Football incident analysis: a new video based method to describe injury mechanisms in professional football

Head Contact and Suspected Concussion Rates in Youth Basketball: Time to Target Head Contact Penalties for Prevention

OBJECTIVE

To compare game events, head contact (HC) rates, and suspected concussion incidence rates (IRs) in boys' and girls' youth basketball.

DESIGN

Cross-sectional.

SETTING

Canadian club basketball teams (U16-U18).

PARTICIPANTS

Players from 24 boys' and 24 girls' Canadian club basketball teams during the 2022 season.

ASSESSMENT OF RISK FACTORS

Recorded games were analyzed using Dartfish video analysis software to compare sexes.

MAIN OUTCOME MEASURES

Poisson regression analyses were used to estimate HCs [direct (HC1) and indirect (HC2)], suspected concussion IRs, and IR ratios (IRRs). Game event, court location, and HC1 fouls were reported.

RESULTS

Division 1 HC rates did not differ between boys (n = 238; IR = 0.50/10 player-minutes; 95% confidence interval [CI], 0.43-0.56) and girls (n = 220; IR = 0.46/10 player-minutes; 95% CI, 0.40-0.52). Division 2 boys experienced 252 HCs (IR = 0.53/10 player-minutes; 95% CI, 0.46-0.59); girls experienced 192 HCs (IR = 0.40/10 player-minutes; 95% CI, 0.35-0.46). Division 2 boys sustained higher HC1 IRs compared with Division 2 girls (IRR = 1.42; 95% CI, 1.15-1.74). Head contacts, rates did not differ between boys and girls in either Division. Suspected concussion IRs were not significantly different for boys and girls in each Division. Head contacts occurred mostly in the key for boys and girls in each Division. Despite illegality, HC1 penalization ranged from 3.9% to 19.7%. Head contact mechanisms varied across Divisions and sexes.

CONCLUSIONS

Despite current safety measures, both HCs and suspected concussions occur in boys' and girls' basketball. Despite the illegality and potential danger associated with HC, only a small proportion of direct HCs were penalized and therefore targeting greater enforcement of these contacts may be a promising prevention target.

Physical Contact and Suspected Injury Rates in Female versus Male Youth Ice Hockey: A Video-Analysis Study

OBJECTIVE

Canada's national winter sport of ice hockey has high youth participation; however, research surrounding female ice hockey is limited and the injury burden remains high. This study compared rates of head contact (HC), body checking (BC; high-intensity player-to-player contact), and suspected concussion between female and male youth ice hockey.

DESIGN

Cross-sectional.

SETTING

Game video-recordings captured in Calgary, Canada.

PARTICIPANTS

Ten female (BC prohibited) and 10 male (BC permitted) U15 elite AA (13-14-year-old) game video-recordings collected in the 2021 to 22 seasons and 2020 to 21, respectively.

ASSESSMENT OF RISK FACTORS

An analysis of player-to-player physical contact and injury mechanisms using video-analysis.

MAIN OUTCOME MEASURES

Videos were analyzed in Dartfish video-analysis software and all physical contacts were coded based on validated criteria, including HCs (direct [HC1], indirect [HC2]), BC (levels 4-5 on a 5-point intensity scale), and video-identified suspected concussions. Univariate Poisson regression clustering by team-game offset by game-length (minutes) were used to estimate incidence rates and incidence rate ratios (IRR, 95% confidence intervals).

RESULTS

The female game had a 13% lower rate of total physical contacts (IRR = 0.87, 0.79-0.96) and 70% lower rate of BC (IRR = 0.30, 0.23-0.39). There were however no differences in the rates of direct HC (IRR = 1.04, 0.77-1.42) or suspected concussion (IRR = 0.42, 0.12-1.42) between the cohorts. Although prohibited in the female game, only 5.4% of HC1s and 18.6% of BC resulted in a penalty.

CONCLUSIONS

The rates of HC1s and suspected concussions were similar across youth ice hockey. BC rates were lower in the female game, yet still prevalent despite being prohibited.

Development of a Standardised System to Classify Injury-Inciting Circumstances in Football: the Football Injury Inciting Circumstances Classification System (FIICCS)

BACKGROUND

A comprehensive examination of the sport-specific activities and circumstances being performed at the time of injury is important to hypothesise mechanisms, develop prevention strategies and inform future investigations. Results reported in the literature are inconsistent because inciting activities are reported using different classifications. Hence the aim was to develop a standardised system for the reporting of inciting circumstances.

