Factors and expectations influencing concussion disclosure within NCAA Division I athletes: A mixed methodological approach.

BACKGROUND: Participation in sports is associated with many benefits to all aspects of health; however, it also comes with the risk of injury, particularly concussions. Self-disclosure and care seeking following a concussion are especially important because of the lack of outwardly visible signs and/or symptoms. Although recent research has explored factors affecting concussion disclosure, use of isolated methodologies limits the ability to contextualize how disclosure or nondisclosure occurs. Therefore, the purpose of this study was to describe the factors and expectations of National Collegiate Athletic Association (NCAA) athletes that may influence concussion disclosure. METHODS: This mixed-methods convergent parallel research study included 25 NCAA Division I athletes representing 13 sports, all of whom completed a concussion-education session with pre-/post-test surveys and a semistructured interview. Eligible athletes were at least 18 years old and on an NCAA roster. The surveys focused on previous concussion-related disclosure behaviors, knowledge, attitudes, beliefs, norms, and intentions about disclosing concussion. Interviews focused on the athletes' experiences related to concussion disclosure. Survey data were analyzed using descriptive statistics and Mann-Whitney U tests. Interviews were analyzed using a Consensual Qualitative Research tradition. RESULTS: Participants had good concussion knowledge (median = 46.0), positive attitudes (median = 38.0), strong beliefs (median = 13.0), and strong intentions to disclose concussion symptoms (median = 7.0). None of the constructs differed by participants' gender. Although quantitative findings were mostly positive, interview data highlighted factors that may explain why some participants are successful in disclosing concussions and why others may find disclosure difficult. Educational efforts, sport culture, and medical professional presence were the primary facilitators discussed by participants. Stigma, pressure, and a lack of team support were perceived as disclosure barriers. CONCLUSION: The context in which concussion disclosure occurs or does not occur is vital to the success of educational interventions. Interventions must prioritize stakeholder- and team-based perspectives on concussion to establish a network supportive to disclosure.

Influence of Graft Type on Lower Extremity Functional Test Performance and Failure Rate After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Both autografts and allografts are used to reconstruct the anterior cruciate ligament (ACL) after injury; however, it is unclear whether graft source affects lower extremity functional test performance or failure rate in an active military population. OBJECTIVE: To compare lower extremity functional test performance and graft failure rates between ACL grafts [allograft, hamstring, bone-patellar tendon-bone (BTB)]. STUDY DESIGN: Cross-sectional. LEVEL OF EVIDENCE: Level 2. METHODS: Ninety-eight cadets entering a US Service Academy with a history of unilateral ACL reconstruction (ACLR) agreed to participate. Before basic training, participants completed 4 lower extremity functional tests. Active injury surveillance was conducted within the study cohort to identify all subsequent graft failures. RESULTS: Cadets with hamstring autografts outperformed the BTB and allograft groups on the Lower Quarter Y-Balance Test-Posteromedial direction and single-leg hop test, respectively. No differences were detected by graft type for the other functional tests. The incidence of subsequent ipsilateral graft failures in patients with autograft was 8.11%. No failures were observed in the allograft group during the follow-up period. After controlling for sex, joint hypermobility, and time since injury and surgery, the risk of graft failure was 9.8 times higher for patients with a hamstring autograft than with a BTB (P = 0.045). CONCLUSION: After ACLR, graft type appears to influence some single-limb measures of lower extremity function and the risk of subsequent failure. Hamstring autografts demonstrated better functional performance but increased risk of graft failure. CLINICAL RELEVANCE: Surgeons need to weigh the pros and cons of all graft options in relation to the patient's lifestyle. Regardless of graft type, individuals with an ACLR may require additional rehabilitation to regain neuromuscular control during dynamic single-limb tasks and mitigate graft failure.

Association Between Landing Error Scoring System (LESS) Items and the Incidence Rate of Lower Extremity Stress Fracture.

