Distal Abdominal Oblique Avulsion Injuries in Two Collegiate Hockey Players: A Case Report.

ABSTRACT: While injuries to the abdominal oblique muscles near their origin at the lower ribs are commonly seen in sports that require explosive trunk rotational movements such as baseball and tennis, there are few reports in the literature of avulsion injuries to these muscles from their distal attachments at the iliac crest. We present the case of two collegiate male hockey players who suffered such injuries as a result of a direct impact mechanism while rotated at the waist. These injuries should be suspected when patients have significant pain in the lower abdominal region worsened by flexion and rotation of the trunk and can be accurately characterized by musculoskeletal ultrasound or MRI. With a conservative rehabilitation program focused on core, hip adductor, and hip flexor strengthening, our athletes were able to return to game participation within 6 wk of the initial injury.

Linking the preference in a bilateral asymmetric task with handedness, footedness, and eyedness: The case of ice-hockey.

Most people know whether they are left-handed or right-handed, and usually base this assessment on preferences during one-handed tasks. There are several manual tasks that require the contribution of both hands, in which, in most cases, each hand plays a different role. In this specific case, holding an ice-hockey stick is particularly interesting because the hand placement may have an incidence on the playing style. In this study (n = 854), the main objective was to determine to what extent the way of holding an ice-hockey stick is associated with other lateralized preferences. Amongst the 131 participants reporting a preference for the left hand in unilateral tasks, 70.2% reported a preference for shooting right (placing the right hand in the middle of the stick); and amongst the 583 participants reporting a preference for writing with the right hand, 66.2% reported a preference for shooting left. 140 (16.4%) participants were classified as ambidextrous and 61.4% of them reported a preference for shooting right. This preference on the ice-hockey stick is closely correlated (uncrossed preference) to the way one holds a rake, shovel, or broom, or a golf club, but inversely related to the way one holds an ax and a baseball bat. The link between the way of holding the ice-hockey stick and eyedness or footedness is weak. These results are contrasted with the results reported by Loffing et al. (2014) and reveal the need to clarify the exact nature and requirements of the targeted tasks when studying bilateral asymmetric preferences.

The Impact of an 8-Week Resisted Sprint Training Program on Ice Skating Performance in Male Youth Ice Hockey Players.

ABSTRACT: Dietze-Hermosa, MS, Montalvo, S, Gonzalez, MP, and Dorgo, S. The impact of an 8-week, resisted, sprint training program on ice skating performance in male youth ice hockey players. J Strength Cond Res 38(5): 957-965, 2024-The purposes of this randomized control study were to (a) compare the effects of an on-ice versus an overground resisted sprint training intervention and a control condition and (b) identify changes in ice skating kinematics and kinetics after training intervention participation. Twenty-four youth ice hockey players were randomly allocated into 3 groups: (a) on-ice resisted sprint training (on-ice RST); (b) overground resisted sprint training (overground RST); and (c) body weight resistance training (control). During the 8-week intervention, the 2 RST groups engaged in sled towing methods, whereas the control group engaged in a body weight resistance training program twice a week. A series of individual, repeated-measures analysis of variances with post hoc pairwise comparisons were conducted for variables of interest. An interaction effect was noted for ice skating s-cornering agility drill completion time ( p = 0.01; ηp2 = 0.36), ice skating 30-m top speed completion time ( p = 0.04; ηp2 = 0.27), step length ( p = 0.04; ηp2 = 0.26), and knee angle at touchdown ( p = 0.03; ηp2 = 0.30). The on-ice RST group displayed superior improvements across ice skating tests compared with the control group. Data show that on-ice RST has the greatest transfer effect to ice skating metrics; however, improvements in certain ice skating metrics can be observed with overground training also.

An in-depth analysis of wound incidence and injury status among professional athletes: A comprehensive review.

