The mechanical response to hockey-specific running gait: implications for the objective monitoring of (p)rehabilitation.

Field hockey is characterized by a unique dribbling position which has been associated with a prevalence of low back pain and lumbar injury. To quantify the biomechanical response of the hockey-specific running gait, twelve field hockey players completed treadmill running at speeds of 6, 9 and 12 km·hr-1 with a normal running gait and whilst manipulating the hockey stick to replicate dribbling. Mechanical loading was quantified using tri-axial accelerometery at L4, and muscular activity was measured for biceps femoris (BF), gluteus medius (GM) and quadratus lumborum (QL) of each limb. Running with the stick elicited greater mechanical loading in the medio-lateral (p = 0.001) and antero-posterior (p = 0.003) planes, and increased peak (p = 0.004) and mean (p = 0.002) EMG response of QL (p = 0.004). The greater planar mechanical loading and QL activation in response to hockey-specific running technique support epidemiological observations of lower back pain prevalence. The sensitivity of uni-axial mechanical loading to the hockey-specific running posture provides an efficacious means of objectively monitoring mechanical loading in-vivo, whilst the QL activation response has implications for (p)rehabilitative interventions. Running posture and speed can be considered as discrete progressions when considering training load.

Psychological characteristics of developing excellence in talented female field hockey players.

Psychological Characteristics of Developing Excellence (PCDEs) are a range of psychological factors that play a key role in the realisation of potential. We examined PCDE profiles across a female national talent development field hockey programme in North America. Two-hundred-and-sixty-seven players completed the Psychological Characteristics of Developing Excellence Questionnaire version 2 (PCDEQ-2) prior to the competitive season. One-hundred-and-fourteen players were classified as juniors (under-18) and 153 as seniors (over-18). Eighty-five players were classified as non-selected (not-selected to their age-group national team), and 182 as selected (selected to their age-group national team). A MANOVA showed multivariate differences based on age, selection status and their interaction, within this already homogenous sample, suggesting that sub-groups within this sample vary depending on their overall PCDE profiles. ANOVA showed differences in imagery and active preparation, perfectionist tendencies and clinical indicators between juniors and seniors. Furthermore, differences in imagery and active preparation, and perfectionist tendencies, were observed between selected and non-selected players. Subsequently, four individual cases were identified for further analysis based on their multivariate distance to the average PCDE profile. The use of the PCDEQ-2 at group- and particularly at individual-levels seems an important tool to support athletes as they navigate their development journey.

Contact injuries in field hockey and the potential role for personal protective equipment.

Field hockey is played with sticks and a hard ball. It is fast-paced, with athletes playing together in close proximity. Athletes may be at increased risk of sustaining injuries through contact. The aim of this study was to investigate the epidemiological characteristics of contact injuries in field hockey. Data were collected during the 2017/2018 and 2018/2019 Irish Hockey League seasons. This study included two methods of data collection among male athletes: self-reported injuries and via those reported by the teams' physiotherapists. Injuries were defined as any physical complaint sustained during field hockey, supplemented by medical attention and time-loss injuries. Only contact injuries were included for analysis. Overall, 107 contact injuries were incurred, giving rise to an injury incidence rate of 3.1/1000 h, and accounting for 33.1% of all injuries. Athletes had an absolute risk of 0.372 of sustaining a contact injury. Contusions (48.6%) were the most common type of contact injury, while injuries to the head/face (20.6%) were the most frequently reported location. Contact injuries represent an important proportion of all injuries. Rule changes to mandate the use of personal protective equipment in field hockey may assist in reducing the absolute risk and severity of contact injuries in field hockey.

Microdosing Sprint Distribution as an Alternative to Achieve Better Sprint Performance in Field Hockey Players.

