Kevin M. Guskiewicz

Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012

This paper is a revision and update of the recommendations developed following the 1st (Vienna 2001), 2nd (Prague 2004) and 3rd (Zurich 2008) International Consensus Conferences on Concussion in Sport and is based on the deliberations at the 4th International Conference on Concussion in Sport held in Zurich, November 2012.1–3 The new 2012 Zurich Consensus statement is designed to build on the principles outlined in the previous documents and to develop further conceptual understanding of this problem using a formal consensus-based approach. A detailed description of the consensus process is outlined at the end of this document under the Background section. This document is developed primarily for use by physicians and healthcare professionals who are involved in the care of injured athletes, whether at the recreational, elite or professional level. While agreement exists pertaining to principal messages conveyed within this document, the authors acknowledge that the science of concussion is evolving, and therefore management and return to play (RTP) decisions remain in the realm of clinical judgement on an individualised basis. Readers are encouraged to copy and distribute freely the Zurich Consensus document, the Concussion Recognition Tool (CRT), the Sports Concussion Assessment Tool V.3 (SCAT3) and/or the Child SCAT3 card and none are subject to any restrictions, provided they are not altered in any way or converted to a digital format. The authors request that the document and/or the accompanying tools be distributed in their full and complete format. This consensus paper is broken into a number of sections 1. A summary of concussion and its management, with updates from the previous meetings; 2. Background information about the consensus meeting process; 3. A summary of the specific consensus questions discussed at this meeting; 4. The Consensus paper should be read in conjunction with the SCAT3 assessment tool, the Child SCAT3 and the CRT …

Unreported concussion in high school football players: implications for prevention

ObjectiveTo investigate the frequency of unreported concussion and estimate more accurately the overall rate of concussion in high school football players. DesignRetrospective, confidential survey completed by all subjects at the end of the football season. Setting and ParticipantsA total of 1,532 varsity football players from 20 high schools in the Milwaukee, Wisconsin, area were surveyed. Main Outcome MeasurementsThe structured survey assessed (1) number of concussions before the current season, (2) number of concussions sustained during the current season, (3) whether concussion during the current season was reported, (4) to whom concussion was reported, and (5) reasons for not reporting concussion. ResultsOf respondents, 29.9% reported a previous history of concussion, and 15.3% reported sustaining a concussion during the current football season; of those, 47.3% reported their injury. Concussions were reported most frequently to a certified athletic trainer (76.7% of reported injuries). The most common reasons for concussion not being reported included a player not thinking the injury was serious enough to warrant medical attention (66.4% of unreported injuries), motivation not to be withheld from competition (41.0%), and lack of awareness of probable concussion (36.1%). ConclusionsThese findings reflect a higher prevalence of concussion in high school football players than previously reported in the literature. The ultimate concern associated with unreported concussion is an athlete’s increased risk of cumulative or catastrophic effects from recurrent injury. Future prevention initiatives should focus on education to improve athlete awareness of the signs of concussion and potential risks of unreported injury.

Epidemiology of Concussion in Collegiate and High School Football Players

Despite evolutionary changes in protective equipment, head injury remains common in football. We investigated concussion in football and associated epidemiologic issues such as 1) incidence of injury, 2) common signs and symptoms, and 3) patterns in making return-to-play decisions. We received 242 of 392 surveys (62%) that were sent to high school and collegiate certified athletic trainers at the beginning of three football seasons. Of the 17,549 football players represented, 888 (5.1%) sustained at least one concussion, and 131 (14.7% of the 888) sustained a second injury during the same season. The greatest incidence of concussion was found at the high school (5.6%) and collegiate division III (5.5%) levels, suggesting that there is an association between level of play and the proportion of players injured. Players who sustained one concussion in a season were three times more likely to sustain a second concussion in the same season compared with uninjured players. Contact with artificial turf appears to be associated with a more serious concussion than contact with natural grass. Only 8.9% of all injuries involved loss of consciousness, while 86% involved a headache. Overall, 30.8% of all players sustaining a concussion returned to participation on the same day of injury.