This review aims to synthesize current knowledge on the incidence, characteristics and management of wounds and injuries among professional ice hockey athletes, with the specific focus on the emerging population of Chinese female players. An extensive literature search was conducted across several databases to gather data on injury patterns and wounds, causes, severity and prevention strategies in ice hockey. Special attention was given to studies involving female athletes and unique challenges faced by players in developing regions like China. The review also examined the impact of training modalities, protective equipment and medical interventions on injury rates. The findings reveal a significant seasonal fluctuation in wound incidence, with marked reduction following the preseason period. This trend underscores the effectiveness of adjusted training programmes and essential role of medical teams in injury prevention and rehabilitation. Analysis did not show significant difference in wound rates between technical and physical training sessions, suggesting that injuries are pervasive risk across all training activities. Skating, collisions and inadequate warm-ups were identified as the leading causes of wounds, highlighting areas for targeted preventive measures. The distribution of wounds across various body regions pointed to knee, lower back and wrist as the most vulnerable sites, necessitating focused protection and training adjustments. Ice hockey, particularly among female athletes in China, presents complex injury landscape characterized by the wide range of wounds. The study emphasizes the necessity of comprehensive, multidisciplinary approach to injury prevention that includes training modifications, enhanced protective gear and strategic medical oversight. By addressing the specific causes and patterns of injuries identified, stakeholders can better protect athletes from the inherent risks of the sport, promote safer play and extend career longevity.

Genotypic and Allelic Distribution of the CD36 rs1761667 Polymorphism in High-Level Moroccan Athletes: A Pilot Study.

Previous studies have shown that variations in the CD36 gene may affect phenotypes associated with fat metabolism as the CD36 protein facilitates the transport of fatty acids to the mitochondria for oxidation. However, no previous study has tested whether variations in the CD36 gene are associated with sports performance. We investigated the genotypic and allelic distribution of the single-nucleotide polymorphism (SNP) rs1761667 in the CD36 gene in elite Moroccan athletes (cyclists and hockey players) in comparison with healthy non-athletes of the same ethnic origin. Forty-three Moroccan elite male athletes (nineteen cyclists and twenty-four field hockey players) belonging to the national teams of their respective sports (athlete group) were compared to twenty-eight healthy, active, male university students (control group). Genotyping of the CD36 rs1761667 (G>A) SNP was performed via polymerase chain reaction (PCR) and Sanger sequencing. A chi-square (χ2) test was used to assess the Hardy-Weinberg equilibrium (HWE) and to compare allele and genotype frequencies in the "athlete" and "control" groups. The genotypic distribution of the CD36 rs1761667 polymorphism was similar in elite athletes (AA: 23.81, AG: 59.52, and GG: 16.67%) and controls (AA: 19.23, AG: 69.23, and GG: 11.54%; χ2 = 0.67, p = 0.71). However, the genotypic distribution of the CD36 rs1761667 polymorphism was different between cyclists (AA: 0.00, AG: 72.22, and GG: 27.78%) and hockey players (AA: 41.67, AG: 50.00, and GG: 8.33%; χ2 = 10.69, p = 0.004). Specifically, the frequency of the AA genotype was significantly lower in cyclists than in hockey players (p = 0.02). In terms of allele frequency, a significant difference was found between cyclists versus field hockey players (χ2 = 7.72, p = 0.005). Additionally, there was a predominance of the recessive model in cyclists over field hockey players (OR: 0.00, 95% CI: 0.00-0.35, p = 0.002). Our study shows a significant difference between cyclists and field hockey players in terms of the genotypic and allelic frequency of the SNP rs1761667 of the CD36 gene. This divergence suggests a probable association between genetic variations in the CD36 gene and the type of sport in elite Moroccan athletes.

Contact allergy in Swedish professional ice hockey players.

BACKGROUND: Professional ice hockey players may contract irritant and allergic contact dermatitis. AIMS: To investigate the presence of contact allergy (CA) in professional ice hockey players in Sweden. METHODS: Ten teams from the two top leagues were assessed for potential occupational exposure to sensitizers. Exactly 107 players were patch tested with an extended baseline series and a working series, in total 74 test preparations. The CA rates were compared between the ice hockey players and controls from the general population and dermatitis patients. RESULTS: One out of 4 players had at least one contact allergy. The most common sensitizers were Amerchol L 101, nickel and oxidized limonene. CA was as common in the ice hockey players as in dermatitis patients and significantly more common than in the general population. Fragrances and combined sensitizers in cosmetic products (fragrances + preservatives + emulsifier) were significantly more common in ice hockey players compared with the general population. CONCLUSION: The possible relationship between CA to fragrances and cosmetic products on the one hand and the presence of dermatitis on the other should be explored further.