Background: Lower extremity stress fracture injuries are a major cause of morbidity in physically active populations. The ability to screen for modifiable risk factors associated with injury is critical in developing injury-prevention programs. Purpose: To determine if baseline Landing Error Scoring System (LESS) scores are associated with the incidence rate of lower extremity stress fracture. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 1772 participants with no history of lower extremity stress fracture were included. At preinjury baseline, the authors conducted a lower extremity movement assessment during a jump-landing task using the LESS. Incident lower extremity stress fractures were identified during a 4-year follow-up period. Potential incident cases were reviewed by 2 sports medicine fellowship-trained orthopaedic surgeons blinded to baseline LESS data. Univariate and multivariable Poisson regression models were used to estimate the association between baseline total LESS scores, individual LESS items, and the incidence rate ratio (IRR) of lower extremity stress fracture. Results: A total of 94 incident lower extremity stress fractures were documented, for a 5.3% (95% CI, 4.3%-6.5%) cumulative incidence. The overall LESS score was associated with the incidence rate of lower extremity stress fracture. For every additional movement error documented at baseline, there was a 15% increase in the incidence rate of lower extremity stress fracture (IRR, 1.15 [95% CI, 1.02-1.31]; P = .025). In univariate analyses, ankle flexion, stance width, asymmetrical landing, and trunk flexion at initial contact, in addition to overall impression, were associated with the incidence rate of stress fracture. After controlling for sex and year of entry into the study cohort, participants who consistently landed flat-footed or heel-to-toe were 2.33 times (95% CI, 1.36-3.97; P = .002) more likely to sustain a lower extremity stress fracture. Similarly, participants who consistently demonstrated asymmetric landing at initial contact were 2.53 times (95% CI, 1.34-4.74; P = .004) more likely to sustain a stress fracture. Conclusion: Components of the LESS may be associated with increased lower extremity stress fracture risk and may be helpful in efficiently assessing high-risk lower extremity biomechanics in large groups.

Automated Landing Error Scoring System Performance and the Risk of Bone Stress Injury in Military Trainees.

CONTEXT: Lower extremity bone stress injuries (BSIs) place a significant burden on the health and readiness of the US Armed Forces. OBJECTIVE: To determine if preinjury baseline performance on an expanded and automated 22-item version of the Landing Error Scoring System (LESS-22) was associated with the incidence of BSIs in a military training population. DESIGN: Prospective cohort study. SETTING: US Military Academy at West Point, NY. PATIENTS OR OTHER PARTICIPANTS: A total of 2235 incoming cadets (510 females [22.8%]). MAIN OUTCOME MEASURE(S): Multivariable Poisson regression models were used to produce adjusted incidence rate ratios (IRRs) to quantify the association between preinjury LESS scores and BSI incidence rate during follow-up and were adjusted for pertinent risk factors. Risk factors were included as covariates in the final model if the 95% CI for the crude IRR did not contain 1.00. RESULTS: A total of 54 BSIs occurred during the study period, resulting in an overall incidence rate of 0.07 BSI per 1000 person-days (95% CI = 0.05, 0.09). The mean number of exposure days was 345.4 ± 61.12 (range = 3-368 days). The final model was adjusted for sex and body mass index and yielded an adjusted IRR for a LESS-22 score of 1.06 (95% CI = 1.002, 1.13; P = .04), indicating that each additional LESS error documented at baseline was associated with a 6.0% increase in the incidence rate of BSI during the follow-up period. In addition, 6 individual LESS-22 items, including 2 newly added items, were significantly associated with the BSI incidence. CONCLUSIONS: We provided evidence that performance on the expanded and automated version of the LESS was associated with the BSI incidence in a military training population. The automated LESS-22 may be a scalable solution for screening military training populations for BSI risk.

Reference Values for the Headache Impact Test-6 Questionnaire.

OBJECTIVE: To determine reference values for the Headache Impact Test-6 (HIT-6) in a young, physically active cohort and to examine the influence of sex, concussion history, headache history, and competitive sport level on HIT-6 scores. DESIGN: Cross-sectional. SETTING: United States Service Academy. PARTICIPANTS: United States Service Academy cadets (N=2678) completed an HIT-6 questionnaire as part of their annual concussion baseline assessment. Cadets with a recent concussion were excluded from baseline testing. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Reference values were calculated and stratified by sex, concussion history, headache history, and competitive sport level. Mann-Whitney U and Kruskal-Wallis tests were used to examine the effect of sex, concussion history, headache history, and competitive sport level on HIT-6 scores (P<.05). RESULTS: Of the 3599 cadets baselined, 2687 cadets (23% female) agreed to participate in the study and completed the HIT-6. Female participants reported significantly worse HIT-6 scores compared with male participants both with (P<.001) and without (P<.001) a concussion history. In both sexes, participants with a headache history reported worse scores than those with no headache/concussion history and a concussion history (all P<.005). Female cadets who participated in intramural athletics reported worse HIT-6 scores at baseline than female intercollegiate athletes (P=.003). CONCLUSIONS: This is the first study to stratify HIT-6 data by sex, concussion history, headache history, and sport level in a collegiate population at risk for concussions. Sex and headache history appear to influence HIT-6 scores and should be given special consideration when interpreting health-related quality of life deficits due to headache.

Differences in Lower Extremity Movement Quality by Level of Sport Specialization in Cadets Entering a United States Service Academy.