METHODS

The system was developed using a modified Nominal Group Technique. The initial panel included 12 sports practitioners and researchers from four continents with respectively ≥ 5 years of experience working in professional football and/or conducting injury research. The process consisted of six phases: idea generation, two surveys, one online meeting and two confirmations. For answers to the closed questions, consensus was deemed achieved if ≥ 70% of respondents agreed. Open-ended answers were qualitatively analysed and then introduced in subsequent phases.

RESULTS

Ten panellists completed the study. The risk of attrition bias was low. The developed system includes a comprehensive range of inciting circumstances across five domains: contact type, ball situation, physical activity, session details, contextual information. The system also distinguishes between a core set (essential reporting) and an optional set. The panel deemed all the domains to be important and easy to use both in football and in research environments.

CONCLUSION

A system to classify inciting circumstances in football was developed. Given the extent of reporting inconsistency of inciting circumstances in the available literature, this can be used while further studies evaluate its reliability.

Higher Rates of Head Contacts, Body Checking, and Suspected Injuries in Ringette Than Female Ice Hockey: Time to Ring in Opportunities for Prevention

OBJECTIVE

Ringette and female ice hockey are high participation sports in Canada. Despite policies disallowing body checking, both sports have high injury and concussion rates. This study aimed to compare physical contact (PC), head contact (HC), and suspected injury and concussion incidence rates (IRs) in female varsity ringette and ice hockey.

DESIGN

Cross-sectional.

SETTING

Canadian ice arenas.

PARTICIPANTS

Eighteen Canadian female university ringette and ice hockey tournament/playoff games in the 2018-2019/2019-2020 seasons.

ASSESSMENT OF RISK FACTORS

Game video-recordings were analyzed using Dartfish video-analysis software to compare both sports.

MAIN OUTCOME MEASURES

Univariate Poisson regression analyses (adjusted for cluster by team, offset by game-minutes) were used to estimate PC, HC, and suspected injury IRs and incidence rate ratios (IRRs) to compare rates across sports. Proportions of body checks (level 4-5 trunk PC) and direct HC (HC 1 ) penalized were reported.

RESULTS

Analyses of 36 team-games (n = 18 ringette, n = 18 hockey) revealed a 19% lower rate of PCs in ringette than ice hockey {IRR = 0.81 [95% confidence interval (CI), 0.73-0.90]}, but a 98% higher rate of body checking [IRR = 1.98 (95% CI, 1.27-3.09)] compared to ice hockey. Ringette had a 40% higher rate of all HC 1 s [IRR = 1.40 (95% CI, 1.00-1.96)] and a 3-fold higher rate of suspected injury [IRR = 3.11 (95% CI, 1.13-8.60)] than ice hockey. The proportion of penalized body checks and HC 1 s were low across sports.

CONCLUSIONS

Body checking and HC 1 rates were significantly higher in ringette compared to ice hockey, despite rules disallowing both, and very few were penalized. These findings will inform future injury prevention research in ringette and female ice hockey.

Injury-Inciting Activities in Male and Female Football Players: A Systematic Review

BACKGROUND

A comprehensive examination of the sport-specific activities performed around the time of injury is important to hypothesise injury mechanisms, develop prevention strategies, improve management, and inform future investigations. The aim of this systematic review is to summarise the current literature describing the activities performed around the time of injury in football (soccer).

METHODS

A systematic search was carried out in PubMed, Web of Science, SPORTDiscus, and OpenGrey. Studies were included if participants were football players aged > 13 years old and the activities performed at the time of injury were reported together with the total number of injuries. Risk of bias was assessed using an adapted version of checklists developed for prevalence studies. The activities reported by the studies were grouped to account for inconsistent reporting, and the proportion of each injury activity was calculated. Data were not meta-analysed due to high heterogeneity of methods and classification criteria.

RESULTS

We included 64 studies reporting on 56,740 injuries in total. ACL injures were analysed by 12 studies, ankle/foot and knee injuries were analysed by five studies, thigh injuries were analysed by four studies, hip/groin injuries were analysed by three studies, and hamstring injuries were analysed by two studies. Five studies analysed more than one type of injury and 38 studies did not specify the type of injuries analysed. Running and kicking were the predominant activities leading to thigh and hamstring injuries. Changing direction and kicking were the predominant activities leading to hip and groin injuries and duels were the predominant activities leading to ankle injuries. Duels and pressing seem the predominant activities leading to ACL injuries, while results for other knee and general injuries were inconsistent.

CONCLUSIONS

A qualitative summary of the activities performed at the time of injury has been reported. The results need to be interpreted carefully due to the risk of bias observed in the included studies. If we are to meaningfully progress our knowledge in this area, it is paramount that future research uses consistent methods to record and classify injuries and activities leading up to and performed at the time of injury.

