Collegiate Ice Hockey Research Articles

Prevalence of shoulder labral abnormalities on MRI in a non-athletic asymptomatic young adult population.

To determine the prevalence of shoulder (specifically labral) abnormalities on MRI in a young non-athletic asymptomatic cohort. We hypothesize that this population will have fewer labral abnormalities than an athletic population. In this cross-sectional study, non-athletic young adults age 18-29 with no history of shoulder pain received bilateral shoulder MRIs. A total of 58 total shoulder MRIs were completed on a 3-T MRI scanner (PRISMA-Fit Siemens Medical). MRIs were read by two board-certified fellowship-trained musculoskeletal radiologists at two time points 3 months apart to determine prevalence of labral and other shoulder anatomy abnormalities. Kappa statistics and the associated 95% confidence intervals were computed for inter/intra-reader reliability. Fisher's exact test was used to compare rates of abnormalities in our study with a similarly designed study involving ice hockey athletes. Prevalence of labral abnormalities was 9% (5/58). Kappa coefficient was 1.0 for both readers for intra-reader reliability and 0.57 for inter-reader reliability of labral abnormalities. We further compared our results in asymptomatic athletes with previously published work using the same protocol at our institution. The prevalence of labral abnormalities on MRI in asymptomatic professional and collegiate ice hockey players (49 imaged shoulders) was 24%, which demonstrated a statistically significant (p value < 0.05) difference compared with our data with a p value of 0.03. Non-athletic young adults with no history of shoulder pain/injury had an overall prevalence of shoulder MRI abnormalities less than asymptomatic professional and collegiate ice hockey players in a similarly designed study.

Validation Of Player Tracking Sensors For Measuring Sprint Speed With Collegiate Ice Hockey Players

Validation Of Player Tracking Sensors For Measuring Sprint Speed With Collegiate Ice Hockey Players

Comparison Of Off-ice And On-ice Performance Tests In Collegiate Ice Hockey Players

Ice hockey is a high-intensity sport that requires optimally performing energy systems to compete at an elite level. Typically, off-ice performance tests are used to evaluate player fitness, but little is known about their relationships to on-ice tests. PURPOSE: To compare performance, blood lactate (LAC), and heart rate (HR) obtained during off- and on-ice fitness tests in collegiate ice hockey players. METHODS: Nineteen male, collegiate ice hockey players, (age=18-24 yr; ht=1.81±0.05m, wt=84.9±4.74 kg) were assessed off-ice using a discontinuous, incremental treadmill (TM) test. 3-min run stages were separated by 90-sec rest, until players reached volitional exhaustion. The on-ice test, in full gear, was a repeated shift ability (RSA) test consisting of eight, ~22-sec stages of maximal effort skating with 90-sec rest between stages. Fatigue decrement index (FDI) was calculated by subtracting fastest from slowest RSA stage times. During both tests, fingerstick LAC was obtained during rest intervals and HR was measured continuously. Spearman correlations were used to assess the relationship between TM completion time and FDI, as well as the relationships in Stage4 LAC and HRrecovery between off- and on-ice tests. RESULTS: TM times to exhaustion averaged 19.8±1.1 min, and RSA times averaged 22.0±0.4 sec. Corrrelations revealed no relationship between TM time and FDI (r=0.301, ns). Average HRmax during the TM tests was 192±6 b.min-1 versus highest achieved HR of 175±9 b.min-1 (91% of TM HRmax) during the RSA tests. For the TM tests, Stage4 LAC and HRrecovery averaged 10.2±2.8mmol and reduction to 76±8% HRmax, respectively. For the RSA tests, Stage4 LAC and HRrecovery averaged 13.3±1.9mmol and reduction to 74±4%HRmax. Stage4 TM and RSA LAC values were significantly related (r=0.52, p<0.05); however no significant relationship existed between Stage4 TM and RSA values for HRrecovery (r=0.34, ns). CONCLUSION: The lack of relationship between TM time and FDI was expected given the two tests’ emphases on different energy systems and the homogeneity of the athletes’ overall fitness. Moderate to high correlation found between LAC measures, regardless of test modality, supports previous research from our lab indicating the predictive value of LAC measures on ice hockey player performance.