Summary of evidence-based guideline update: Evaluation and management of concussion in sports Report of the Guideline Development Subcommittee of the American Academy of Neurology

Objective: To update the 1997 American Academy of Neurology (AAN) practice parameter regarding sports concussion, focusing on 4 questions: 1) What factors increase/decrease concussion risk? 2) What diagnostic tools identify those with concussion and those at increased risk for severe/prolonged early impairments, neurologic catastrophe, or chronic neurobehavioral impairment? 3) What clinical factors identify those at increased risk for severe/prolonged early postconcussion impairments, neurologic catastrophe, recurrent concussions, or chronic neurobehavioral impairment? 4) What interventions enhance recovery, reduce recurrent concussion risk, or diminish long-term sequelae? The complete guideline on which this summary is based is available as an online data supplement to this article. Methods: We systematically reviewed the literature from 1955 to June 2012 for pertinent evidence. We assessed evidence for quality and synthesized into conclusions using a modified Grading of Recommendations Assessment, Development and Evaluation process. We used a modified Delphi process to develop recommendations. Results: Specific risk factors can increase or decrease concussion risk. Diagnostic tools to help identify individuals with concussion include graded symptom checklists, the Standardized Assessment of Concussion, neuropsychological assessments, and the Balance Error Scoring System. Ongoing clinical symptoms, concussion history, and younger age identify those at risk for postconcussion impairments. Risk factors for recurrent concussion include history of multiple concussions, particularly within 10 days after initial concussion. Risk factors for chronic neurobehavioral impairment include concussion exposure and APOE ε4 genotype. Data are insufficient to show that any intervention enhances recovery or diminishes long-term sequelae postconcussion. Practice recommendations are presented for preparticipation counseling, management of suspected concussion, and management of diagnosed concussion.

Gender Differences in the Incidence and Prevalence of Patellofemoral Pain Syndrome

The purpose of this investigation was to determine the association between gender and the prevalence and incidence of patellofemoral pain syndrome (PFPS). One thousand five hundred and twenty‐five participants from the United States Naval Academy (USNA) were followed for up to 2.5 years for the development of PFPS. Physicians and certified athletic trainers documented the cases of PFPS. PFPS was defined as retropatellar pain during at least two of the following activities: ascending/descending stairs, hopping/jogging, prolonged sitting, kneeling, and squatting, negative findings on examination of knee ligament, menisci, bursa, and synovial plica, and pain on palpation of either the patellar facets or femoral condyles. Poisson and logistic regressions were performed to determine the association between gender and the incidence and prevalence of PFPS, respectively. The incidence rate for PFPS was 22/1000 person‐years. Females were 2.23 times (95% CI: 1.19, 4.20) more likely to develop PFPS compared with males. While not statistically significant, the prevalence of PFPS at study enrollment tended to be higher in females (15%) than in males (12%) (P=0.09). Females at the USNA are significantly more likely to develop PFPS than males. Additionally, at the time of admission to the academy, the prevalence of PFPS was not significantly different between genders.

A Prospective Investigation of Biomechanical Risk Factors for Patellofemoral Pain Syndrome The Joint Undertaking to Monitor and Prevent ACL Injury (JUMP-ACL) Cohort

Background Patellofemoral pain syndrome is one of the most common chronic knee injuries; however, little research has been done to determine the risk factors for this injury. Hypothesis Altered lower extremity kinematics and kinetics, decreased strength, and altered postural measurements will be risk factors. Study Design Cohort study (prognosis); Level of evidence, 2. Methods A total of 1597 participants were enrolled in this investigation and prospectively followed from the date of their enrollment (July 2005, July 2006, or July 2007) through January 2008, a maximum of 2.5 years of follow-up. Each participant underwent baseline data collection during their pre-freshman summer at the United States Naval Academy. Baseline data collection included 3-dimensional motion analysis during a jump-landing task, 6 lower extremity isometric strength tests, and postural alignment measurements (navicular drop and Q angle). Results Risk factors for the development of patellofemoral pain syndrome included decreased knee flexion angle, decreased vertical ground-reaction force, and increased hip internal rotation angle during the jump-landing task. Additionally, decreased quadriceps and hamstring strength, increased hip external rotator strength, and increased navicular drop were risk factors for the development of patellofemoral pain syndrome. Conclusion Multiple modifiable risk factors for patellofemoral pain syndrome pain have been identified in this investigation. To decrease the incidence of this chronic injury, the risk factors for patellofemoral pain syndrome need to be targeted in injury prevention programs. Clinical Relevance Prevention programs should focus on increasing strength of the lower extremity musculature along with instructing proper mechanics during dynamic movements to decrease the incidence of patellofemoral pain syndrome.

Postural stability assessment following concussion: one piece of the puzzle.

Clinicians regularly assess concussion according to the symptoms that an athlete manifests at the time of injury, as well as during subsequent evaluations. The subjectivity involved with symptom assessment, however, often leaves the clinician without a clear picture of the athletes true mental status. Neuropsychologic testing has become very popular in the sports medicine community for assessing the cognitive domain of neurologic functioning, and postural stability testing is gaining credence for assessing the motor domain. The objective of this review was to determine the efficacy of postural stability testing as an adjunct to concussion assessment of athletes. Multiple studies, using both sophisticated force plate technology, as well as those using less sophisticated clinical balance tests, have identified postural stability deficits lasting several days following sport-related concussion. It appears that postural stability testing provides a useful tool for objectively assessing the motor domain of neurologic functioning, and should be considered a reliable and valid adjunct to the assessment of athletes suffering from concussion. Although symptom severity, neurocognitive function, and postural stability are often affected initially following concussion, they are not necessarily related or even affected to the same degree.