BACKGROUND: Sport specialization in youth athletes is associated with increased risk for musculoskeletal injury; however, little is known about whether sport specialization is associated with lower extremity movement quality. The purpose of this study was to examine differences in lower extremity movement quality by level of sport specialization in US Service Academy cadets. HYPOTHESIS: Cadets who report an increased level of sport specialization would have a lower level of movement quality than those who are less specialized. STUDY DESIGN: Cross-sectional analysis from an ongoing prospective cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: Cadets completed the Landing Error Scoring System (LESS) and a baseline questionnaire evaluating level of sport specialization during high school. Data were analyzed using separate 1-way analysis of variance models. RESULTS: Among all participants (n = 1950), 1045 (53.6%) reported low sport specialization, 600 (30.8%) reported moderate sport specialization, and 305 (15.6%) reported high sport specialization at the time of data collection during the first week. Ages ranged from 17 to 23 years. Men (1491) and women (459) reported comparable specialization levels (P = 0.45). There were no statistically significant differences in lower extremity movement quality by level of specialization for all subjects combined (P = 0.15) or when only men were included in the analyses (P = 0.69). However, there were statistically significant differences in movement quality by level of specialization in women (P = 0.02). Moderately specialized women had the best movement quality (mean, 4.63; SD, 2.21) followed by those with high specialization (mean, 4.90; SD, 2.08) and those with low levels of specialization (mean, 5.23; SD, 2.07). CONCLUSION: Women reporting moderate sport specialization had improved movement quality and significantly better LESS scores compared to those with high/low specialization. CLINICAL RELEVANCE: Athletes, especially women, should be encouraged to avoid early sport specialization to optimize movement quality, which may affect injury risk.

Test-Retest Reliability of Concussion Baseline Assessments in United States Service Academy Cadets: A Report from the National Collegiate Athletic Association (NCAA)-Department of Defense (DoD) CARE Consortium.

OBJECTIVE: In response to advancing clinical practice guidelines regarding concussion management, service members, like athletes, complete a baseline assessment prior to participating in high-risk activities. While several studies have established test stability in athletes, no investigation to date has examined the stability of baseline assessment scores in military cadets. The objective of this study was to assess the test-retest reliability of a baseline concussion test battery in cadets at U.S. Service Academies. METHODS: All cadets participating in the Concussion Assessment, Research, and Education (CARE) Consortium investigation completed a standard baseline battery that included memory, balance, symptom, and neurocognitive assessments. Annual baseline testing was completed during the first 3 years of the study. A two-way mixed-model analysis of variance (intraclass correlation coefficent (ICC)3,1) and Kappa statistics were used to assess the stability of the metrics at 1-year and 2-year time intervals. RESULTS: ICC values for the 1-year test interval ranged from 0.28 to 0.67 and from 0.15 to 0.57 for the 2-year interval. Kappa values ranged from 0.16 to 0.21 for the 1-year interval and from 0.29 to 0.31 for the 2-year test interval. Across all measures, the observed effects were small, ranging from 0.01 to 0.44. CONCLUSIONS: This investigation noted less than optimal reliability for the most common concussion baseline assessments. While none of the assessments met or exceeded the accepted clinical threshold, the effect sizes were relatively small suggesting an overlap in performance from year-to-year. As such, baseline assessments beyond the initial evaluation in cadets are not essential but could aid concussion diagnosis.

Perceived social norms and concussion-disclosure behaviours among first-year NCAA student-athletes: implications for concussion prevention and education.

Timely disclosure and identification of concussion symptoms are essential to proper care. Perceived social norms are a potential driving factor in many health-related decisions. The study purpose was to describe concussion disclosure behaviours and identify the association between perceived social norms and these disclosure behaviours. First-year student-athletes (n = 391) at two NCAA institutions completed a cross-sectional survey about concussion disclosure and disclosure determinants. Log-binomial regression models identified factors associated with concussion disclosure behaviour prevalence for: higher intention to disclose symptoms, disclosed all at time of injury, eventually disclosed all, and never participated with concussion symptoms. More favourable perceived social norms were associated with higher prevalence of intention to disclose (PR = 1.34; 95%CI: 1.18, 1.53) and higher prevalence of never participating in sports with concussion symptoms (PR = 1.50; 95%CI: 1.07, 2.10). Clinicians, coaches, sports administrators, and healthcare practitioners should be mindful of the need to create supportive social environments to improve concussion symptom disclosure.

Trunk and Lower Extremity Movement Patterns, Stress Fracture Risk Factors, and Biomarkers of Bone Turnover in Military Trainees.