Introduction: The implementation of optimal sprint training volume is a relevant component of team sport performance. This study aimed to compare the efficiency and effectiveness of two different configurations of within-season training load distribution on sprint performance over 6 weeks. Methods: Twenty male professional FH players participated in the study. Players were conveniently assigned to two groups: the experimental group (MG; n = 11; applying the microdosing training methodology) and the control group (TG; n = 9; traditional training, with players being selected by the national team). Sprint performance was evaluated through 20 m sprint time (T20) m and horizontal force−velocity profile (HFVP) tests before (Pre) and after (Post) intervention. Both measurements were separated by a period of 6 weeks. The specific sprint training program was performed for each group (for vs. two weekly sessions for MG and TG, respectively) attempting to influence the full spectrum of the F-V relationship. Results: Conditional demands analysis (matches and training sessions) showed no significant differences between the groups during the intervention period (p > 0.05). No significant between-group differences were found at Pre or Post for any sprint-related performance (p > 0.05). Nevertheless, intra-group analysis revealed significant differences in F0, Pmax, RFmean at 10 m and every achieved time for distances ranging from 5 to 25 m for MG (p < 0.05). Such changes in mechanical capabilities and sprint performance were characterized by an increase in stride length and a decrease in stride frequency during the maximal velocity phase (p < 0.05). Conclusion: Implementing strategies such as microdosed training load distribution appears to be an effective and efficient alternative for sprint training in team sports such as hockey.

Force-Velocity Profiling in Club-Based Field Hockey Players: Analyzing the Relationships between Mechanical Characteristics, Sex, and Positional Demands.

The purpose of this study was to investigate differences between sex and positional demands in club-based field hockey players by analyzing vertical force-velocity characteristics. Thirty-three club-based field hockey athletes (16 males - age: 24.8 ± 7.3yrs, body mass: 76.8 ± 8.2kg, height: 1.79 ± 0.05m; 17 females - age: 22.3 ± 4.2yrs, body mass: 65.2 ± 7.6kg, height: 1.66 ± 0.05m) were classified into two key positional groups (attacker or defender) based on dominant field position during gameplay. Force-velocity (F-v) profiles were established by performing countermovement jumps (CMJ) using a three-point loading protocol ranging from body mass (i.e., zero external mass, 0%) to loads corresponding to 25% and 50% of their own body mass. Across all loads, between-trial reliability of F-v and CMJ variables was determined by intraclass correlation coefficients (ICCs) and coefficient of variation (CV) and deemed to be acceptable (ICC: 0.87-0.95, CV% 2.8-8.2). Analysis by sex identified male athletes had significantly greater differences in all F-v variables (12.81-40.58%, p ≤ 0.001, ES = 1.10-3.19), a more enhanced F-v profile (i.e., greater theoretical maximal force, velocity, and power values), plus overall stronger correlations between relative maximal power (PMAX) and jump height (r = 0.67, p ≤ 0.06) when compared to female athletes (-0.71≤ r ≥ 0.60, p = 0.08). Male attackers demonstrated a more 'velocity-oriented' F-v profile compared to defenders due to significant mean differences in theoretical maximal velocity (v0) (6.64%, p ≤ 0.05, ES: 1.11), however differences in absolute and relative theoretical force (F0) (15.43%, p ≤ 0.01, ES = 1.39) led to female attackers displaying a more 'force-oriented' profile in comparison to defenders. The observed mechanical differences identify the underpinning characteristics of position specific expression of PMAX should be reflected in training programmes. Therefore, our findings suggest F-v profiling is acceptable to differentiate between sex and positional demands in club-based field hockey players. Furthermore, it is recommended field hockey players explore a range of loads and exercises across the F-v continuum through on-field and gym-based field hockey strength and conditioning practices to account for sex and positional mechanical differences.

The Physical and Physiological Match-Play Locomotor Activity Profiles of Elite Domestic Male Field Hockey.