Collegiate and Professional Ice Hockey Athletic Trainers’ Hydration Practices and Knowledge: Part 1

Despite cool environments, ice hockey athletes are predisposed to hypohydration due to extensive equipment, high intensity activity, and high sweat rates. The purpose of this study was to determine hydration practices and awareness of fluid recommendations among athletic trainers (ATs) working with NCAA Division I, NCAA Division III, and professional ice hockey teams. Most professional ATs (90.1%) utilized at least one hydration status measure, while 61.7% of collegiate ATs did not measure hydration. Compared to Division I, more Division III ATs did not have electrolyte supplements (p &lt; .001) and believed they did not have adequate access through budget/sponsorship (p &lt; .001). Both professional (72.0%) and collegiate (53%) ATs reported athletes had open access to electrolyte supplements or gave them to any athlete who asked. Athletic trainers provided patient education and had fluids accessible to athletes. Areas to improve clinical practice include monitoring electrolyte supplement access and collegiate ATs assessing hydration status.

Collegiate and Professional Ice Hockey Athletic Trainers’ Hydration Practices and Knowledge: Part 2

An athletic trainer’s (ATs) role requires current knowledge about factors that can influence hydration status. The purpose of this study was to determine awareness of alcohol and caffeine effects on hydration. Participants were 94 ATs with NCAA Division I or III men’s and/or women’s ice hockey teams and 82 head ATs with professional ice hockey teams. The majority of ATs were correct regarding alcohol’s effects on hydration, specifically knowing alcohol increases urine output (92.1%), delays fluid recovery (81.7%), and dehydrates a euhydrated individual (83.5%). In contrast, fewer ATs were correct that moderate, regular consumption of caffeine does not cause dehydration (20.7%), delay fluid recovery (15.2%), or impair fluid regulatory hormones (9.8%). While ATs were knowledgeable about alcohol effects, there remains misconceptions about caffeine on hydration.

Early Sport Specialization and Subjective Hip and Groin Dysfunction in Collegiate Ice Hockey Athletes.

Sport specialization is a popular trend among youth athletes that has been associated with an increased risk for developing lower extremity overuse injuries. Early ice hockey specialization may contribute to the high rates of noncontact and overuse hip and groin injuries in collegiate ice hockey athletes. To examine the effects of high, moderate, and low levels of sport specialization on subjective hip and groin dysfunction in collegiate ice hockey athletes. Retrospective cohort study. Data were collected during the midseason of the 2018-2019 hockey season at a local ice hockey arena. National Collegiate Athletic Association Division III and club ice hockey players from Midwestern college programs (n = 187; 81 women, 106 men). Participants were stratified into high-, moderate-, and low-specialization groups based on ice hockey participation before grade 9 of high school. The 6 subscales of the Hip and Groin Outcome Score questionnaire were used to assess current subjective hip and groin dysfunction. The high-specialization group had lower scores than the low-specialization group on the Symptoms (P = .001), Pain (P = .003), Activities of Daily Living (P = .001), Sport and Recreation (P = .014), and Quality of Life (P = .002) subscales. The moderate-specialization group had lower scores than the low-specialization group on the Symptoms (P = .015) and Activities of Daily Living (P = .006) subscales. Collegiate ice hockey athletes who were highly specialized before high school reported greater current hip and groin pain, symptoms, and dysfunction during activities of daily living and sport and recreation and lower current hip- and groin-related quality of life compared with low-specialization ice hockey athletes. Early ice hockey specialization may be detrimental to hip and groin function in collegiate ice hockey athletes.

Prevalence of MRI Shoulder Abnormalities in Asymptomatic Professional and Collegiate Ice Hockey Athletes.