Physical fitness metrics and their relationship to locomotor activity profiles among female international field hockey players across an Olympic cycle.

OBJECTIVES: The study explored the correlations between physical fitness metrics and match locomotor activity profiles. Furthermore exploring the transformations of both fitness tests as well as match locomotor activities over an Olympic cycle. DESIGN: Observational descriptive study. METHODS: Fitness testing (n = 24) and match locomotor activity (n = 102) profiles were collected. A Pearson's product-moment correlation and 95 % confidence intervals were calculated to determine relationships between metrics for each year. A mixed-effects model was used for repeated measures to identify differences in the physical fitness tests and match locomotor activity profiles between years. RESULTS: The YoYo intermittent reocvery testest level 1 changed significantly (p < 0.0001) and accounted for 29 % of the variance in average speed (p < 0.001, rrm (59) = 0.54) Upper and lower body muscular strength, also improved, evidenced by the 3RM bench press (p < 0.0001), and a 28 % (2017-2019) increase in 3RM squat (p < 0.0001). Also pull-ups increased from 4.2 ± 2.8 pull-ups (2017) to 10.0 ± 3.1 pull-ups (2020) (p < 0.0001) and. countermovement jump height increased over the study duration (p < 0.0001). Match total distances remained unchanged, while average speed increased significantly (p < 0.0001). High-speed running distance (p < 0.0003) and sprint counts (p < 0.0001), showed significant improvements over the study period. CONCLUSIONS: The study underscores noteworthy improvements in physical attributes and performance metrics over an Olympic cycle. Contributing valuable insights for enhancing athletic performance in hockey players competing in the Olympics.

The effect of match congestion on hip adductor squeeze strength in youth rink hockey players

Introduction Groin injuries are common among rink hockey players. Monitoring the main risk factors can reduce the likelihood of suffering such injury. The objective of this study was to evaluate the effect of a competitive congestion period on the squeeze strength of the hip adductor muscles in a group of adolescent rink hockey players, and whether the strength reduction exceeded the injury risk threshold (>15%) for sustaining a groin injury. Materials and Methods Twenty U-16 athletes (9 females) participated in the study. Eighty-three adductor strength measurements were recorded after 10 games (2109 min of play). Function was assessed using the Sport subscale of the Hip and Groin Outcome Score (HAGOS) questionnaire. A simple linear regression model was used to analyze the accumulated time-strength relationship, and the pre-tournament and post-tournament HAGOS results were compared. Results The accumulation of games resulted in a significant strength reduction in male players' (R2= 0.27), but not in females. Eighty-five percent of the sample had their strength reduced to values at risk compared to baseline strength, but none of them stopped their activity due to discomfort in the groin region. HAGOS results were not affected by the competitive congestion (p = 0.07–0.48). Conclusion Match congestion can negatively impact adductor strength. However, there may not be a relationship between strength loss above 15% and the appearance of a groin injury. (AU)

Investigating the Relevance of Maximal Speed and Acceleration in Varsity-Level Female Ice Hockey Players.

PURPOSE: To characterize and compare female ice hockey players' peak skating speed and acceleration ability during linear sprints and gameplay. We also sought to quantify the time spent at various speeds and the frequency of accelerations at different thresholds during games. METHODS: Seventeen varsity-level female ice hockey players (20 [1.4] y, 68.9 [4.9] kg, 167.6 [4.7] cm) participated in an on-ice practice session (performing 3 × 40-m linear sprints) and 4 regular-season games while being monitored using a local positioning system. Speed and acceleration were recorded from the sprint and within-game monitoring. Time on ice spent in relative skating speed zones and the frequency of accelerations at different intensities were recorded. RESULTS: Players' greatest peak speeds (29.5 [1.3] vs 28.3 [1.1] km/h) and accelerations (4.39 [0.48] vs 3.34 [0.36] m/s2) reached during gameplay were higher than those reached in linear sprinting (both P < .01). Peak in-game values were moderately predicted by linear sprint values for speed (r = .69, P < .01) but not for acceleration (r < .01, P = .95). Players spent little time at near-peak linear sprint speeds (≥80% [22.7 km/h], ∼3% time on ice; ≥90% [25.5 km/h], <1% of time on ice) during gameplay. However, 26% to 35% of accelerations recorded during the 4 games were ≥90% of linear sprint acceleration. CONCLUSIONS: Although skating speed may be advantageous in specific game situations, our results suggest that players spend little time at near-maximal speeds while accelerating frequently during games. This warrants further investigation of direction changes, skating transitions, repeated sprints, and other determinant variables potentially related to on-ice success and the implementation of training strategies to improve repeated acceleration or qualities beyond maximal skating speed.