CONTEXT: Military service members commonly sustain lower extremity stress fractures (SFx). How SFx risk factors influence bone metabolism is unknown. Understanding how SFx risk factors influence bone metabolism may help to optimize risk-mitigation strategies. OBJECTIVE: To determine how SFx risk factors influence bone metabolism. DESIGN: Cross-sectional study. SETTING: Military service academy. PATIENTS OR OTHER PARTICIPANTS: Forty-five men (agepre = 18.56 ± 1.39 years, heightpre = 176.95 ± 7.29 cm, masspre = 77.20 ± 9.40 kg; body mass indexpre = 24.68 ± 2.87) who completed Cadet Basic Training (CBT). Individuals with neurologic or metabolic disorders were excluded. INTERVENTION(S): We assessed SFx risk factors (independent variables) with (1) the Landing Error Scoring System (LESS), (2) self-reported injury and physical activity questionnaires, and (3) physical fitness tests. We assessed bone biomarkers (dependent variables; procollagen type I amino-terminal propeptide [PINP] and cross-linked collagen telopeptide [CTx-1]) via serum. MAIN OUTCOME MEASURE(S): A markerless motion-capture system was used to analyze trunk and lower extremity biomechanics via the LESS. Serum samples were collected post-CBT; enzyme-linked immunosorbent assays determined PINP and CTx-1 concentrations, and PINP : CTx-1 ratios were calculated. Linear regression models demonstrated associations between SFx risk factors and PINP and CTx-1 concentrations and PINP : CTx-1 ratio. Biomarker concentration mean differences with 95% confidence intervals were calculated. Significance was set a priori using α ≤ .10 for simple and α ≤ .05 for multiple regression analyses. RESULTS: The multiple regression models incorporating LESS and SFx risk factor data predicted the PINP concentration (R2 = 0.47, P = .02) and PINP : CTx-1 ratio (R2 = 0.66, P = .01). The PINP concentration was increased by foot internal rotation, trunk flexion, CBT injury, sit-up score, and pre- to post-CBT mass changes. The CTx-1 concentration was increased by heel-to-toe landing and post-CBT mass. The PINP : CTx-1 ratio was increased by foot internal rotation, lower extremity sagittal-plane displacement (inversely), CBT injury, sit-up score, and pre- to post-CBT mass changes. CONCLUSIONS: Stress fracture risk factors accounted for 66% of the PINP : CTx-1 ratio variability, a potential surrogate for bone health. Our findings provide insight into how SFx risk factors influence bone health. This information can help guide SFx risk-mitigation strategies.

Factors Associated With Delayed Concussion Reporting by United States Service Academy Cadets.

CONTEXT: Approximately half of individuals who sustain a concussion do not immediately report their injuries. Motivators for not reporting include thinking the suspected concussion was not a serious injury and wanting to continue participating in activity. Additionally, military personnel have concerns about how concussions may affect their careers. However, delayed reporting can prolong neurobehavioral recovery. Understanding the frequency of delayed reporting and contributing factors will aid in identifying individuals who may be more likely to delay reporting. OBJECTIVE: To describe the frequency of delayed concussion reporting by service academy cadets and determine if sex, injury setting, sport level, or medical history is capable of predicting delayed reporting. DESIGN: Cohort study. SETTING: Service academies. PATIENTS OR OTHER PARTICIPANTS: A total of 316 patients with concussions were observed from January 2014 to August 2016. MAIN OUTCOME MEASURE(S): All cadets completed an annual concussion baseline collection of demographic, medical history, and sports participation information. Delayed concussion reporting served as the outcome variable. Predictor variables were sex, injury setting, and sport level, as well as concussion, headache, and learning disorder history. Frequencies were calculated to describe the proportion of participants who delayed reporting. Univariable and multivariable logistic regression models were used to assess if the predictor variables were associated with delayed concussion reporting. Odds ratios (ORs) and 95% confidence intervals were calculated for all variables included in the final model. RESULTS: Of the patients with concussion, 51% were classified as delayed reporting. In univariable models, females (OR = 1.70) and National Collegiate Athletic Association cadet-athletes (OR = 1.98) were more likely to delay reporting than males and intramural cadet-athletes, respectively. The multivariable model yielded similar findings. CONCLUSIONS: Roughly half of the cadets who sustained a concussion failed to immediately report their injury. Specifically, our data suggested that female cadets, cadets injured outside of competition, and highly competitive cadet-athletes were almost twice as likely to delay reporting as others.

Concussion-Recovery Trajectories Among Tactical Athletes: Results From the CARE Consortium.