Background:The literature demonstrates a high prevalence of asymptomatic knee and hip findings on magnetic resonance imaging (MRI) in athletes. Baseball pitchers are shown to have a high prevalence of asymptomatic shoulder MRI findings, but the incidence of asymptomatic shoulder MRI findings has not been systematically evaluated in nonthrowing contact athletes.Purpose/Hypothesis:The purpose of this study was to determine the prevalence of shoulder abnormalities in asymptomatic professional and collegiate hockey players. We hypothesized that, similar to overhead throwing athletes, ice hockey players will have a high prevalence of asymptomatic MRI findings, including labral, acromioclavicular (AC), and rotator cuff pathology on MRI.Study Design:Cross-sectional study; Level of evidence, 4.Methods:A total of 25 asymptomatic collegiate and professional hockey players (50 shoulders) with no history of missed games or practice because of shoulder injury, pain, or dysfunction underwent bilateral shoulder noncontrast 3.0-T MRI. MRIs were read blinded by 2 board-certified radiologists at 2 separate time points, 3 months apart, to determine the prevalence of abnormalities of the joint fluid, bone marrow, rotator cuff tendon, biceps tendon, labrum, AC joint, and glenohumeral joint. Interrater and intrareader reliability was determined, and regression analysis was performed to identify the prevalence and relationship to stick-hand dominance.Results:Labral abnormalities were seen in 25% of the shoulders. AC joint abnormalities and rotator cuff findings were noted in 8% and 6% of shoulders, respectively. One shoulder was noted to have a biceps tendon abnormality, and 1 shoulder demonstrated glenohumeral joint chondral findings. Interrater reliability coefficients were 0.619 for labral abnormalities. Intrareader reliability kappa coefficients were 0.493 and 0.718 for both readers, respectively, for labral abnormalities. Regression analysis was performed and revealed that the overall shoulder pathology was more common in the nondominant stick hand (top stick hand) (coefficient –0.731; P = .021).Conclusion:Professional and collegiate ice hockey players had an overall prevalence of labral abnormalities in 25% of their shoulders, with findings more often found in the nondominant stick hand. Rotator cuff abnormalities were uncommon in ice hockey players. These findings differ significantly from published reports examining professional baseball players and other overhead sports athletes.

Seasonal Changes in Physiological Responses and Body Composition During a Competitive Season in Male and Female Elite Collegiate Ice Hockey Players.

Delisle-Houde, P, Reid, RER, Insogna, JA, Chiarlitti, NA, and Andersen, RE. Seasonal changes in physiological responses and body composition during a competitive season in male and female elite collegiate ice hockey players. J Strength Cond Res 33(8): 2162-2169, 2019-Ice hockey continually overloads athletes with limited time for recovery, which may affect several physiological responses and alter body composition. The purpose of this study was to identify changes in physiological parameters and body composition profiles over the competitive season in elite collegiate ice hockey players. Forty-four players, 24 males (age = 22.7 ± 1.3 years, height = 1.82 ± 0.6 m, and body mass = 86.87 ± 6.44 kg) and 20 females (age = 19.9 ± 1.8 years, height = 1.66 ± 0.7 m, and body mass = 68.76 ± 5.91 kg) participated in 4-minute submaximal exercise tests and body composition assessments at pre-season, mid-season, and end-season. Changes in physiological parameters and body composition were analyzed using repeated-measures analysis of covariance controlling for age. Males' postexercise blood lactate concentration decreased (p ≤ 0.05) from pre- to mid-season (9.3 vs. 6.2 mmol·L) and increased (p ≤ 0.05) from mid- to end-season (6.2 vs. 8.0 mmol·L). Heart rate increased (p ≤ 0.05) after the third and fourth minute of the submaximal test in both sexes from pre- to end-season and from mid- to end-season. Males' body fat percentage decreased (p ≤ 0.05) from mid-season (17.4 vs. 16.1%), whereas increases were observed (p ≤ 0.05) in both sexes from mid- to end-season. This study produced evidence that male and female collegiate hockey athletes' physiological responses and body composition profiles change over the season. Sport scientists working with collegiate hockey teams, may need to revise annual training programs to attenuate reductions in fitness and hopefully prevent injuries.

Epidemiology of Foot and Ankle Injuries in National Collegiate Athletic Association Men's and Women's Ice Hockey.

