Physical activity and concussion risk in youth ice hockey players: pooled prospective injury surveillance cohorts from Canada.

OBJECTIVE: To examine the association between meeting physical activity (PA) volume recommendations and concussion rates in male ice hockey players aged 11-17 years. DESIGN: Pooled prospective injury surveillance cohort data from the 2011-2012, 2013-2014 and 2014-2015 youth ice hockey seasons. PARTICIPANTS: Male Alberta-based Pee Wee (aged 11-12 years), Bantam (aged 13-14 years) and Midget (aged 15-17 years) ice hockey players participating in any of the three cohorts were eligible (n=1726). A total of 1208 players were included after the exclusion criteria were applied (ie, players with new/unhealed injuries within 6 weeks of study entry, missing 6-week PA history questionnaires, missing game and/or practice participation exposure hours, players who sustained concussions when no participation exposure hours were collected). OUTCOME MEASURES: Dependent variable: medically diagnosed concussion. Independent variable: whether or not players' self-reported history of PA (ie, hours of physical education and extracurricular sport participation) met the Canadian Society of Exercise Physiology and Public Health Agency of Canada recommendation of one hour daily during the 6 weeks prior to study entry (ie, 42 hours or more). RESULTS: The PA volume recommendations were met by 65.05% of players who subsequently sustained concussions, and 75.34% of players who did not sustain concussions. The concussion incidence rate ratios (IRR) reflect higher concussion rates in players who did not meet the PA volume recommendations vs. players who met the PA volume recommendations among Pee Wee players (IRR 2.94 95% CI 1.30 to 6.64), Bantam players (IRR 2.18, 95% CI 1.21 to 3.93) and non-elite players aged 11-14 years (IRR 2.45, 95% CI 1.33 to 4.51). CONCLUSION AND RELEVANCE: The concussion rate of players who did not meet the Canadian PA volume recommendations was more than twice the concussion rate of players who met recommendations among male Pee Wee players, Bantam players and non-elite level players. Further exploration of the impact of public health PA recommendations in a sport injury prevention context is warranted.

The Effect of the "Zero Tolerance for Head Contact" Rule Change on the Risk of Concussions in Youth Ice Hockey Players.

BACKGROUND: Ice hockey is a popular winter sport in Canada. Concussions account for the greatest proportion of all injuries in youth ice hockey. In 2011, a policy change enforcing "zero tolerance for head contact" was implemented in all leagues in Canada. PURPOSE: To determine if the risk of game-related concussions and more severe concussions (ie, resulting in >10 days of time loss) and the mechanisms of a concussion differed for Pee Wee class (ages 11-12 years) and Bantam class (ages 13-14 years) players after the 2011 "zero tolerance for head contact" policy change compared with players in similar divisions before the policy change. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The retrospective cohort included Pee Wee (most elite 70%, 2007-2008; n = 891) and Bantam (most elite 30%, 2008-2009; n = 378) players before the rule change and Pee Wee (2011-2012; n = 588) and Bantam (2011-2012; n = 242) players in the same levels of play after the policy change. Suspected concussions were identified by a team designate and referred to a sport medicine physician for diagnosis. Incidence rate ratios (IRRs) were estimated based on multiple Poisson regression analysis, controlling for clustering by team and other important covariates and offset by game-exposure hours. Incidence rates based on the mechanisms of a concussion were estimated based on univariate Poisson regression analysis. RESULTS: The risk of game-related concussions increased after the head contact rule in Pee Wee (IRR, 1.85; 95% CI, 1.20-2.86) and Bantam (IRR, 2.48; 95% CI, 1.17-5.24) players. The risk of more severe concussions increased after the head contact rule in Pee Wee (IRR, 4.12; 95% CI, 2.00-8.50) and Bantam (IRR, 7.91; 95% CI, 3.13-19.94) players. The rates of concussions due to body checking and direct head contact increased after the rule change. CONCLUSION: The "zero tolerance for head contact" policy change did not reduce the risk of game-related concussions in Pee Wee or Bantam class ice hockey players. Increased concussion awareness and education after the policy change may have contributed to the increased risk of concussions found after the policy change.

The impact of concussion on cardiac autonomic function: A systematic review.

PRIMARY OBJECTIVE: To evaluate the evidence regarding the effect of concussion on cardiac autonomic function (CAF). INCLUSION CRITERIA: Original research; available in English; included participants with concussion or mild traumatic brain injury (mTBI) and a comparison group; included measures of heart rate (HR) and/or heart rate variability (HRV) as outcomes. Studies of humans (greater than 6 years old) and animals were included. Critical appraisal tools: The Downs and Black (DB) criteria and Structured Effectiveness Quality Evaluation Scale (SEQES). RESULTS: Nine full-length articles and four abstracts were identified. There is conflicting evidence regarding CAF at rest following concussion. There is evidence of elevated HR and reduced HRV with low-intensity, steady-state exercise up to 10 days following concussion. There was no significant difference in HRV during isometric handgrip testing or HR while performing cognitive tasks following concussion. The validity of current literature is limited by small sample sizes, lack of female or paediatric participants, methodological heterogeneity and lack of follow-up. CONCLUSIONS: While there is some evidence to suggest CAF is altered during physical activity following concussion, methodological limitations highlight the need for further research. Understanding the effect of concussion on CAF will contribute to the development of more comprehensive concussion management strategies.