CONTEXT: Assessments of the duration of concussion recovery have primarily been limited to sport-related concussions and male contact sports. Furthermore, whereas durations of symptoms and return-to-activity (RTA) protocols encompass total recovery, the trajectory of each duration has not been examined separately. OBJECTIVE: To identify individual (eg, demographics, medical history), initial concussion injury (eg, symptoms), and external (eg, site) factors associated with symptom duration and RTA-protocol duration after concussion. DESIGN: Cohort study. SETTING: Three US military service academies. PATIENTS OR OTHER PARTICIPANTS: A total of 10 604 cadets at participating US military service academies enrolled in the study and completed a baseline evaluation and up to 5 postinjury evaluations. A total of 726 cadets (451 men, 275 women) sustained concussions during the study period. MAIN OUTCOME MEASURE(S): Number of days from injury (1) until the participant became asymptomatic and (2) to complete the RTA protocol. RESULTS: Varsity athlete cadets took less time than nonvarsity cadets to become asymptomatic (hazard ratio [HR] = 1.75, 95% confidence interval = 1.38, 2.23). Cadets who reported less symptom severity on the Sport Concussion Assessment Tool, third edition (SCAT3), within 48 hours of concussion had 1.45 to 3.77 times shorter symptom-recovery durations than those with more symptom severity. Similar to symptom duration, varsity status was associated with a shorter RTA-protocol duration (HR = 1.74, 95% confidence interval = 1.34, 2.25), and less symptom severity on the SCAT3 was associated with a shorter RTA-protocol duration (HR range = 1.31 to 1.47). The academy that the cadet attended was associated with the RTA-protocol duration (P < .05). CONCLUSIONS: The initial total number of symptoms reported and varsity athlete status were strongly associated with symptom and RTA-protocol durations. These findings suggested that external (varsity status and academy) and injury (symptom burden) factors influenced the time until RTA.

Influence of Concussion Education Exposure on Concussion-Related Educational Targets and Self-Reported Concussion Disclosure among First-Year Service Academy Cadets.

INTRODUCTION: Concussion disclosure is often essential for military personnel to receive appropriate care following concussive injury. Concussion-related education and training may play a role in improving disclosure and recognition among peers, allowing for more timely concussion identification and treatment. The objectives of this study were to: (1) describe concussion education exposure among first-year service academy cadets and (2) examine the association between exposure to concussion education sources (multiple vs. only one) and concussion-related knowledge, attitudes, perceived social norms, intention to disclose symptoms, and disclosure behaviors. MATERIALS AND METHODS: First-year service academy cadets completed a cross-sectional survey to assess perceptions of concussion disclosure during preseason concussion baseline testing sessions. Associations between key cadet characteristics and exposure to multiple concussion education sources were examined using odds ratios and 95% confidence intervals. Linear regression was used to model the continuous measures of concussion-related knowledge, attitudes, and perceived social norms. Log-binomial regression was used to model the categorical outcomes of high perceived control over concussion disclosure (higher vs. lower), intention to disclose (higher vs. lower), and disclosure of all possible concussive events at the time of injury (yes vs. no). The primary predictor for all models was exposure to multiple sources of concussion education (video, coach, medical professional, or other) vs. exposure to only one educational source. All models were adjusted for gender, high school contact sport participation, and previous concussion history. RESULTS: Of the 972 first-year cadets (85% response; age = 18.4 ± 0.9 years; 21.7% female, 29.0% NCAA student-athlete), 695 (71.5%) reported receiving some type of previous concussion education and 229 (23.6%) reported a previous concussion history (206/229 reported the actual number they experienced). Of those reporting previous concussion-related education (n = 695), 542 (78.0%) watched a video, 514 (74.0%) talked with a coach about concussion, 433 (62.3%) talked with a medical professional, and 61 (8.8%) reported other sources of education ranging from anatomy teachers to brochures. Overall, 527 (75.8%) reported receiving more than one source of concussion education. Having played a contact sport in high school and having a history of concussion were associated with having multiple concussion education exposures. Being female was associated with lower odds of multiple exposures. Exposure to multiple sources of concussion education was not associated with knowledge, attitudes, perceived norms, or higher intention to disclose concussion symptoms. However, among those with a concussion history, exposure to multiple sources of concussion education was associated with a nearly 40% higher prevalence of disclosing all concussions at the time of injury compared to only one source of educational exposure (67.1% vs. 48.3%; prevalence ratio = 1.4; 95% confidence interval: 0.9, 2.1). Thus, although multiple sources of education may not influence intermediate variables of knowledge, attitudes, perceived norms and intentions, exposure to multiple sources of concussion education may influence actual decision-making around concussion disclosure among first-year service academy cadets. CONCLUSION: These data suggest disparities in concussion education exposure that can be addressed in first-year cadets. Additionally, findings support the importance and use of multiple sources of concussion education in improving cadet's concussion-related decision-making.

