Isokinetic muscular performance of the quadriceps in elite ice hockey players

On four occasions during a period of 17 months, isokinetic maximum knee extensor output (peak torque and contractional work) and input (integrated electromyographic activity) during single and repetitive contractions were measured in 10 male elite ice hockey players. The tests were performed in the middle and at the end of the competitive season, and after two office training periods involving different types of training. No significant changes in peak torque at single maximum contractions occurred for the whole group of players during the investigation. Nor did the slope of decline in contractional work or the plateau level of the ratio of contractional work:integrated electromyographic activity during repetitive contractions change significantly. The most obvious finding was great interindividual differences in muscular performance. Intraindividually, changes in both peak torque as well as in slope of decline in contractional work and in plateau level of the ratio of contractional work:integrated electromyographic activity occurred during the different training periods. We conclude that local muscle adaptations, measured by isokinetic procedures, occur in the quadriceps as a result of ordinary training and games in elite ice hockey players. Because of the great interindividual differences in muscular performance and the different responses to similar training, we suggest individual programs for leg muscle training in ice hockey players.     

Vestibular performance in high-level soccer and ice hockey players: Sport-specific norm values and implications

ObjectivesQuantitative vestibular testing in athletes after sports-related concussion (SRC) has become more popular due to accompanying injuries of the peripheral-vestibular organs that require targeted treatment. Sports-specific normative values are currently not available. Taking into account potential adaptational mechanisms, we obtained sports-specific, age- and peak-head-velocity-corrected normative values of peripheral-vestibular function and postural-stability in football (soccer, FB) and ice-hockey (IH) players.DesignRetrospective single-center case-control study.MethodPre-seasonal angular vestibulo-ocular reflex (aVOR) gains and cumulative-saccadic-amplitudes were obtained using the video-head-impulse test and performance in the balance-error-scoring-system (BESS) was recorded and compared in high-level FB-players (n = 510, 197 females) and IH-players (n = 210, males only) (age-range = 13-39y) and in healthy normals (n = 49, 22 females). Statistical analysis was performed using a generalized linear model.ResultsaVOR-gain values were significantly higher for FB-players than for IH-players (1.07 ± 0.21 vs. 0.98 ± 0.13, p < 0.001) and controls (1.07 ± 0.21 vs. 0.97 ± 0.17, p < 0.001). Significant age-related changes in aVOR-gains were only observed for the anterior and posterior canals in the IH-players. Cumulative-saccadic-amplitudes were clearly below established cut-off values (0.73°/trial). BESS scores were significantly higher in IH-players than in FB-players (15.4 ± 5.1 vs. 11.2 ± 4.9, p < 0.001).ConclusionsThe significantly better performance of the FB players in the vertical aVOR-gains and the BESS compared to the IH-players could be related to sports-specific differences influencing visuo-vestibular and balance performance. Therefore, we recommend using the established normative aVOR-gain values for high-level FB-players, whereas in IH obtaining individual pre-seasonal (baseline) aVOR-gain values is proposed. Further studies should add sports-specific normative aVOR-gain values for IH and other sports.     

The avoidability of head and neck injuries in ice hockey: an historical review

The number of minor traumatic brain injury (mTBI), cerebral concussions, is increasing and cannot be eliminated by any kind of equipment. Prevention strategies, such as the introduction of "checking from behind" rules have become effective in decreasing the number of severe spinal injuries. A new "head checking" rule should reduce mTBI in the same way in the following years. Mouthguards should be mandatory as an effective device for the prevention of dental and orofacial injuries, as well as reducing the incidence and severity of mTBI. A new internet database system, the International Sports Injury System (ISIS) should improve epidemiological analysis of head, face, and spinal injuries worldwide. ISIS should provide an internationally compatible system for continuous monitoring of risk factors, protective effects of equipment, and protective effects of equipment and effects of changes in rules through the years.     