A new four-quarter match format in field hockey has meant that the locomotor activity profiles of the sport are inconsistent with the literature. The aim of this investigation was to identify the physical and physiological demands of national-level male hockey players. Thirty-two male players participated in the study. Participants were monitored with GPS and heart rate monitors. Variables analysed were total time, total distance (m), relative total distance (m.min-1), total distance in velocity bands (m), and activity intensity (m.min-1). Mean and maximum heart rate were calculated as well as total time and percentage time spent in heart rate zones relative to HRmax. Players spent 52 ± 11 min in play. The total distance covered was 5986 ± 1105 m (116 ± 12 m.min-1) with 21.4 ± 6.8 m.min-1 of high intensity activity. Defenders covered the lowest relative total distance (p < 0.001) and attackers the highest (p < 0.001). Relative total distance in Q4 was 5% lower than in Q1and Q2 (p < 0.05) with moderate intensity exercise (8.1-15.5 km.h-1) being 11% lower in Q4 compared to Q1 and Q2. The mean HR and HRmax of players were 167 ± 10 and 194 ± 11 bpm respectively. Players had a lower mean HR in Q3 (164bpm) and Q4 (164bpm) compared to Q1 (169bpm) and Q2 (168bpm; p < 0.001). The current study provides novel data outlining the physical and physiological activity profiles of national-level male field hockey players across playing positions as well as quarters of play. The results highlight a need to consider positional differences when implementing a training programme for players at national level.

Knowledge about the emergency management of dental injuries among field hockey coaches.

BACKGROUND/AIM: Field hockey is frequently associated with oro-dental injuries. In such acute situations, appropriate management of the injury by coaches can contribute to a better clinical outcome and prognosis. Therefore, the aim of this study was to investigate the knowledge of hockey coaches in the Netherlands about the emergency management of dental injuries. MATERIAL AND METHODS: A 25-item questionnaire about the prevalence and management of oro-dental injuries was distributed amongst hockey coaches in the Netherlands. A sub-analysis was done regarding the knowledge on the management of dental injuries by using a 5-point scoring system. RESULTS: Two hundred and six hockey coaches participated in this survey. A small majority (53%) of the coaches knew the treatment of choice in the event of a permanent tooth injury. The median score of coaches' knowledge regarding management of oro-dental injuries was 3.0 (2.0-4.0) points. Coaches with a (para)medical training/occupation, and coaches with >10 years of experience had significantly higher scores compared with the other groups (p < .01 and p = .03, respectively). CONCLUSIONS: The knowledge level of hockey coaches in the Netherlands about oro-dental injuries needs to be improved, as many coaches are not aware of the appropriate first aid measures.

Incidence of penalty corner injuries in international field hockey.

Field hockey penalty corners (PCs) put players at potential risk for injuries. This study evaluated the incidence of PC-related injuries with special regards to head injuries. Video sequences provided by the Fédération Internationale de Hockey (FIH) of 295 matches in 11 elite field hockey tournaments (2015-2016) were analysed for overall injuries and PC-related injuries in detail. In total, 13.9% of all match injuries (49/352 injuries) occurred in relation to a PC, accounting for 7.1 PC-related injuries per 1000 player match hours (95% CI 4.4-9.9). There were 11 head injuries afflicting six defenders and five attackers. One head injury was related to a direct hit by a ball (drag flick). This study provides the first data on PC-related injuries in elite field hockey. The recorded numbers and mechanisms of PC-related injuries should be used as a baseline for further studies and potential rule adaptations.

Detrimental effects of prior self-control exertion on subsequent sporting skill performance.

The prior exertion of self-control has previously been shown to negatively affect physical performance, yet the effects on complex sporting skill performance have not been examined. Therefore, this study examined whether prior self-control exertion influences performance on a field hockey task, alongside measuring plasma cortisol concentration and attention as potential mechanisms to explain any effects. Following familiarization, 13 male hockey players (20 ± 1 years) participated in a randomized, order-balanced, crossover design. For the manipulation of self-control, participants completed an incongruent (self-control exertion trial) or a congruent (control trial) Stroop task. Skill performance was assessed using a field hockey skills task. Capillary blood samples, for the determination of plasma cortisol concentration, were taken at baseline, post-Stroop task, and post-field hockey skills task. Cognitive tests of attention (RVIP and Flanker tasks) were completed following the field hockey skills task. Participants made more errors in the latter stages of the field hockey skills task following self-control exertion (trial*time interaction, p = 0.041). Participants also made more errors on the RVIP task following self-control exertion (p = 0.035); yet the time taken to complete the hockey skills task, performance on the flanker task, and plasma cortisol concentrations were unaffected (all p > 0.05). Overall, these findings suggest that prior self-control exertion has detrimental effects on subsequent sporting skill performance (more errors made on the field hockey task), which may be explained by poorer sustained attention (lower accuracy on the RVIP task). This suggests that athletes should aim to avoid self-control exertion before a competitive match to optimize performance.