Analysis of Sleep, Nocturnal Physiology, and Physical Demands of NCAA Women's Ice Hockey Across a Championship Season.

ABSTRACT: Merrigan, JJ, Stone, JD, Kraemer, WJ, Friend, C, Lennon, K, Vatne, EA, and Hagen, JA. Analysis of sleep, nocturnal physiology, and physical demands of NCAA women's ice hockey across a championship season. J Strength Cond Res 38(4): 694-703, 2024-The aims of this study were to evaluate the (a) relationships between daily physical demands and nighttime sleep, heart rate (HR), and heart rate variability (HRV); (b) weekly changes in physical demands and sleep; and (c) differences among positions and between training and competition during a competitive season in National Collegiate Athletic Association (NCAA) women's ice hockey. Twenty-five NCAA Division I women's ice hockey athletes wore a sensor at night to monitor sleep quantity or quality (e.g., time asleep and sleep efficiency) and physiology (e.g., HR and HRV). During training and competitions (31 regular season and 7 postseason), athletes wore performance monitoring systems to assess workload demands (e.g., training impulse and TRIMP). As internal workload (TRIMP, Time >80% of HRmax, Average HR) during training or competition increased, nocturnal HRV decreased, HR increased, and Sleep Duration, Sleep Score, and Readiness Score decreased that night. Across the season, athletes experienced lower HRV, but exhibited longer sleep durations. Training Distance, Duration, Time >80% HRmax, Average HR, and TRIMP decreased, whereas competition Total Distance, Duration, and TRIMP increased across weeks throughout the season. There were differences across positions and season blocks when evaluating these data at the mesocycle level. Athletes slept longer before competition compared with training, but physiological data did not differ. Competitions had greater physiological demands than training. We speculate that the increased focus on sleep hygiene, as evidenced by the increase in sleep over the season, may have served as a recovery aid to combat physiological stress of accumulated demands of competitions that increased over time into postseason tournaments.

In search for climate neutrality in ice hockey: A case of carbon footprint reduction in a Finnish professional team.

Mitigation actions in all sectors of society, including sports, to limit global warming have become an increasingly hot topic in public discussions and sports management. However, so far, there has been a lack of understanding and practical examples of how these organizations, especially in team sports, can holistically assess and reduce their climate impacts to achieve carbon neutrality. This paper presents a carbon footprint assessment, implemented actions for GHG emission reduction, and offers the example of a professional Finnish ice hockey team that achieved carbon neutrality. The study is based on a life cycle assessment method. The Results show that the team's carbon footprint was reduced from 350 tCO2eq by more than 50% between seasons 2018-2019 and 2021-2022 in the assessed categories. The most GHG emission reductions were achieved in the team's and spectators' mobility and ice hall energy consumption. Furthermore, the team compensated for their remaining emissions to achieve carbon neutrality. Multiple possibilities for further GHG emission reductions were recognized. The majority of the GHG emissions were linked to the Scope 3 category, indicating that co-operation with partners and stakeholders was a key to success in attaining carbon neutrality. This paper also discusses the possible limitations and challenges that sport organizations face in assessing climate impacts and reducing GHG emissions, as well as the prospects of overcoming them. Since there are many opportunities for sports to contribute to climate change mitigation, relevant targets and actions to reduce GHG emissions should be integrated into all sport organizations' management.