Background:Ice hockey is a high-speed contact sport in which athletes are prone to many different injuries. While past studies have examined overall injury rates in ice hockey, foot and ankle injuries among collegiate ice hockey players have yet to be analyzed.Purpose/Hypothesis:The purpose of this study was to elucidate the epidemiology of foot and ankle injuries among collegiate ice hockey players utilizing data from the National Collegiate Athletic Association (NCAA) Injury Surveillance Program. We hypothesized that male ice hockey players would sustain more injuries compared with female ice hockey players and that the injuries sustained would be more severe.Study Design:Descriptive epidemiology study.Methods:Data on all foot and ankle injuries sustained during the academic years 2004 through 2014 were obtained from the NCAA Injury Surveillance Program. Injury rates, rate ratios (RRs), and injury proportion ratios were reported with 95% CIs.Results:Over the study period, the overall rate of foot and ankle injuries for men was higher than that for women (413 vs 103 injuries, respectively; RR, 4.01 [95% CI, 3.23-4.97]). Injury rates were highest during the regular season for both men (358 injuries; RR, 64.78 [95% CI, 58.07-71.49]) and women (89 injuries; RR, 38.37 [95% CI, 30.40-46.35]) compared with the preseason or postseason. The most common injury in men was a foot and/or toe contusion (22.5%), while women most commonly sustained a low ankle sprain (31.1%). For men, foot and/or toe contusions accounted for the most non–time loss (≤24 hours ) and moderate time-loss (2-13 days) injuries, while high ankle sprains accounted for the most severe time-loss (≥14 days) injuries. For women, foot and/or toe contusions accounted for the most non–time loss injuries, low ankle sprains accounted for the most moderate time-loss injuries, and high ankle sprains accounted for the most severe time-loss injuries.Conclusion:Foot and ankle injuries were frequent among collegiate ice hockey players during the period studied. For men, contusions were the most commonly diagnosed injury, although high ankle sprains resulted in the most significant time lost. For women, low ankle sprains were the most common and resulted in the most moderate time lost. These findings may direct future injury prevention and guide improvements in ice skate design.

Relationships between Head Impacts, Competitive Aggression, and Risk-taking Behavior in Collegiate Ice Hockey Players

Abstract Purpose To examine relationships between head impact kinematics sustained over a season and competitive aggression and self-reported risk-taking behavior in collegiate club ice-hockey athletes. Methods Twenty male ice-hockey players (19.9±1.2 y.o, 1.8±0.06 m, 78.5±5.7 kg) completed the Competitive Anger and Aggression Scale (CAAS, Range:0-84) and the Brief Sensation Seeking Scale (BSSS, Range:8-40) during the preseason as measures of competitive aggression and risk-taking behavior with higher/lower reflecting higher/lower aggression and risk taking. Penalty minutes (PM) and games played (GP) were taken from official game records. Head impact kinematics (number of impacts, linear mean, peak, cumulative acceleration) were recorded by tri-axial accelerometers worn during games/practices. Spearman correlation was performed to examine relationships between variables. Results The mean number of impacts was 76.6±54.9 (range: 6–171); mean and cumulative acceleration were 36.3±4.2g (range:27.8–42.2g) and 2829.4±2024.9g (range:198.4–6527.2g), respectively. Neither CAAS (mean: 48.7±10.9, range: 24–64) nor BSSS scores (mean: 25.3±4.4, range:15–32) were significantly related to impact kinematics. GP was significantly correlated with number of impacts (r=.63, p=.003) and cumulative linear acceleration (r=.61, p=.004). PM was significantly correlated with number of impacts (r=.52, p=.20) and cumulative linear acceleration (r=.55, p=.13). Conclusion There were no relationships between the head impact kinematics and self-reported aggressiveness or risk taking behavior, but more PM was strongly related to higher head impact loads. Considering PM may be useful in aiding to identify athletes who may sustain higher head impact loads, however, self-reports of behavior may not be.

Effects Of 3D Multiple Object Tracking On Head Impacts During A Collegiate Ice Hockey Season

Player-to-player contact is the most frequent head impact mechanism in collegiate ice hockey. Training with three-dimensional multiple object tracking (3D-MOT) could potentially reduce the quantity and severity of head impacts by enhancing player anticipation of these impacts. PURPOSE: The purpose of this study was to utilize 3D-MOT training as a tool to reduce the quantity and severity of head impacts in NCAA Division III men’s and women’s ice hockey players. METHODS: Collegiate men’s and women’s ice hockey players (N = 33; men = 17, women = 16) were randomly assigned to a 3D-MOT group (3D-MOT = 17) or control group (C = 16). 3D-MOT training occurred twice per week for 12 weeks throughout one regular season. Quantity, location, linear acceleration, and rotational velocity of head impacts were measured in practices and games. Independent samples t-tests compared peak linear acceleration and peak rotational velocity between groups. Pearson chi square analysis compared the quantity of impacts between groups. Independent groups ANOVAs compared peak linear acceleration and peak rotational velocity of impacts between player positions and peak linear acceleration and peak rotational velocity at five different helmet locations between groups. RESULTS: 3D-MOT forwards sustained head impacts with greater mean peak linear acceleration (3D-MOT = 41.33 + 28.54g; C = 38.03 + 24.30g) and mean peak rotational velocity (3D-MOT = 13.59 + 8.18 rad.sec-1; C = 12.47 + 7.69 rad.sec-1) in games, and greater mean peak rotational velocity in practices versus control forwards (3D-MOT = 11.96 + 6.77 rad.sec-1; C = 10.22 + 6.95 rad.sec-1). Conversely, 3D-MOT defensemen sustained fewer in-game head impacts (3D-MOT = 181 head impacts; C = 282 head impacts) and head impacts with a mean peak rotational velocity less than control defensemen (3D-MOT = 11.54 + 6.76 rad.sec-1; C = 13.65 + 8.43 rad.sec-1). There was no significant difference for all other parameters analyzed between 3D-MOT and control groups. CONCLUSION: 3D-MOT training reduced the quantity and severity of head impacts for defensemen in games, but not for forwards. Player position may play an important role in future interventions to reduce quantity and severity of head impacts in collegiate ice hockey.