Wearable Technologies in Field Hockey Competitions: A Scoping Review.

The aim of this review is to investigate the common wearable devices currently used in field hockey competitions, and to understand the hockey-specific parameters these devices measure. A systematic search was conducted by using three electronic databases and search terms that included field hockey, wearables, accelerometers, inertial sensors, global positioning system (GPS), heart rate monitors, load, performance analysis, player activity profiles, and competitions from the earliest record. The review included 39 studies that used wearable devices during competitions. GPS units were found to be the most common wearable in elite field hockey competitions, followed by heart rate monitors. Wearables in field hockey are mostly used to measure player activity profiles and physiological demands. Inconsistencies in sampling rates and performance bands make comparisons between studies challenging. Nonetheless, this review demonstrated that wearable devices are being used for various applications in field hockey. Researchers, engineers, coaches, and sport scientists can consider using GPS units of higher sampling rates, as well as including additional variables such as skin temperatures and injury associations, to provide a more thorough evaluation of players' physical and physiological performances. Future work should include goalkeepers and non-elite players who are less studied in the current literature.

Effect of Changing Match Format from Halves to Quarters on the Performance Characteristics of Male University Field Hockey Players.

The study examined whether the performance characteristics of male university field hockey players differed when the match format was 2 × 35 min halves compared to 2 × 2 × 17.5 min quarters. Thirty-five male university field hockey players (age 21.2 ± 3.0 years, height 1.81 ± 0.07 m, body mass 75.1 ± 8.9 kg), competing at national level in the UK, were monitored over 52 matches played across the 2018-2019 (2 × 35 min halves) and 2019-2020 (2 × 2 × 17.5 min quarters) seasons using 15 Hz Global Positioning System units and heart rate monitors. Total distance, high-speed running distance (≥15.5 km·h-1), accelerations (≥2 m·s-1), decelerations (≤-2 m·s-1), average heart rate and percentage of time spent at >85% of maximum heart rate were recorded during both match formats. Two-level random intercept hierarchal models (Match-level 1, Player-level 2) suggested that the change in format from 2 × 35 min halves (2018-2019 season) to 2 × 2 × 17.5 min quarters (2019-2020 season) resulted in a reduction in total distance and high-speed running distance completed during a match (by 221 m and 120 m, respectively, both p < 0.001). As no significant cross-level interactions were observed (between season and half), the change from 35 min halves to 17.5 min quarters did not attenuate the reduced physical performance evident during the second half of matches (total distance: -235 m less in second half; high-speed running distance: -70 m less in second half; both p < 0.001). Overall, the findings suggest that the change in match format did alter the performance characteristics of male university field hockey players, but the quarter format actually reduced the total distance and high-speed running distance completed during matches, and did not attenuate the reduction in performance seen during the second half of matches.

Thickness change and deformation of custom-made mouthguards after two years of use by Bangladeshi field hockey players.

BACKGROUND/AIM: Sports mouthguards are effective devices that prevent dental trauma in sports activities. Players should change mouthguards on a regular basis because of thickness reduction and shape deformation. However, there is no guidance regarding the best timing to change mouthguards. The aims of this study were to analyze the thickness change and deformation of mouthguards after 2 years of use in Bangladesh field hockey players and to consider appropriate evaluation criteria. MATERIAL AND METHODS: Fifty-seven field hockey players belonging to the Bangladesh Sports Education Institute participated in this study. Participants were provided with double-layered mouthguards made of polyolefin-based material using a vacuum-forming machine. Mouthguards were fabricated using 2-mm-thick sheet as the first layer and 3-mm-thick sheet as the second layer. Players used the mouthguards for 2 years. Before and after using the mouthguards, the thicknesses of nine areas were measured. In addition, the lengths of five areas were used to analyze shape deformation. RESULTS: After 2 years, the thicknesses of all measured areas had significantly reduced, and the lengths had significantly increased. Thickness reduction of the posterior-occlusal and anterior-incisal areas and deformation of the posterior-buccal and posterior-palatal areas were significantly larger than those in other measured areas. CONCLUSIONS: Mouthguards should be changed on a regular basis to minimize thickness reduction and deformation. Occlusal and incisal thickness and length of the buccal-posterior area and the palatal-posterior area are factors to be considered in establishing guidelines regarding the timing of mouthguard change.