Evaluation of cricket helmet performance and comparison with baseball and ice hockey helmets

BACKGROUND: Protective helmets in sport are important for reducing the risk of head and facial injury. In cricket and other sports with projectiles, national test standards control the minimum helmet performance. However, there are few field data showing if helmets are effective in reducing head injury. OBJECTIVES: (a) To examine the performance of cricket helmets in laboratory tests; (b) to examine performance with regard to test standards, game hazards, and helmet construction; (c) to compare and contrast these findings with baseball and ice hockey helmets. METHODS: Impact tests were conducted on a selection of helmet models: five cricket, two baseball, and two ice hockey. Ball to helmet impacts at speeds of 19, 27, 36, and 45 m/s were produced using an air cannon and a Hybrid III dummy headform and neck unit. Free fall drop tests with a rigid headform on to a selection of anvils (flat rigid, flat deformable, and hemispherical rigid) were conducted. Resultant headform acceleration was measured and compared between tests. RESULTS: At the lower speed impacts, all helmets produced a good reduction in headform acceleration, and thus injury risk. At the higher speed impacts, the effectiveness was less. For example, the mean maximum headform accelerations for all cricket helmets at each speed were: 67, 160, 316, and 438 g for 19, 27, 36, and 45 m/s ball speeds respectively. Drop tests on to a hemispherical anvil produced the highest accelerations. The variation in performance increased as the magnitude of the impact energy increased, in both types of testing. CONCLUSIONS: The test method used for baseball helmets in which the projectile is fired at the helmet may be superior to helmet drop tests. Cricket helmet performance is satisfactory for low speed impacts, but not for impacts at higher, more realistic, speeds. Baseball and ice hockey helmets offer slightly better relative and absolute performance at the 27 m/s ball and puck impacts.     

Ocular blunt trauma: loss of sight from an ice hockey injury

A case of ocular blunt trauma is described in which a 17 year old male ice hockey player collided with an opponent during a game. The opponent's stick travelled under the patient's half face visor and struck his left eye causing hyphema, angle recession, lens subluxation, and choroidal rupture over the macula, permanently reducing his vision to counting fingers. Sequelae of ocular blunt trauma are discussed along with methods of injury prevention by addressing players' behaviour and safety equipment. This injury is unlikely to have occurred with properly used full face protection.     

Injuries in international ice hockey. A prospective, comparative study of injury incidence and injury types in international and Swedish elite ice hockey

In this prospective study, we have investigated incidence, nature, and mechanisms of injury in the Swedish national hockey team during 40 international games. There were 19 injuries associated with absence from practice or games, and 17 facial lacerations. The incidence of injuries associated with absence was 79.2 per 1,000 player-game hours, compared to the corresponding incidence of 78.4 found for Swedish national hockey. The incidence of facial wounds was 70.8 per 1,000 player-game hours, compared to the incidence of 21.8 for Swedish national hockey. The high incidence of facial injuries in international hockey is due to a high rate of stick contact injuries. Stricter enforcement of rules and more widespread use of visors would reduce the number of facial injuries.     

Less efficient oculomotor performance is associated with increased incidence of head impacts in high school ice hockey

Objectives

To evaluate associations between pre-season oculomotor performance on visual tracking tasks and in-season head impact incidence during high school boys ice hockey.

Isokinetic resistance training combined with eccentric overload improves athletic performance and induces muscle hypertrophy in young ice hockey players