Three-dimensional Multiple Object Tracking’s Role In Injury Incidence Reduction In Collegiate Athletics

Three-dimensional multiple object tracking (3D-MOT) has been proposed as a training tool for processing dynamic events such as sports activities, and has been hypothesized to reduce athletic injuries through increased awareness of player movement. PURPOSE: The purpose of this study was to determine if 3D-MOT is an effective intervention to minimize the risk of injury in collegiate ice hockey and lacrosse. METHODS: 78 NCAA Division III ice hockey and lacrosse players volunteered for a season-long investigation. Players were assigned to a 3D-MOT training intervention (3D-MOT; n=38) or a control group (C; n = 40). 3D-MOT training gains were measured by mean speed threshold (m/s) obtained from Core training sessions and were analyzed using paired t-tests. Athletic trainers (ATs) attended school-sanctioned team conditioning sessions, practices, and competitions from which injury data was collected. Repeated measures analysis of variance (RM-ANOVA) were performed to compare total number of injuries over time and between groups (3D MOT and C). Two additional RM-ANOVA were performed to explore if 3D-MOT training decreased the number of injuries over time based on injury mechanism (i.e., contact vs. non-contact). RESULTS: The mean speed threshold significantly increased from the first Core session to the last Core session (p=0.000). The total number of injuries significantly decreased over the course of the season (p=0.002). When comparing the 3D-MOT to C, there was no significant difference in the total number of injuries (p=0.293). For those injured at baseline, the total number of injuries also significantly decreased over time (p=.002) though the 3D-MOT intervention had no effect on the number of injuries in athletes injured at baseline (p=.204). The 3D-MOT intervention did not have an effect on mechanism of injury, however both contact (p=.016) and non-contact injuries (p=.013) significantly decreased over time (length of season). CONCLUSIONS: Motion perception training with 3D-MOT did not decrease injury incidence in NCAA Division III men’s and women’s ice hockey and lacrosse athletes compared to controls. NCAA Division III men’s and women’s ice hockey and lacrosse athletes experience fewer injuries, both contact and non-contact, as their seasons’ progress.

Effect Of 3d Multiple Object Tracking Training On Collegiate Ice Hockey And Lacrosse Game Performance

Effect Of 3d Multiple Object Tracking Training On Collegiate Ice Hockey And Lacrosse Game Performance

Effects of Optimizing the Respiratory Pump on Performance During a Simulated Ice Hockey Period

Ice hockey requires high-intensity activity during shifts with inactive recovery between shifts. During recovery periods, blood may pool in the legs, reducing central blood volume and the ability to clear lactic acid. Impedance threshold devices (ITD) were developed to treat conditions of central hypovolemia, such as hemorrhage. By creating a negative intrathoracic pressure, venous return is enhanced, increasing stroke volume and cardiac output. PURPOSE: To determine the effects of breathing with an ITD during recovery periods between simulated ice hockey shifts. METHODS: Five male collegiate ice hockey players skated a course, the Peterson On-Ice Repeated Sprint Test, eight times (shifts) with 90 s recovery between each shift. Each athlete completed two test sessions separated by 48 hr, one while breathing freely during the recovery periods (control condition) and one while breathing with the ITD during the recovery periods. RESULTS: Performance, measured as time to skate the course, was similar between conditions (p > .05). Average time to complete each shift was 22.10 ± 0.74 s (SEM) and increased with successive shifts. After shift 4, lactate was 12.0 ± 0.8 mM (control) and 11.0 ± 2.0 mM (ITD). After skating eight shifts, lactate continued to increase during the control condition (14.0 ± 0.4 mM) and was 28% higher than the ITD condition (10.9 ± 1.5 mM). Ratings of perceived exertion increased from shift 1 to shift 8 with the average slope of increase greater for the control condition (0.87, 95% CI 0.80-0.94) than the ITD condition (0.65, 95% CI 0.60-0.70, Z = -7.54, p < .001). CONCLUSIONS: Breathing with the ITD during recovery periods did not affect skating performance measured as time to complete each shift, but lactate was lower after shift 8 and athletes rated their exertion lower during the ITD condition. Thus, use of an ITD has potential to enhance recovery during repeated bouts of high-intensity, intermittent exercise.