Cross-Sectional Study of the Anthropometric Profile and Nutrient Status of Elite Female Ice Hockey Players: Differences by Play Position.

Both the characteristics of ice hockey and the environmental conditions in which it is played affect the maintenance of the player's nutritional status and, therefore, their state of health and performance. The primary aim of this work was to examine the anthropometric profile, estimated energy expenditure, and macronutrient and micronutrient dietary intake of elite female ice hockey players by play position. As a secondary aim, their dietary intakes were compared with the recommendations. Hypotheses suggest variations in body composition based on ice hockey players' positions, with the expectation that these athletes may not align with energy and nutrient recommendations. Fifteen elite female ice hockey players were anthropometrically measured, basal metabolic rate and total energy expenditure were estimated, a 3-day, 24 h recall questionnaire was registered, and the results were compared with the recommended dietary intake for the Spanish population. Each player's position on the field requires an individualized physical and nutritional approach. There are no significant imbalances (p > 0.05) between energy and nutrient intake in relation to the Recommended Daily Intake (RDI); however, increasing the consumption of vegetables and seafood while reducing meat and fat intake would assist these athletes in maintaining a healthier energy balance, optimizing body composition, and aligning with nutritional parameters that are better suited to enhance physical performance.

Maximum Strength and Power as Determinants of Match Skating Performance in Elite Youth Ice Hockey Players.

ABSTRACT: Keiner, M, Kierot, M, Stendahl, M, Brauner, T, and Suchomel, TJ. Maximum strength and power as determinants of match skating performance in elite youth ice hockey players. J Strength Cond Res 38(6): 1090-1094, 2024-Maximum strength has a strong influence on speed-strength performances such as sprints and jumps. Important for sports practice is whether these findings are also reflected in game performance. Therefore, the aim of this study was to explore the influence of maximum strength and power performance on linear on-ice skating performance in testing and during game play. A cross-sectional study was conducted, and 24 highly trained male youth ice hockey players participated. Jump performances (countermovement jump [CMJ], drop jumps), maximum strength (1 repetition maximum [1RM] squat and isometric trap bar pull [ITBP]), and on-ice linear sprints (15 m [LS15], 30 m [LS30], flying 15 m [FLY15]) were measured. Match performances (among others: peak skating speed) were collected of 4 regular league games using a local positioning system. Correlation coefficient and explained variance were calculated ( ρ ≤ 0.05). Correlations between maximum strength and jump with on-ice linear sprint performance showed 1-35% explained variance. Correlations between "off ice" test (CMJ, relative 1RM) and game data (peak skating speed) showed 22-30% explained variance, respectively, while ITBP and DJ missed significant level. Between linear sprint and game performance showed 15-59% explained variance. In this study, a clear influence of 1RM in squatting and CMJ performance on on-ice linear sprint as well as in-game peak skating speed was observed. These findings show that strength and jumping performance can be valuable tests within a comprehensive test battery and indicate the relevance of strength and jumping tasks within the regular exercise program to improve in-game skating performance.

Who Reaches the NHL? A 20-Year Retrospective Analysis of Junior and Adult Ice Hockey Success in Relation to Biological Maturation in Male Swedish Players.

OBJECTIVES: This study investigated the relationship between biological maturation and success in adolescence and adulthood in male Swedish ice hockey players. METHODS: Anthropometric records of players in certified ice hockey high schools between 1998 and 2017 were retrieved (n = 4787). The database was complemented with records of Swedish junior national teams (U16, U18, U20) and National Hockey League (NHL) appearances. Biological maturation was recorded as a percentage of adult height (%AH), and selection probabilities were estimated using a generalised linear mixed effects model. Biological age was determined by comparing players with age-matched growth reference values. Categories of %AH, standard deviation z-scores and biological age offset describing early, on-time and late maturation were created. RESULTS: A total of 217 players had played on the U16 national team (junior success), and 96 reached the NHL (adult success). The difference [95% confidence interval (CI)] in baseline %AH between players with junior versus adult success was - 0.75 (- 0.39, - 1.11). Looking at age-offset categories in junior success, 30% of players were early maturing and 19% of players were late maturing, showing a bias towards early maturation (p < 0.01). In contrast, more late-maturing players (40%) achieved adult success than early-maturing players (25%), and NHL players had significantly later maturation [%AH: - 0.48 (- 0.80, - 0.16)] than non-NHL players. CONCLUSION: This unique 20-year analysis shows that junior success in male ice hockey is positively related to early maturation, while adult success is inversely related to advanced maturation. Ice hockey organisations should implement maturation assessments to optimise the development of both late- and early-matured players.