The Influence of Self-Reported Tobacco Use on Baseline Concussion Assessments.

INTRODUCTION: Baseline symptom, balance, and neurocognitive scores have become an integral piece of the concussion management process. Factors such as sleep, learning disorders, fitness level, and sex have been linked to differences in performance on baseline assessments; however, it is unclear how tobacco use may affect these scores. The objective of this study was to compare baseline concussion assessment scores between service academy cadets who use and do not use tobacco. METHODS: Cadets completed a standard battery of concussion baseline assessments per standard of care and were classified into two groups: tobacco users (n = 1,232) and nonusers (n = 5,922). Dependent variables included scores on the Balance Error Scoring System, Standardized Assessment of Concussion, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Brief Symptom Inventory-18, and Brief Sensation Seeking Scale (BSSS). Separate Mann-Whitney U-tests were used to compare all baseline assessment scores between groups with an adjusted P-value < 0.004. RESULTS: Cadets that used tobacco performed significantly worse on the impulse control (P < 0.001) section of the ImPACT, reported greater ImPACT symptom severity scores (P < 0.001), and were more likely to take risks as measured by the BSSS (P < 0.001). No differences were detected for Balance Error Scoring System, Standardized Assessment of Concussion, Brief Symptom Inventory-18, and Sport Concussion Assessment Tool-3 symptom scores, verbal memory, visual memory, visual-motor speed, or reaction time on the ImPACT (P > 0.004). CONCLUSIONS: Tobacco users performed significantly worse than tobacco nonusers on the impulse control section of the ImPACT, reported greater symptom severity scores on the ImPACT, and were more likely to take risks as measured by the BSSS. Despite statistical significance, these results should be interpreted with caution, as the overall effect sizes were very small. Future research should examine the influence of tobacco use on recovery post-concussion.

Increased Glenoid Retroversion Is Associated With Increased Rotator Cuff Strength in the Shoulder.

BACKGROUND: The rotator cuff muscles are critical secondary stabilizers in the shoulder. Increased glenoid retroversion and rotator cuff strength have been associated with the risk of posterior shoulder instability; however, the effect of increased glenoid retroversion on rotator cuff strength remains unclear. PURPOSE/HYPOTHESIS: The purpose was to examine the association between glenoid version and rotator cuff strength in the shoulder in a young and healthy population with no history of shoulder instability. The hypothesis was that increased glenoid retroversion would be associated with increases in rotator cuff muscle strength. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A prospective cohort study was conducted over a 4-year period within a high-risk population to identify the risk factors for shoulder instability. Analyzed participants included 574 freshmen entering a United States service academy. Baseline data collected upon entry into the study included magnetic resonance imaging measurements of glenoid version. Rotator cuff strength was also assessed at baseline using a handheld dynamometer. Internal and external rotation strength were assessed with the glenohumeral joint positioned in neutral and in 45° of abduction. The current study represents an analysis of the baseline data from this cohort. RESULTS: The mean age, height, and weight of participants was 18.77 ± 0.97 years, 176.81 ± 8.48 cm, and 73.80 ± 12.45 kg, respectively. The mean glenoid version at baseline was 7.79°± 4.85° of retroversion. Univariate linear regression analyses demonstrated that increased glenoid retroversion was associated with increased internal and external rotation strength of the rotator cuff in neutral and 45° of abduction (P < .001). Similar results were observed in multivariable models controlling for important confounding variables. CONCLUSION: The results of this study demonstrate that as glenoid retroversion increases, internal and external rotation strength of the rotator cuff also increase in a young and healthy athletic population. These compensatory changes may contribute to increased glenohumeral dynamic stability in the presence of worse static stability with increasing retroversion.

Level of Agreement Between Human-Rated and Instrumented Balance Error Scoring System Scores.

Clinicians have used the Balance Error Scoring System (BESS) to quantify postural control for concussion management. However, the reliability of the human rated BESS has varied prompting the development of instrumented BESSs. A cross-sectional design was used to determine the level of agreement (LOA) between human rated and instrumented BESS scores. Sixty participants completed the BESS on video. An instrumented mat was used to quantify BESS errors while a live human rater simultaneously scored the BESS. A second human rated BESS performance via video. Bland-Altman LOA analyses evaluated agreement between scoring methods (Mat-Human, Mat-Video, Video-Live) for each stance. Mean biases between scores, for each stance, with 95% confidence intervals (95%CIs) were calculated. Agreement between scoring methods was not assessed for the Firm-Double-Limb stance because very few errors were recorded. Agreement between both human raters and the mat was poor based on mean bias estimates > ± 1 and/or wide 95%CIs for all stances including BESS-Total. Agreement between the human raters was better, having displayed consistently smaller mean bias estimates and tighter 95%CIs for all stances and BESS Total. As a result, human rated and instrumented BESS scores may not be comparable. One method should be used to measure BESS errors for consistency.

