No abstract

Purpose This study aimed to examine relationships among baseline demographics, symptom severity, computerized neurocognitive outcomes, and balance performance in collegiate athletes. Methods Collegiate varsity athletes (N = 207, age = 19.3 ± 1.0 yr) participating in an ongoing clinical research program who completed concussion baseline assessments including a demographic questionnaire, a graded symptom checklist, a neurocognitive assessment, and the Sensory Organization Test (SOT) were included in this study. The SOT composite equilibrium score (COMP) and three sensory ratio scores—vestibular (VEST), visual (VIS), and somatosensory (SOM)—were used to describe athletes’ overall sensory organization and ability to use input from each sensory system to maintain balance. Separate stepwise multiple linear regression models were performed for each SOT outcome. Total symptom severity level and CNS Vital Signs domain scores served as predictor variables. Results Stepwise regression models for COMP (R 2 = 0.18, F 4,201 = 11.29, P < 0.001), VEST (R 2 = 0.14, F 4,201 = 8.16, P < 0.001), and VIS (R 2 = 0.10, F 4,201 = 5.52, P < 0.001) were all significant. Faster reaction times and higher executive function scores were associated with higher COMP and VEST scores in separate models. Those with faster reaction times also had significantly higher VIS scores. Conclusion Reaction time and executive function demonstrated significant relationships with SOT balance performance. These cognitive processes may influence athletes’ ability to organize and process higher-order information and generate appropriate responses to changes in their environment, with respect to balance and injury risk. Future investigations should consider these relationships after injury, and clinicians should be mindful of this relationship when considering concussion management strategies.

Context: Prophylactic and rehabilitative balance training is needed to maximize postural control and develop appropriate sensory organization strategies. Partially occluding vision during functional exercise may promote appropriate sensory organization strategies, but little is known about the influence of partially occluded vision on postural control in those with and without a history of musculoskeletal injury. Objective: To determine the effect of increasing levels of visual occlusion on postural control in a heterogeneous sample of those with and without chronic ankle instability (CAI). The secondary objective was to explore postural control responses to increasing levels of visual occlusion among those with unilateral and bilateral CAI relative to uninjured controls. Design: Cross-sectional. Setting: Sports medicine research laboratory. Patients or Other Participants: Twenty-five participants with unilateral CAI, 10 with bilateral CAI, and 16 participants with no history of lower extremity injury. Main Outcome Measures: All participants completed four 3-minute postural control assessments in double-limb stance under the following 4 visual conditions: (1) eyes open, (2) low occlusion, (3) high occlusion, and (4) eyes closed. Low- and high-occlusion conditions were produced using stroboscopic eyewear. Postural control outcomes included time-to-boundary minima means in the anteroposterior (TTB-AP) and mediolateral directions (TTB-ML). Repeated-measures analysis of variances tested the effects of visual condition on TTB-AP and TTB-ML. Results: Postural control under the eyes-open condition was significantly better (ie, higher) than the limited visual occlusion and eyes-closed conditions (P < .001) for TTB-AP and TTB-ML. For TTB-AP only, partially occluded vision resulted in better postural control than the eyes-closed condition (P ≤ .003). Conclusions: Partial and complete visual occlusion impaired postural control during dual-limb stance in a heterogeneous sample of those with and without CAI. Stroboscopic eyewear appears to induce postural control impairments to the same extent as complete visual occlusion in the mediolateral direction.

Clinical Scenario: Current studies have identified body checking as the most common cause of sports-related concussion in ice hockey across all divisions and levels. As a result, many hockey organizations, particularly in youth sports, have implemented rules making body checking to the head, face, and/or neck illegal. Such a rule, in Canada, makes age 13 the first age in which individuals can engage in body checking. Despite these changes, effectiveness of their implementation on the incidence of concussion in Canadian male youth ice hockey players remains unclear. Clinical Question: What is the effect of body checking policy changes on concussion incidence in male youth ice hockey players? Summary of Key Findings: Of the 3 included studies, 2 studies reported a decrease in the incidence of concussion once a body checking policy change was implemented. The third study showed an increase; however, it is important to note that this may be due, in part, to increased awareness leading to better reporting of injuries. Clinical Bottom Line: Current evidence supports a relationship between body checking policy implementation and decreased concussion incidence; however, more research is needed to understand the long-term implications of policy change and the effects in other leagues. In addition, further data are needed to differentiate between increased concussion incidence resulting from concussion education efforts that may improve disclosure and increased concussion incidence as a direct result of policy changes. Strength of Recommendation: Grade B evidence exists that policy changes regarding body checking decrease concussion incidence in male youth ice hockey players.