary outcome measures were the rate of multifaceted concussion-assessment techniques, defined as 3 or more assessments; the specific practice patterns of each assessment battery; and tests used during a clinical examination. Results: Most respondents indicated using a multifaceted assessment during acute assessment (Division II = 76.9%, n = 473; Division III = 76.0%, n = 467) and determination of recovery (Division II = 65.0%, n = 194; Division III = 63.1%, n = 288) but not at baseline (Division II = 43.1%, n = 122; Division III = 41.0%, n = 176). Typically, when a postconcussion assessment was initiated, testing occurred daily until baseline values were achieved, and most respondents (80.6% [244/278]) reported using a graded exercise protocol before return to participation. Conclusions: We found limited use of the multifaceted assessment battery at baseline but higher rates at both acute assessment and return-to-participation time points. A primary reason cited for not using test-battery components was a lack of staffing or funding for the assessments. We observed limited use of neuropsychologists to interpret neuropsychological testing. Otherwise, most respondents reported concussion-management protocols consistent with recommendations, including a high level of use of objective measures and incorporation of a progressive return-to-participation protocol.

Purpose: The purpose was to evaluate tandem gait (TG), Balance Error Scoring System (BESS), and modified Balance Error Scoring System (mBESS) performance acutely after concussion in collegiate student-athletes. In addition, we sought to evaluate the psychometric properties of TG, including minimal detectable change (MDC), sensitivity, and specificity.Methods: Seventy-six National Collegiate Athletic Association student-athletes performed TG and BESS tests: 38 acutely after concussion and 38 controls. Participants were tested at baseline (time 1) and again acutely after concussion, or the following year for controls (time 2). Ten controls, tested simultaneously by two researchers, established a TG interrater minimal detectable change. A 2 × 2 mixed-design ANOVA compared each outcome variable. An receiver operating characteristic curve analysis was used to evaluate sensitivity, specificity, and area under the curve (AUC).Result: There was a significant interaction (F= 8.757,P= 0.004) for TG whereby the concussion group was slower after concussion (10.59 ± 1.53 vs 11.80 ± 2.67 s), whereas there was no difference for controls (10.13 ± 1.72 vs 9.93 ± 1.85 s). There was no significant interaction for BESS (F= 0.235,P= 0.630) or mBESS (F= 0.007,P= 0.935). TG had a sensitivity of 0.632, a specificity of 0.605, and an AUC of 0.704. BESS had a sensitivity of 0.447, a specificity of 0.500, and an AUC of 0.508. mBESS had a sensitivity of 0.474, a specificity of 0.632, and an AUC of 0.535.Conclusions: Participants completed TG significantly slower after concussion, whereas no change across time was detected for controls. In contrast, BESS and mBESS performances were similar at both testing times in both groups. Our AUC analysis was acceptable for TG, but a failure for both BESS and mBESS; thus, TG may be a useful alternative for clinicians conducting postconcussion postural control assessments.