A systematic review of injuries in recreational field hockey: From injury problem to prevention.

The purpose of this study was to gather information from scientific literature related to all steps of Van Mechelen's "sequence of prevention" for injuries applied to youth and adult recreational field hockey players. A systematic review was conducted in Medline via Pubmed and in SPORTDiscus via EBSCOhost. Twenty-six original studies were included. Regarding injury incidence (step 1) results showed several overall injury incidence rates (youth: 1.47 per 1,000 Athlete Exposure (AE) time-loss (TL) injury up to 11.32 per 1,000 AE TL ánd non-time loss (NTL) injury, adults: 2.2 NTL injury per 1,000 AE, 15.2 injury per 1,000 hours of sports participation). Considering games and practices, most injuries were sustained in games (youth: 4.9, adults: 7.87 per 1,000 AE). Considering body parts, highest injury incidence rates were found in body parts in the lower extremities (youth: knee injuries in games (0.33 per 1,000 AE), adults: hamstring injuries in pre-season (0.75 per 1,000 AE)) and injuries in the head/face/eye (youth: 0.66 and adults: 0.94 head/face/eye, 0.71 head/face and 0.63 concussion per 1,000 AE). Regarding aetiology (step 2), no studies were found. Regarding the efficacy of available interventions (step 3 and 4), one study was found among youth players, describing a warm-up programme.

Maximum impact heights of currently used mouthguards in field hockey.

BACKGROUND/AIM: The effectiveness of mouthguards used in field hockey is unknown. The aim of this study was to compare the maximum impact heights between currently used mouthguards in field hockey to prevent dental injury. METHODS: Four boil-and-bite mouthguards (Dita, Shock Doctor, SISU, and Stag) and one custom-made mouthguard (Elysee) were tested for maximum impact height. A hockey ball was released in a tube from increasing heights onto plaster and polymethylmethacrylate (PMMA) dental models. Models were tested without mouthguard as a control. The experiment was repeated 10 times per mouthguard and for the control on each dental model. The maximum impact height for when the dental model broke was used to calculate the speed. The mouthguards and controls were compared. RESULTS: The maximum impact heights (median [25%-75%] in meters) onto plaster dental models were as follows: control 0.23 (0.15-0.25), Dita 0.35 (0.30-0.35), Elysee 0.45 (0.34-0.50), Shock Doctor 0.68 (0.60-0.74), SISU 0.23 (0.20-0.26), and Stag 0.35 (0.35-0.46). The maximum impact height for Shock Doctor was significantly higher than all other mouthguards and the control (all P < .05). The maximum impact heights onto PMMA dental models were as follows: control 2.00 (1.30-2.50), Dita 3.80 (2.65-6.95), Elysee 3.30 (2.30-4.20), Shock Doctor 6.20 (2.80-8.10), SISU 2.60 (1.90-3.15), and Stag 3.90 (1.25-5.15). The maximum impact height for Shock Doctor was significantly higher than for SISU, Stag, and the control (all P < .05), but did not differ significantly from Dita (P = .43) and Elysee (P = .12). CONCLUSION: Shock Doctor had the highest maximum impact height compared to the other mouthguards and appears to be the most effective mouthguard tested in this study.

Elite male field hockey players have symmetric isokinetic glenohumeral strength profiles, but show asymmetry in scapular muscle strength.