Test-retest reliability of TRIMP in collegiate ice hockey players.

The utility of the heart rate derived variable TRaining IMPulse (TRIMP) for assessing internal training load in ice hockey players is not clear. Having a reliable measure of internal training load during on-ice training sessions would help coaches program exercise training. This study determined the reliability of TRIMP during on-ice training sessions in ice hockey players. Twelve Division I collegiate male ice hockey players (aged 18–23 years) had their heart rate (HR) data recorded during two on-ice practice sessions separated by two weeks. TRIMP and other descriptive HR variables were compared between sessions. TRIMP demonstrated moderate reliability during on-ice sessions. Systematic error, quantified as standardized change in means was negligible (–0.19); random error quantified as the percent typical error (%TE) was moderate (12.2%); and, test-retest correlation was very strong (0.75). TRIMP is suitable for quantifying training load during intermittent work in hockey athletes. The results from our study can be used to determine the threshold for meaningful change in TRIMP, which may aid in informing decisions by coaches and strength training staff regarding on-ice training session difficulty and composition.

Pediatric Sports Specialization in Elite Ice Hockey Players.

Background:Pediatric sports specialization, defined as intense year-round training in a single sport as a result of excluding other sports for more than 8 months per year, is common in the United States. There are demonstrated physical and social risks to early pediatric sports specialization (defined as before age 12 years). While thought to be needed to acquire appropriate experience and excel in a given sport, there remains little information on when athletes at the highest levels of their sport specialized. This study aimed to define when professional and collegiate ice hockey players specialized.Hypothesis:Early sports specialization before age 12 years will not be common among elite-level (professional and collegiate) ice hockey players.Study Design:Retrospective cross-sectional survey study.Level of Evidence:Level 3.Methods:Male professional and collegiate ice hockey players within 1 National Hockey League organization and 2 National Collegiate Athletic Association (NCAA) organizations who were 18 years of age or older completed a survey at training camp detailing their history of sports participation and specialization.Results:A total of 91 athletes participated in the study (mean age, 22.8 years; range, 18-39 years). The mean age at the start of any sports participation was 4.5 years, and the mean age of sports specialization was 14.3 years. The mean age of specialization in the professional group, the NCAA Division I group, and the NCAA Division III group was 14.1, 14.5, and 14.6 years, respectively.Conclusion:Early pediatric sports specialization is not common in elite-level (professional and collegiate) ice hockey players.Clinical Relevance:Early pediatric sports specialization before age 12 years is not necessary for athletic success in professional and collegiate ice hockey. This study provides further evidence supporting the recommendations of the American Medical Society for Sports Medicine, American Academy of Pediatrics, and American Orthopaedic Society for Sports Medicine against early sports specialization.

Training history constrains postural sway dynamics: A study of balance in collegiate ice hockey players

BackgroundBalance and postural control are integral to training and sport performance. Demands on posture are contextual and vary in different ways depending on the specific physical activity. Research questionThe purpose of this study was to examine the possibility that sustained exposure to environmental constraints, through specific sport participation, might lead to a persistent modification of postural control. MethodsDouble and single-leg postural sway were compared between ice hockey players, American football players and physically active college students. Data from 30 s trials were analyzed using traditional postural sway measures of range and pathlength of the center of pressure, as well as with Sample Entropy (SEn), in both mediolateral (ML) and anteroposterior (AP) directions. ResultsEach group displayed unique postural sway characteristics. During single-leg stance, ice hockey players show significantly different ML pathlength and ML and AP SEn from the physically active college students (all p < 0.05), and significantly different ML and AP pathlength and AP SEn from the American football players (all p < 0.05). The American football players and the physically active college students differed for all single-legged conditions (all p < 0.05). SignificanceThis suggests that the organization and development of postural sway is not only context dependent but also influenced by training history; supporting the idea that balance training for sport should be designed with regards to sport specific conditions.