ObjectivesTo determine the combined effects of slow isokinetic resistance training and eccentric overload and compare it to traditional resistance training on strength, power, body composition and muscle hypertrophy in young ice hockey players.DesignExperimental, randomized trial.MethodsTwenty-two resistance-trained ice hockey players (18 ± 1 year) were assigned to either isokinetic resistance training and eccentric overload (ISO/ECC; n = 11) or traditional resistance training (TRAD; n = 11). Participants underwent supervised progressive resistance training for 8 weeks (2–3 sessions/week) involving lower body multiple-joint exercises (heavy squats and explosive jump squats). The ISO/ECC group performed their training using a computerized robotic engine system (1080 Quantum synchro, Sweden), whereas the TRAD group performed the same resistance exercises with isotonic loading. Before and after the intervention, participants were evaluated in 1RM back squat, loaded jump squats, sprint- and jump performance, body composition and muscle thickness using ultrasound measurement.ResultsSimilar moderate increases in 1RM back squat and power output in the jump squats were found in both the ISO/ECC and TRAD groups (11–17%, P < 0.01), whereas only the ISO/ECC group showed improvements in drop jump performance (9.8%, P = 0.01). Moreover, similar trivial changes in body composition were observed in both groups, while only the ISO/ECC training group increased muscle thickness in the vastus intermedius (P = 0.01) and rectus femoris muscles (P = 0.03).ConclusionsBoth modalities effectively increased maximal strength and power output, whereas isokinetic resistance training, combined with eccentric overload, improved drop jump performance and induced greater muscle hypertrophy than traditional training in young ice hockey players.     

Neck injuries from skate blades in ice hockey: a report of three cases

This article describes three neck slash injuries in amateur ice hockey players, with a fatal outcome in two. One player died of asphyxation secondary to hemorrhage into the respiratory passage, but the other died of hemorrhage from the main blood vessels in the neck, severed by the skate blade. All three were not wearing any neck protecting device. Neck slash injury from skate blades, as a preventable sports-related injury, and the need for neck protective equipment in preventing such injuries are discussed.     

The impact of face shield use on concussions in ice hockey: a multivariate analysis

OBJECTIVE: To identify specific risk factors for concussion severity among ice hockey players wearing full face shields compared with half face shields (visors). METHODS: A prospective cohort study was conducted during one varsity hockey season (1997-1998) with 642 male ice hockey players (median age 22 years) from 22 teams participating in the Canadian Inter-University Athletics Union. Half of the teams wore full face shields, and half wore half shields (visors) for every practice and game throughout the season. Team therapists and doctors recorded on structured forms daily injury, participation, and information on face shield use for each athlete. The main outcome measure was any traumatic brain injury requiring assessment or treatment by a team therapist or doctor, categorised by time lost from subsequent participation and compared by type of face shield worn. RESULTS: Players who wore half face shields missed significantly more practices and games per concussion (2.4 times) than players who wore full face shields (4.07 sessions (95% confidence interval (CI) 3.48 to 4.74) v 1.71 sessions (95% CI 1.32 to 2.18) respectively). Significantly more playing time was lost by players wearing half shields during practices and games, and did not depend on whether the athletes were forwards or defence, rookies or veterans, or whether the concussions were new or recurrent. In addition, players who wore half face shields and no mouthguards at the time of concussion missed significantly more playing time (5.57 sessions per concussion; 95% CI 4.40 to 6.95) than players who wore half shields and mouthguards (2.76 sessions per concussion; 95% CI 2.14 to 3.55). Players who wore full face shields and mouthguards at the time of concussion lost no playing time compared with 1.80 sessions lost per concussion (95% CI 1.38 to 2.34) for players wearing full face shields and no mouthguards. CONCLUSIONS: The use of a full face shield compared with half face shield by intercollegiate ice hockey players significantly reduced the playing time lost because of concussion, suggesting that concussion severity may be reduced by the use of a full face shield.     

Promoting respect for the rules and injury prevention in ice hockey: evaluation of the Fair-Play program

OBJECTIVE: To reduce the number of transgressions to the rule, the occurrence of violent acts and to prevent injuries, Hockey Québec adopted the Fair-Play Program (FPP). The objective of the present study was to evaluate the effectiveness of the FPP. METHODS: 52 Bantam (14-15 years) teams participated in this cohort study. In total, 49 games (13 with the FPP, 36 without FPP) were systematically assessed for transgressions to the rule. Body checking was allowed in all games. Transgressions to the rule data were obtained using a real time observation system in a natural setting, while injury data were collected through a self-administered questionnaire. Data were analysed using generalised linear models with generalised estimating equations accounting for potential team effect. RESULTS: The number of penalties per game was significantly lower (p < 0.01) for games played with the FPP. Overall, no difference was noted in the number of transgressions observed during games played with or without the FPP. Players in leagues where the FPP was used held their opponents more frequently (p < 0.0001). On the other hand, players in leagues without the FPP shoved and hit more (p = 0.05). No difference was noted in the injury rate for games played with or without the FPP. CONCLUSIONS: This study showed that the FPP is one of the tools available to help those in the hockey world promote fair play values. Moreover, this project clearly showed the importance of program evaluation and the value of direct observation in a natural setting.     