Shoulders of elite field hockey players are loaded continuously during play. However, shoulder girdle muscle performance in this population has never been examined yet. This study aimed to compare isokinetic shoulder girdle performance in elite male field hockey players to matched controls, with respect to strength, endurance and muscle balance. The complete male national field hockey team of Belgium (n = 25) was included and matched to a gender- and age-matched control group of healthy participants (n = 25). A Biodex system-4 dynamometer was used to measure glenohumeral and scapular muscle strength at 2 velocities in a concentric/concentric mode. With the main outcome measures being isokinetic strength values, peak force (protraction-retraction), peak torque (rotations), fatigue index and agonist/antagonist ratio's. Measurement results showed that elite male field hockey players were stronger than their matched controls, for both the rotational and the protraction-retraction movement. Concerning rotational strength, symmetrical findings were established, contrary to scapular strength, where side differences were noted. At low velocity, retraction peak force was higher on the dominant side. Protraction peak force was higher on the non-dominant side when measured at high velocity. In conclusion, elite field hockey players have a symmetrical rotational strength profile, in contrast to their scapular strength profile.

The inclusion of vibration therapy in rehabilitating a gastrocnemius tear: a case study in master athlete.

[Purpose] The aim of this case study was to determine if VT could be included into a rehabilitation programme by monitoring the progress of muscle pain, range of motion and muscle strength. [Participant and Methods] An international male master hockey player sustained a medial gastrocnemius 5 cm tear prior to the World Cup. VT was applied early in the rehabilitation programme where 9 sessions of VT were performed during the first 16 days. Other conventional rehabilitative exercises were included. [Results] Twenty-eight days post-injury the athlete returned to full playing. Calf pain had subsided by day 8 with a change of 12° in ankle dorsi flexion range of motion. Grade 5 calf strength was attained by day 16, which was equivalent to the unaffected limb's strength. There were no residual side effects of including VT into the rehabilitation programme and it did not compromise the athlete's recovery. [Conclusion] To ensure optimal loading of VT, 9 sessions were implemented and progressively increased; consequently, there was no detrimental effect on the rehabilitative process. The athlete reported no side effects of using VT and its ease and time efficient application has a role to complementing soft tissue injury rehabilitation.

Injuries in Dutch elite field hockey players: A prospective cohort study.

This study describes the prevalence, incidence density, severity, and nature of injuries in elite field hockey players over the Dutch 2015-2016 season. Eighty players answered a baseline questionnaire and were subsequently followed up every 2 weeks to report the hours spent on training/competition and experienced injuries, which were registered using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems. Of the 74 players included in the analysis, 52 (70%) reported 112 injuries. Eighty-seven injuries (78%) received medical attention, and 56 (50%) led to training/competition time-loss. Thirty-four injuries (30%) hampered players' availability to train and compete. Most of the injuries (74%) were not caused by any contact. The mean prevalence of injury was 29% (95% confidence interval [CI] 3-55) for all, 9% (95% CI 0-20) for acute, and 14% (95% CI 0-36) for overuse injuries. Players sustained 3.5 (95% CI 2.5-4.5) new acute injuries per 1000 hours of training and 12.3 (95% CI 7.6-17.0) per 1000 hours of competition. The median of the severity score was 28 from 100 (25%-75% interquartile range [IQR] 16-42) for all, 35 (IQR 23-53) for acute, and 21 (IQR 16-31) for overuse injuries. On average, 1 in 4 elite field hockey players experiences an injury within a 2-week period during the season. Although acute injuries are common, overuse injuries pose a comparable problem in elite field hockey. As injuries are a burden on players' health and may hamper performance and availability to train and compete, prevention is of great importance.

Dupuytren disease is highly prevalent in male field hockey players aged over 60†years.