A cohort study to identify and evaluate concussion risk factors across multiple injury settings: findings from the CARE Consortium.

BACKGROUND: Concussion, or mild traumatic brain injury, is a major public health concern affecting 42 million individuals globally each year. However, little is known regarding concussion risk factors across all concussion settings as most concussion research has focused on only sport-related or military-related concussive injuries. METHODS: The current study is part of the Concussion, Assessment, Research, and Education (CARE) Consortium, a multi-site investigation on the natural history of concussion. Cadets at three participating service academies completed annual baseline assessments, which included demographics, medical history, and concussion history, along with the Sport Concussion Assessment Tool (SCAT) symptom checklist and Brief Symptom Inventory (BSI-18). Clinical and research staff recorded the date and injury setting at time of concussion. Generalized mixed models estimated concussion risk with service academy as a random effect. Since concussion was a rare event, the odds ratios were assumed to approximate relative risk. RESULTS: Beginning in 2014, 10,604 (n = 2421, 22.83% female) cadets enrolled over 3 years. A total of 738 (6.96%) cadets experienced a concussion, 301 (2.84%) concussed cadets were female. Female sex and previous concussion were the most consistent estimators of concussion risk across all concussion settings. Compared to males, females had 2.02 (95% CI: 1.70-2.40) times the risk of a concussion regardless of injury setting, and greater relative risk when the concussion occurred during sport (Odds Ratio (OR): 1.38 95% CI: 1.07-1.78). Previous concussion was associated with 1.98 (95% CI: 1.65-2.37) times increased risk for any incident concussion, and the magnitude was relatively stable across all concussion settings (OR: 1.73 to 2.01). Freshman status was also associated with increased overall concussion risk, but was driven by increased risk for academy training-related concussions (OR: 8.17 95% CI: 5.87-11.37). Medical history of headaches in the past 3 months, diagnosed ADD/ADHD, and BSI-18 Somatization symptoms increased overall concussion risk. CONCLUSIONS: Various demographic and medical history factors are associated with increased concussion risk. While certain factors (e.g. sex and previous concussion) are consistently associated with increased concussion risk, regardless of concussion injury setting, other factors significantly influence concussion risk within specific injury settings. Further research is required to determine whether these risk factors may aid in concussion risk reduction or prevention.

Reference values for the Balance Error Scoring System as measured by the Tekscan MobileMat™ in a physically active population.

OBJECTIVES: The Balance Error Scoring System (BESS) is commonly used to measure postural stability; however, it has demonstrated inconsistent reliability values when administered by humans. The Tekscan MobileMat™ was developed to automate the assessment of BESS errors and eliminate rater subjectivity. The objective of this study was to report reference values for the BESS, as measured by the MobileMat™, and examine the effect of sex, concussion history, and competitive sport level on BESS performance. METHODS: Four hundred and forty participants performed the BESS on the MobileMat™. Participants were asked to maintain each stance with their eyes closed for 20 s. The MobileMat™ was used to quantify the number of errors. RESULTS: Concussion history (p = 0.279-0.979) and competitive sport level (p = 0.422-0.979) did not affect BESS performance. Males performed significantly better than females for the single-limb foam stance (p = 0.032). No sex differences were detected for the other BESS stances or BESS total score (p = 0.067-0.744). CONCLUSIONS: Previously reported reference values in collegiate athletes and adolescents were slightly higher thus highlighting the value in establishing population norms and in developing new technologies to objectively quantify BESS performance. Furthermore, sex, concussion history, and competitive sport level do not appear to influence BESS performance as measured by the MobileMat™.

Determinants of intention to disclose concussion symptoms in a population of U.S. military cadets.