Injuries to the upper extremity in ice hockey: analysis of a series of 760 injuries

BACKGROUND: Injuries to the upper extremity are common in ice hockey. PURPOSE: To investigate the mechanisms, types, and severity of upper extremity ice hockey injuries in patients in different age categories. STUDY DESIGN: Retrospective cohort study. METHODS: We analyzed 760 consecutive upper extremity injuries in Finnish ice hockey players reported to an insurance company during 1996. RESULTS: The overall injury rate of upper extremity injuries was 14.8 per 1000 player-years; 70% occurred during games. Of the 861 injury types, 32% were contusions, 28% sprains or strains, and 27% fractures. Checking or other collisions with players caused 76% of the injuries to the shoulder (170 of 223), 55% of the injuries to the elbow (35 of 64), and 45% of the injuries to the distal extremity (213 of 473). Of the 561 injuries with known severity, 38% were major. The injury risk increased significantly with age, from players younger than 12 years to players 25 to 29 years of age. The injury profile among 15- to 19-year-old players was similar to that of adult players. CONCLUSIONS: Injuries to the upper extremity are relatively serious because of the high number of shoulder injuries and fractures. The frequency of injuries increased with age. A considerable proportion of upper extremity injuries was caused by body checking.     

Short-term eccentric exercise in newly diagnosed type II diabetics: an exploratory study

Purpose

Eccentric exercise has been proposed as an alternate modality for chronic disease patients who cannot tolerate strenuous or vigorous intensity exercise. However, there is limited information regarding the biological benefits of this type of training compared to ‘traditional’ exercise. In this exploratory randomised clinical trial, we evaluated the feasibility and efficacy of eccentric exercise in the amelioration of markers of insulin resistance and inflammation.

Methods

Ten participants (age 50.0 ± 15 years, BMI 31.3 ± 7.1 kg/m²) with newly diagnosed T2DM and a sedentary lifestyle were randomly assigned to eccentric or concentric training performed during ten 30-min sessions of aerobic exercise over a 2-week period. Fasting blood samples were obtained pre- and 24 h post-intervention to determine insulin resistance (HOMA-IR, OGTT) and circulating cytokine (IL-6, TNF-α) concentrations.

Results

Despite the reduced heart rate (p = 0.008), the eccentric training group performed more work over the ten training sessions (p = 0.016) with no differences in the participant’s perceived exertion (p = 0.69). No significant between- or within-group changes were observed for OGTT, HOMA-IR or markers of inflammation (p > 0.05). However, there was a modest but consistent amelioration of OGTT, IL-6 and TNF-α that was been observed in the eccentric training group but not in the concentric training group.

Conclusion

Preliminary findings from this exploratory study would tend to suggest that short-term eccentric exercise is well tolerated in previously sedentary T2DM patients and that the trend towards reductions in circulating insulin resistance and inflammatory markers requires validation in an adequately powered clinical trial conducted over a longer duration.     

Test for the determination of endurance fitness and training style in young ice hockey players

A test similar to the Conconi test was developed by the authors, to be used specifically with ice hockey players. The aim was to measure the aerobic performance capacity of these athletes. The results give us on one hand informations on the actual performance potential of these sportsmen. On the other hand, they enable us to design an optimal training schedule. With such data in hand, it becomes possible to determine which intensity of endurance training is optimally adapted to an individual's progress of performance. It is thus easier to develop the sought after basic fitness in youth players. 120 ice hockey players of several leagues had to go through either a Conconi test, or our modified, more sports specific Probst test. 54 of these were junior players (age 15-16). Our purpose in this paper is to discuss the aim of such endurance tests for youth players.     