BACKGROUND/AIM: Dupuytren disease is a fibroproliferative hand condition. The role of exposure to vibration as a risk factor has been studied with contradictory results. Since field hockey is expected to be a strong source of hand-arm vibration, we hypothesised that long-term exposure to field hockey is associated with Dupuytren disease. METHODS: In this cross-sectional cohort study, the hands of 169 male field hockey players (IQR: 65-71 years) and 156 male controls (IQR: 59-71 years) were examined for signs of Dupuytren disease. Details about their age, lifestyle factors, medical history, employment history and leisure activities were gathered. Prior to the analyses, the groups were balanced in risk factors using propensity score matching. The association between field hockey and Dupuytren disease was determined using a subject-specific generalised linear mixed model with a binomial distribution and logit link function (matched pairs analysis). RESULTS: Dupuytren disease was observed in 51.7% of the field hockey players, and in 13.8% of the controls. After propensity score matching, field hockey playing as dichotomous variable, was associated with Dupuytren disease (OR=9.42, 95% CI 3.01 to 29.53). A linear dose-response effect of field hockey (hours/week x years) within the field hockey players could not be demonstrated (OR=1.03, 95% CI 0.68 to 1.56). DISCUSSION: We found that field hockey playing has a strong association with the presence of Dupuytren disease. Clinicians in sports medicine should be alert to this less common diagnosis in this sport.

Epidemiology of injuries in outdoor and indoor hockey players over one season: a prospective cohort study.

OBJECTIVES: To determine the incidence and characteristics of hockey ('field hockey') injuries over the course of one outdoor and indoor season. Comparisons of female versus male players, outdoor versus indoor season and match versus practice were performed. METHODS: Female and male teams of the first, second, third, regional and youth divisions were recruited among a local hockey association in Northern Germany, and followed over an indoor and an outdoor season. Exposure times and location, type, severity and cause of injuries during practice and matches were documented by the coaches or medical staff and collected weekly. Prevalence and incidence rates were calculated. RESULTS: Of the 232 players (mean±SD age 20.7±4.7 years, 68.1% male, 31.9% first division), 84 players (36.2%) suffered 108 new injuries during the season. The overall incidence rate was 3.7 injuries per 1000 player hours (95% CI 3.0 to 4.4). The injury incidence was lower in practice (2.7 per 1000 player practice hours, 95% CI 2.0 to 3.3) than in matches (9.7 per 1000 player match hours, 95% CI 6.8 to 12.7), and was similar for female and male players as well as during the outdoor and the indoor season. Most injuries affected the lower limb (thigh, knee and ankle) and occurred without contact (58.3%). Severe injuries (n=34; 31.5%) were predominantly located at the knee and hand/finger. CONCLUSION: Hockey players have a high prevalence and incidence of injuries, especially at the lower limb.

Improvement of Elite Female Athletes' Physical Performance With a 3-Week Unexpected Disturbance Program.

CONTEXT: Sensorimotor training is commonly used in a rehabilitative setting; however, the effectiveness of an unexpected disturbance program (UDP) to enhance performance measures in uninjured elite athletes is unknown. OBJECTIVE: To assess the impact of a 3-wk UDP program on strength, power, and proprioceptive measures. DESIGN: Matched-group, pre-post design. SETTING: National sport institute. PARTICIPANTS: 21 international-level female field hockey athletes. INTERVENTION: Two 45-min UDP sessions were incorporated into each week of a 3-wk training program (total 6 sessions). MAIN OUTCOME MEASURES: 1-repetition-maximum strength, lower-limb power, 20-m running speed, and proprioception tests were performed before and after the experimental period. RESULTS: Substantial improvements in running sprint speed at 5-m (4.4 ± 2.6%; effect size [ES]: 0.88), 10-m (2.1 ± 1.9%; ES: 0.51), and 20-m (1.0 ± 1.6%; ES: 0.23) were observed in the UDP group. Squat-jump performance was also clearly enhanced when compared to the control group (3.1 ± 6.1%; ES: 0.23). Small but clear improvements in maximal strength were observed in both groups. CONCLUSIONS: A 3-wk UDP can elicit clear enhancements in running sprint speed and concentric-only jump performance. These improvements are suggestive of enhanced explosive strength and are particularly notable given the elite training status of the cohort and relatively short duration of the intervention. Thus, the authors would reiterate the statement by Gruber et al (2004) that sensorimotor training is a "highly efficient" modality for improving explosive strength.