Standard regression-based methods for measuring recovery after sport-related concussion

Clinical decision making about an athletes return to competition after concussion is hampered by a lack of systematic methods to measure recovery. We applied standard regression-based methods to statistically measure individual rates of impairment at several time points after concussion in college football players. Postconcussive symptoms, cognitive functioning, and balance were assessed in 94 players with concussion (based on American Academy of Neurology Criteria) and 56 noninjured controls during preseason baseline testing, and immediately, 3 hr, and 1, 2, 3, 5, and 7 days postinjury. Ninety-five percent of injured players exhibited acute concussion symptoms and impairment on cognitive or balance testing immediately after injury, which diminished to 4% who reported elevated symptoms on postinjury day 7. In addition, a small but clinically significant percentage of players who reported being symptom free by day 2 continued to be classified as impaired on the basis of objective balance and cognitive testing. These data suggest that neuropsychological testing may be of incremental utility to subjective symptom checklists in identifying the residual effects of sport-related concussion. The implementation of neuropsychological testing to detect subtle cognitive impairment is most useful once postconcussive symptoms have resolved. This management model is also supported by practical and other methodological considerations.

Consensus statement on concussion in sport-the 5th international conference on concussion in sport held in Berlin, October 2016

The 2017 Concussion in Sport Group (CISG) consensus statement is designed to build on the principles outlined in the previous statements1–4 and to develop further conceptual understanding of sport-related concussion (SRC) using an expert consensus-based approach. This document is developed for physicians and healthcare providers who are involved in athlete care, whether at a recreational, elite or professional level. While agreement exists on the principal messages conveyed by this document, the authors acknowledge that the science of SRC is evolving and therefore individual management and return-to-play decisions remain in the realm of clinical judgement. This consensus document reflects the current state of knowledge and will need to be modified as new knowledge develops. It provides an overview of issues that may be of importance to healthcare providers involved in the management of SRC. This paper should be read in conjunction with the systematic reviews and methodology paper that accompany it. First and foremost, this document is intended to guide clinical practice; however, the authors feel that it can also help form the agenda for future research relevant to SRC by identifying knowledge gaps. A series of specific clinical questions were developed as part of the consensus process for the Berlin 2016 meeting. Each consensus question was the subject of a specific formal systematic review, which is published concurrently with this summary statement. Readers are directed to these background papers in conjunction with this summary statement as they provide the context for the issues and include the scope of published research, search strategy and citations reviewed for each question. This 2017 consensus statement also summarises each topic and recommendations in the context of all five CISG meetings (that is, 2001, 2004, 2008, 2012 as well as 2016). Approximately 60 000 published articles were screened by the expert panels for the Berlin …

Examination of static and dynamic postural stability in individuals with functionally stable and unstable ankles.

Objective:To determine static and dynamic postural stability differences between functional ankle instability and stable ankle groups. Design:Subjects were required to balance on a single leg and remain motionless for 20 seconds. After completing 3 trials, they performed a jump-landing test, which required them to jump 50% to 55% of their maximum vertical jump height. They landed on a single leg, stabilized quickly, and remained motionless for 20 seconds. Setting:Sports Medicine Research Laboratory. Participants:Subjects with functional ankle instability (n = 14) who reported at least 2 sprains and “giving way” sensations at their ankle joint within the year prior to testing. Fourteen subjects with no history of ankle sprain injury were matched to subjects with functional ankle instability. Main Outcome Measures:Anterior/posterior and medial/lateral mean sway quantified static postural stability during single-leg stance. Dynamic postural stability was quantified with anterior/posterior and medial/lateral time to stabilization during single-leg jump landing. Results:Mean sway was not significantly different between groups in the anterior/posterior (P = 0.28) and medial/lateral (P = 0.65) directions. The functional ankle instability group took significantly longer to stabilize in the anterior/posterior (3.27 ± 0.72 seconds vs. 2.33 ± 0.33 seconds; P < 0.001) and medial/lateral (2.48 ± 0.50 seconds vs. 2.00 ± 0.65 seconds; P = 0.04) directions. Conclusions:Individuals with functional ankle instability took significantly longer to stabilize than individuals with stable ankles after a single-leg jump landing. Differences between groups were not detected with mean sway measured during single-leg stance.