Neuro-Metabolite Changes in a Single Season of University Ice Hockey Using Magnetic Resonance Spectroscopy

Background: Previous research has shown evidence for transient neuronal loss after repetitive head impacts (RHI) as demonstrated by a decrease in N-acetylaspartate (NAA). However, few studies have investigated other neuro-metabolites that may be altered in the presence of RHI; furthermore, the relationship of neuro-metabolite changes to neurocognitive outcome and potential sex differences remain largely unknown.Objective: The aim of this study was to identify alterations in brain metabolites and their potential association with neurocognitive performance over time as well as to characterize sex-specific differences in response to RHI.Methods: 33 collegiate ice hockey players (17 males and 16 females) underwent 3T magnetic resonance spectroscopy (MRS) and neurocognitive evaluation before and after the Canadian Interuniversity Sports (CIS) ice hockey season 2011–2012. The MRS voxel was placed in the corpus callosum. Pre- and postseason neurocognitive performances were assessed using the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). Absolute neuro-metabolite concentrations were then compared between pre- and postseason MRS were (level of statistical significance after correction for multiple comparisons: p < 0.007) and correlated to ImPACT scores for both sexes.Results: A significant decrease in NAA was observed from preseason to postseason (p = 0.001). Furthermore, a trend toward a decrease in total choline (Cho) was observed (p = 0.044). Although no overall effect was observed for glutamate (Glu) over the season, a difference was observed with females showing a decrease in Glu and males showing an increase in Glu, though this was not statistically significant (p = 0.039). In both males and females, a negative correlation was observed between changes in Glu and changes in verbal memory (p = 0.008).Conclusion: The results of this study demonstrate changes in absolute concentrations of neuro-metabolites following exposure to RHI. Results suggest that changes in Glu are correlated with changes in verbal memory. Future studies need to investigate further the association between brain metabolites and clinical outcome as well as sex-specific differences in the brain's response to RHI.

Epidemiology of Upper Extremity Injuries in NCAA Men’s and Women’s Ice Hockey

Background: Ice hockey is a physically demanding sport where athletes are susceptible to a variety of injuries. Several studies reported the overall injury rates in ice hockey; however, there is a paucity of information on upper extremity (UE) injuries among collegiate ice hockey players. Purpose: To describe the epidemiology of UE injuries among collegiate male and female ice hockey players with NCAA (National Collegiate Athletic Association) injury surveillance data from 2004-2005 to 2013-2014. Study Design: Descriptive epidemiology study. Methods: Data were obtained from the NCAA Injury Surveillance Program for all UE injuries sustained during the academic years 2004-2005 to 2013-2014. Injury rates, rate ratios (RRs), and injury proportion ratios were reported with 95% CIs. Results: During the 10 years studied, the overall rate of UE injuries for men was higher than that for women (236 vs 125 injuries per 100,000 athlete-exposures [AEs]; RR, 1.89; 95% CI, 1.67-2.15). UE injuries sustained during either pre- or postseason were approximately 3 times higher for men than for women (preseason: 149 vs 53 per 100,000 AEs; RR, 2.83; 95% CI, 1.69-4.74; postseason: 143 vs 49 per 100,000 AEs; RR, 2.91; 95% CI, 1.33-6.38). The overall injury rate was highest during the regular season (men: 257 per 100,000 AEs; 95% CI, 242-272; women: 143 per 100,000 AEs; 95% CI, 126-160). Additionally, the injury rate for men and women was higher during competition than practice (men: 733 vs 83 per 100,000 AEs; 95% CI, 687-780 and 75-92; women: 303 vs 64 per 100,000 AEs; 95% CI, 259-348 and 52-76). The most common injury observed was acromioclavicular joint sprain (men, 29.1%; women, 13.8%). For both groups, acromioclavicular joint injuries accounted for most non–time loss, moderate time loss (2-13 days), and severe time loss (≥14 days) injuries. Conclusion: Men and women sustained a significant number of UE injuries playing collegiate ice hockey during the period studied, with acromioclavicular joint sprain being the most common UE injury and the one that most frequently led to significant time loss. These data may provide insight for future injury prevention and guide improvements in training.

Characteristics of Female Collegiate Ice Hockey Players

Characteristics of Female Collegiate Ice Hockey Players