Reliability and validity of two versions of the upper extremity functional index.

PURPOSE: To examine the reliability, validity, and sensitivity to change of the 20-item version and the Rasch-refined 15-item version of the Upper Extremity Functional Index (UEFI-20 and UEFI-15, respectively) and to determine the impact of arm dominance on the positive minimal clinically important difference (pMCID). METHODS: Adults with upper-extremity (UE) dysfunction completed the UEFI-20, Upper Extremity Functional Scale (UEFS), Pain Limitation Scale, and Pain Intensity Scale at their initial physiotherapy assessment (Time 1); 24-48 hours later (Time 2); and 3 weeks into treatment or at discharge, whichever came first (Time 3). Demographics, including working status, were obtained at Time 1. Global ratings of change (GRC) were provided by the treating physiotherapist and patient at Time 3. The UEFI-15 was calculated from relevant items in the UEFI-20. The intra-class correlation coefficient (ICC) and minimal detectable change (MDC) quantified test-retest reliability (Time 1-Time 2). Cross-sectional convergent validity was determined by the association (Pearson's r) between Time 1 measures of function and pain. Known-groups validity was evaluated with a one-way ANOVA across three levels of working status. Longitudinal validity was determined by the association (Pearson's r) between function and pain change scores (Time 1-Time 3). Receiver operating characteristic (ROC) curves estimated the pMCID using Time 1-Time 3 change scores and average patient/therapist GRC. RESULTS: Reliability for the UEFI-20 and UEFI-15 was the same (ICC=0.94 for both measures). MDC values were 9.4/80 for the UEFI-20 and 8.8/100 for the UEFI-15. Cross-sectional, known-groups, and longitudinal validity were confirmed for both UEFI measures. pMCID values were 8/80 for the UEFI-20 and 6.7/100 for the UEFI-15; pMCID was higher for people whose non-dominant arm was affected. CONCLUSIONS: Both UEFI measures show acceptable reliability and validity. Arm dominance affects pMCID. The UEFI-15 is recommended because it measures only one dimension: UE function.

Objectif : Étudier la fiabilité, la validité et la sensibilité au changement des versions à 20 questions et à 15 questions raffinées par Rasch de l'Indice fonctionnel des membres supérieurs (IFMS-20 et IFMS-15, respectivement) et déterminer l'effet du bras dominant sur la différence minimale positive cliniquement importante (pDMCI). Méthodes : Les adultes ayant une dysfonction des membres supérieurs (MS) ont répondu au questionnaire IFMS-20, aux questionnaires de l'Échelle fonctionnelle des membres supérieurs (EFMS), de l'Échelle de limitation de la douleur et de l'Échelle de l'intensité de la douleur au cours de leurs premières évaluations en physiothérapie (moment 1); de 24 à 48 heures plus tard (moment 2) et 3 semaines après le début du traitement ou le congé, selon l'échéance la plus rapprochée (moment 3). On a réuni des données démographiques, y compris sur leur état de travailleur, au cours du moment 1. Le physiothérapeute traitant et le patient ont fourni des évolutions globales du changement (EGC) au moment 3. On a calculé le résultat du questionnaire IFMS-15 à partir de questions pertinentes contenues dans la version IFMS-20. Le coefficient de corrélation intracatégorie (CCI) et le changement détectable minimal (CDM) ont quantifié la fiabilité de test­retest (moment 1­moment 2). La validité convergente transversale a été déterminée par le lien (r de Pearson) entre les mesures de fonction et de douleur prises au moment 1. On a évalué la validité des groupes connus au moyen d'une analyse bidirectionnelle des écarts (ANOVA) entre trois niveaux d'état de fonctionnement. La validité longitudinale a été déterminée en fonction du lien (r de Pearson) entre les scores de changement de la fonction et de la douleur (moment 1­moment 3). Des courbes des caractéristiques opérationnelles du récepteur (COR) ont estimé la pDMCI à partir des scores de changement entre le moment 1 et le moment 3 et les EGC moyennes patient/thérapeute. Résultats : La fiabilité des questionnaires IFMS-20 et IFMS-15 a été la même (CCI=0,94 pour les deux mesures). Les valeurs du CDM se sont établies à 9,4/80 pour le questionnaire IFMS-20 et à 8,8/100 pour le questionnaire IFMS-15. La validité transversale, de groupes connus et longitudinale a été confirmée pour les deux mesures de l'IFMS. Les valeurs de la pDMCI s'établissaient à 8/80 pour le questionnaire IFMS-20 et à 6,7/100 pour le questionnaire IFMS-15; la pDMCI était plus élevée chez les personnes dont le bras non dominant était atteint. Conclusions : Les deux mesures de l'IFMS montrent une fiabilité et une validité acceptables. Le bras dominant a un effet sur la pDMCI. On recommande le questionnaire IFMS-15 parce qu'il mesure une dimension seulement: la fonction des membres supérieurs.