Mechanisms of injury for concussions in university football, ice hockey, and soccer: a pilot study.

OBJECTIVE: To examine the mechanisms of injury for concussions in university football, ice hockey, and soccer. DESIGN: Prospective analysis. SETTING: McGill University. PATIENTS: All athletes participating in varsity football, ice hockey, and soccer. MAIN OUTCOME MEASURES: Athletes participating in university varsity football, ice hockey, and soccer were followed prospectively to determine the mechanisms of injury for concussions, whether certain mechanisms of injury causing concussions were more common in any of the three sports, whether different areas of the body seem to be more vulnerable to a concussion after contact, and whether these areas might be predisposed to higher grades of concussion after contact. RESULTS: There were 69 concussions in 60 athletes over a 3-year period. Being hit in the head or helmet was the most common mechanism of injury for all 3 sports. The side/temporal area of the head or helmet was the most probable area to be struck, resulting in concussion for both football and soccer. When examining the body part or object delivering the concussive blow, contact with another player's helmet was the most probable mechanism in football. CONCLUSION: The mechanisms of injury for concussions in football are similar to previously published research on professional football players. The mechanisms of injury for concussions in soccer are similar to past research on Australian rules football and rugby.     

Field-based evaluation of hip adductor and abductor strength in professional male ice hockey players: Reference values and influencing factors

ObjectivesTo provide reference values and examine the influence of hip/groin pain on hip adductor and abductor strength in professional male ice hockey players, by using a straightforward 5-min procedure.DesignCross-sectional study.SettingOn-field assessment of hip/groin muscle strength with dynamometry, together with the concomitant level of hip/groin pain with a visual analogue scale.ParticipantsProfessional male ice hockey players competing in the Swiss National League (n = 187).Main outcome measuresHip abductor strength, hip adductor strength and hip adductor:abductor ratio.ResultsReference values by playing position (goalkeepers, defenders and forwards) are provided for asymptomatic athletes. Players with hip/groin pain during adduction displayed lower hip adductor strength (p = 0.001) and hip adductor:abductor ratio (p = 0.012) than their symptom-free peers.ConclusionsThe presence of hip/groin pain during adductor testing may contribute to selective hip adductor weakness, whose cause-effect relation with possible groin problems remains to be demonstrated.     

Effects of a diet regimen on pituitary and steroid hormones in male ice hockey players.

Serum concentrations of androgens, cortisol, androgen binding proteins, pituitary hormones, together with anthropometric variables and sports performance were studied in two different elite male ice hockey teams. One of the teams (DIF, n = 22) participated in a special dietary program including reduction in fat from approximately 40 per cent of total energy intake (E%) to less than 30 E% and an increase in carbohydrate intake from 45 E% to about 55 E%, while the other (SSK, n = 21) served as a control group and had no special dietary program. The study covered a 7-month period. Basal values of serum testosterone, sex hormone binding globulin (SHBG), non-SHBG-bound testosterone (NST), cortisol, dehydroepiandrosterone sulfate (DHAS) and LH did not differ between the two teams. Serum concentrations of testosterone, SHBG, NST and cortisol increased significantly during the study period in the DIF group and were, with the exception of SHBG, significantly higher than in the SSK group at the end of the study (33.0 vs 26.8 nmol/l, p less than 0.05; 22.5 vs 18.3 nmol/l, p less than 0.05; and 548 vs 464 nmol/l, p less than 0.01). The ratio between NST and cortisol which was used as an index of anabolic/catabolic steroid balance did not change in either group during the study. A significant decrease in the serum concentrations of LH during the observation period was found in the SSK group. The endocrine differences between the teams may be explained by a relative negative energy balance in DIF, together with a reduced fat and increased carbohydrate intake.(ABSTRACT TRUNCATED AT 250 WORDS)