Sweat Characteristics and Fluid Balance Responses During Two Heat Training Camps in Elite Female Field Hockey Players.

We examined the sweat characteristics and fluid balance of elite female field hockey players during two heat training camps. Fourteen elite female field hockey players from the Australian national squad participated in two heat training camps held ∼6 months apart, following winter- (Camp 1) and summer-based training (Camp 2). Daily waking body mass (BM) and urine specific gravity (USG) were collected, along with several markers of sweat and fluid balance across two matches per camp. There was a 19% mean reduction in estimated whole-body sweat sodium concentration from Camp 1 (45.8 ± 6.5 mmol/L) to Camp 2 (37.0 ± 5.0 mmol/L; p < .001). Waking urine specific gravity ≥ 1.020 was observed in 31% of samples, with no significant differences in mean urine specific gravity or BM between camps (p > .05), but with substantial interindividual variation. Intramatch sweat rates were high (1.2-1.8 L/hr), with greater BM losses in Camp 1 (p = .030), resulting in fewer players losing ≥2% BM in Camp 2 (0%-8%), as compared with Camp 1 (36%-43%; p = .017). Our field data suggest that elite female field hockey players experience substantial sweat losses during competition in the heat regardless of the season. In agreement with previous findings, we observed substantial interindividual variation in sweat and hydration indices, supporting the use of individualized athlete hydration strategies.

The impact of COVID-19 on national hockey league players' return to play.

OBJECTIVE: Evaluate the on-ice performance and return to play (RTP) rate following COVID-19 for National Hockey League (NHL) players during the 2020-21 season. METHODS: Players with COVID-19 during the abbreviated 2020-21 season were identified using publicly accessible online sources. Demographics and on-ice metrics were accessed using the NHL's online statistics website. The length of time, rate of RTP, and games missed due to COVID-19 were analyzed. Primary outcomes included average time on ice (TOI) per game (TOI/G), average TOI per shift (TOI/S), and points per game (PPG) compared at different timepoints including pre- and post-COVID-19. RESULTS: A total of 73 players (47 forwards, 18 defensemen, 8 goalies) had a documented COVID-19 diagnosis during the abbreviated 2020-21 season. Players missed an average of 5.6 games (14.7 days) due to COVID-19. The post-COVID-19 RTP rate was 97.3%, including playoffs. No differences were found in TOI/G between the pre- (15.7 ± 3.9 min) and post-COVID-19 (15.8 ± 3.4 min, p = 0.874) or in the first (15.8 ± 4.0 min) and second week (15.9 ± 3.8 min, p = 0.925) returned. TOI/shift did not change from pre- (45.6 ± 5.3 sec) to post-COVID-19 (46.7 ± 4.6 sec, p = 0.035) or in first (46.2 ± 5.4 sec) and second week post-COVID-19 (46.2 ± 4.8 sec, p = .854). No differences were identified for PPG between career, pre-COVID-19, and post-COVID-19 (0.44 vs 0.38 vs 0.41; p = 0.274). CONCLUSION: RTP post-COVID was markedly high for NHL players. While the effects of COVID-19 on specific physiological measures remains to be elucidated, this study found NHL players do not have reduced performance following COVID-19.

Injury patterns in Swedish elite female and male ice hockey - A cross-sectional comparison of past-season's injuries.