OBJECTIVES: Non-disclosure of concussion complicates concussion management, but almost nothing is known about non-disclosure in military settings. This study describes concussion disclosure-related knowledge, attitudes, perceived social norms, perceived control, and intention. Additionally, the study identifies determinants of high intention to disclose concussion symptoms. DESIGN: Cross sectional survey. METHODS: First-year service academy cadets completed a cross-sectional survey to assess perceptions of concussion disclosure. Independent variables included: gender, race, ethnicity, high school athlete status, NCAA athlete status, previous concussion history, previous concussion education, socioeconomic proxy, concussion-related knowledge, attitudes about concussion, perceived social norms (perceived peer/organizational support and actions), and perceived control over disclosure. Log-binomial regression was used to identify determinants of high intention to disclose concussion symptoms. RESULTS: A total of 972 first-year military service academy cadets completed the survey [85% response; age=18.4±0.9y]. In the simple models, previous concussion history was associated with lower intention to disclose concussion symptoms. High perceived control over disclosure, higher concussion knowledge, more favorable attitudes and social norms about concussion were associated with high intention to disclose. In the multivariable model, a 10% shift towards more favorable perceived social norms (PR=1.28; p<0.001) and attitudes (PR=1.07; p=0.05) about concussion were associated with high intention to disclose concussion symptoms. High perceived control over disclosure was associated with high intention to disclose concussion symptoms (PR=1.39; p=0.08). CONCLUSIONS: Concussion-related perceived social norms, attitudes, and perceived control are associated with intention to disclose. Organizationally appropriate intervention strategies can be developed from these data.

Sex and number of concussions influence the association between concussion and musculoskeletal injury history in collegiate athletes.

OBJECTIVES: Examine the association between concussion and lower extremity injury in collegiate athletes and the influence of sex and the number of concussions on this relationship. METHODS: A total of 468 collegiate student-athletes (200 Males, 268 Females) were recruited from collegiate athletic facilities of three universities to participate in this retrospective review. Participants provided injury history (concussions, ankle sprains, and knee injuries) information through a survey. Chi-square tests and odds ratios examined the relationship between concussion and ankle sprain or knee injury history within each sex and based on concussion history (0, 1, >1). RESULTS: Females athletes with a concussion history had greater odds of reporting an ankle sprain or knee injury compared to females with no concussion history (OR = 1.88-2.54; p ≤ 0.020). Male athletes with a concussion history did not have greater odds of reporting an ankle sprain or knee injury. Athletes reporting multiple concussions had the greatest odds of ankle sprain or knee injury history compared to athletes with no previous concussions (OR = 2.43-2.56; p ≤ 0.004). No differences were identified between athletes with a single or multiple concussion history. CONCLUSION: Female athletes with a concussion history or participants with a multiple concussion history had the greatest odds of reporting an ankle or knee injury history compared to athletes with no concussion history.

Change in KOOS and WOMAC Scores in a Young Athletic Population With and Without Anterior Cruciate Ligament Injury.

BACKGROUND: Several studies have examined changes in patient-reported outcome measures (PROMs) after anterior cruciate ligament (ACL) injury, but no studies to date have prospectively evaluated changes from preinjury baseline through injury and follow-up among ACL-injured patients compared to the baseline and follow-up changes of uninjured patients. PURPOSE: To examine changes in PROMs over time from preinjury baseline to at least 2 years after ACL reconstruction and to compare these changes with those of an uninjured control group having similar physical activity requirements. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: The authors conducted a prospective cohort study with a nested case-control analysis at a US service academy. All incoming first year students were recruited to participate in this study. Consenting participants completed a baseline questionnaire that included the KOOS (Knee injury and Osteoarthritis Outcome Score), WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), and MARS (Marx Activity Rating Scale). Participants who sustained a subsequent ACL injury completed assessments at the time of surgery and at 6, 12, and 24 months after surgery. Healthy participants were recruited to repeat the baseline assessments within 1 year of graduation. Inter- and intragroup differences at these time points were evaluated with dependent and independent t tests, respectively. We also compared these results with established minimum clinically important difference (MCID) values. RESULTS: Of 1268 first year students entering the academy, 1005 with no previous injuries consented to participate in this study (82% male, mean ± SD age 19 ± 1 years). Of those enrolled, 30 suffered an ACL injury and met the inclusion criteria for this study. Ninety uninjured control students who met the inclusion criteria completed follow-up assessments. There were statistically significant differences across all KOOS and WOMAC subscales between ACL-injured group and uninjured group at the time of the final follow-up assessment. Four KOOS subscales (Pain, Symptoms, Sports and Recreation Function, and Knee-Related Quality of Life) and the WOMAC Stiffness subscale demonstrated >8-point differences between groups, which exceeded the established MCID for these instruments. There were no significant differences between the ACL-injured group and uninjured groups noted for the MARS ( P = .635). At the time of final follow-up, the ACL-injured group also reported significant deficits on the WOMAC Stiffness subscale ( P = .032), the MARS ( P = .030), and all KOOS subscales, with the exception of Functional Activities of Daily Living, as compared with their preinjury baseline scores. These deficits exceeded the established MCID values for 3 KOOS subscales and the MARS. CONCLUSION: Patients with ACL injuries reported significant deficits on PROMs at least 2 years after surgical reconstruction in relation to preinjury baseline scores and an uninjured control group. Many of these deficits exceeded established MCID values.