OBJECTIVES: To describe and compare seasonal prevalence, anatomical location, severity, and onset of injuries between female and male elite ice hockey players. DESIGN: Cross-sectional survey study. SETTING: Elite ice hockey. PARTICIPANTS: Swedish elite ice hockey players (170 females & 190 males). MAIN OUTCOME MEASURES: Past season injuries reported on a modified version of the Oslo Sports Trauma Research Center overuse injury questionnaire. Proportions of players who experienced any and substantial problems, as well as respective injury severity scores were presented and compared between sexes. RESULTS: Highest seasonal prevalence was reported for hip/groin [31.1% (n = 112)], lower back [24.2% (n = 87)], and shoulder injuries [23.6% (n = 85)]. Prevalence of injuries was approximately similar between sexes. Substantial injuries were most prevalent in the hip/groin (13.3% [n = 48]) and knee (18.6% [n = 67]) region. Females reported a higher proportion of substantial hip/groin injuries. Most reported injuries were acute except for hip/groin and lower back injuries (74.4% and 81.8% due to overuse). CONCLUSION: Seasonal prevalence of injuries in elite ice hockey players were comparable between sexes. Acute injuries were most common but hip/groin as well as lower back injuries were predominantly due to overuse. The highest reported prevalence was found for hip and groin-, lower back-, and shoulder injuries.

On-field instrumented mouthguard coupling.

Instrumented mouthguard (iMG) sensors have been developed to measure sports head acceleration events (HAE) in brain injury research. Laboratory validation studies show that effective coupling of iMGs with the human skull is crucial for accurate head kinematics measurements. However, iMG-skull coupling has not been investigated in on-field sports settings. The objective of this study was to assess on-field iMG coupling using infrared proximity sensing and to investigate coupling effects on kinematics signal characteristics. Forty-two university-level men's ice hockey (n = 21) and women's rugby (n = 21) athletes participated in the study, wearing iMGs during 6-7 month in-season periods. Proximity data classified video-verified HAE recordings into four main iMG coupling categories: coupled (on-teeth), decoupling (on-teeth to off-teeth), recoupling (off-teeth to on-teeth) and decoupled (off-teeth). Poorly-coupled HAEs showed significantly higher peak angular acceleration amplitudes and greater signal power in medium-high frequency bands compared with well-coupled HAEs, indicating potential iMG movements independent of the skull. Further, even video-verified true positives included poorly-coupled HAEs, and iMG coupling patterns varied between the men's hockey and women's rugby teams. Our findings show the potential of using proximity sensing in iMGs to identify poorly-coupled HAEs. Utilizing this data screening process in conjunction with video review may mitigate a key source of sensor noise and enhance the overall quality of on-field sports HAE datasets.

Shoulder Check: Investigating Shoulder Injury Rates, Types, Severity, Mechanisms, and Risk Factors in Canadian Youth Ice Hockey.

OBJECTIVE: To describe shoulder-related injury rates (IRs), types, severity, mechanisms, and risk factors in youth ice hockey players during games and practices. DESIGN: Secondary analysis of data from a 5-year prospective cohort study, Safe-to-Play (2013-2018). SETTING: Canadian youth ice hockey. PARTICIPANTS: Overall, 6584 player-seasons (representing 4417 individual players) participated. During this period, 118 shoulder-related games and 12 practice injuries were reported. ASSESSMENT OF RISK FACTORS: An exploratory multivariable mixed-effects Poisson regression model examined the risk factors of body checking policy, weight, biological sex, history of injury in the past 12 months, and level of play. MAIN OUTCOME MEASURES: Injury surveillance data were collected from 2013 to 2018. Injury rates with 95% confidence interval (CI) were estimated using Poisson regression. RESULTS: The shoulder IR was 0.35 injuries/1000 game-hours (95% CI, 0.24-0.49). Two-thirds of game injuries (n = 80, 70%) resulted in >8 days of time-loss, and more than one-third (n = 44, 39%) resulted in >28 days of time-loss. An 83% lower rate of shoulder injury was associated with policy prohibiting body checking compared with leagues allowing body checking (incidence rate ratio [IRR], 0.17; 95% CI, 0.09-0.33). A higher shoulder IR was observed for those who reported any injury in the last 12-months compared with those with no history (IRR, 2.00; 95% CI, 1.33-3.01). CONCLUSIONS: Most shoulder injuries resulted in more than 1 week of time-loss. Risk factors for shoulder injury included participation in a body-checking league and recent history of injury. Further study of prevention strategies specific to the shoulder may merit further consideration in ice hockey.