REGISTRATION

The protocol of this systematic review was registered at the Open Science Framework ( https://doi.org/10.17605/OSF.IO/U96KV ).

Video Analysis of Pectoralis Major Injuries in Professional Australian Football Players

Background:

There is little evidence regarding the mechanisms of pectoralis major (PM) injury and player outcomes in Australian Football League (AFL) players.

Purposes/Hypothesis:

The study aims were to investigate (1) the mechanisms of PM muscle injury in elite AFL players via video analysis and (2) the player profile, method of management, and clinical outcomes of the PM injuries sustained. We hypothesized that the majority of PM tears would occur in outer-range PM positions (hyperextension of the glenohumeral joint).

Study Design:

Case series; Level of evidence, 4.

Methods:

We analyzed video of the precipitating event for traumatic PM injuries during AFL competition or training over a 20-year period (2002-2021). The footage was analyzed by 4 experienced assessors, and the following were evaluated: mechanism of injury, injury variables (arm position, initial contact point, visual awareness, and use of taping), player characteristics (age at the time of injury, hand dominance, and history of injury), injury profile (location and size of tear), method of management (operative vs nonoperative), patient outcomes (time to return to full senior training/match play), and complication rates.

Results:

The mean ± standard deviation age of the players was 26.5 ± 3.1 years (range, 21-32 years). Overall, 22 PM injuries were identified in the AFL injury database for a rate of 1.1 per year; 16 of these injuries had accompanying video footage. We identified 3 mechanisms for PM injury: horizontal hyperextension (62.5%), hyperflexion-abduction (25.0%), and horizontal adduction (sustained tackling; 12.5%). The most common site of the tear was the insertion point of the sternocostal head (91.0%). Twenty players (91.0%) required surgical repair, with 75% undergoing surgery within 1 week (range, 0-26 weeks). The mean return to competition for the surgical repair group was 11.1 weeks (range, 8-15 weeks). The rerupture rate was 5.0% (1 repair; <4 weeks postoperatively in 2004).

Conclusion:

PM tears in elite male AFL players were due to 1 of 3 distinct mechanisms: horizontal hyperextension, hyperflexion-abduction, and horizontal adduction (sustained tackling). Players returned to play on average 11 weeks after injury. Knowledge regarding mechanisms of injury, player profile, and return-to-sport timelines is important for appropriate medical management and provides potential areas to target for prevention of PM injuries.

Distal biceps tendon ruptures occur with the almost extended elbow and supinated forearm - an online video analytic study

Background

Distal biceps tendon ruptures can lead to significant restrictions in affected patients. The mechanisms of injury described in scientific literature are based exclusively on case reports and theoretical models. This study aimed to determine the position of the upper extremities and forces involved in tendon rupture through analyzing video recordings.

Methods

The public YouTube.com database was queried for videos capturing a clear view of a distal biceps tendon rupture. Two orthopedic surgeons independently assessed the videos for the activity that led to the rupture, the arm position at the time of injury and the forces imposed on the elbow joint.

Results

Fifty-six video segments of a distal biceps rupture were included (55 male). In 96.4%, the distal biceps tendon ruptured with the forearm supinated and the elbow isometrically extended (non-dynamic muscle engagement) (71.4%) or slightly flexed (24%). The most common shoulder positions were adduction (85.7%) and neutral position with respect to rotation (92.9%). Most frequently a tensile force was enacted on the elbow (92.9%) and the most common activity observed was deadlifting (71.4%).

Conclusion

Distal biceps tendon ruptures were most commonly observed in weightlifting with a slightly flexed or isometrically extended elbow and forearm supination. These observations may provide useful information for sports specific evidence-based injury prevention, particularly in high performing athletes and individuals engaged in resistance training.

Level of evidence

Observational study.

Epidemiology of Injuries in National Collegiate Athletic Association Women's Ice Hockey: 2014-2015 Through 2018-2019

CONTEXT

The National Collegiate Athletic Association (NCAA) has sponsored women's ice hockey championships since 2001, and sponsorship has grown over time.

BACKGROUND

Routine examinations of injuries sustained by athletes are important for identifying and understanding patterns that can be used to inform sport safety practices.

METHODS

Exposure and injury data collected in the NCAA Injury Surveillance Program from 2014-2015 through 2018-2019 were analyzed. Injury counts, rates, and proportions were used to describe injury characteristics, and injury rate ratios were used to examine differential injury rates.

RESULTS

The overall injury rate was 5.89 per 1000 athlete-exposures; preseason injury incidence rose sharply during 2016-2017 through 2018-2019. Head/face injuries (15.2%), knee injuries (13.2%), and shoulder injuries (12.9%) were the most commonly injured body parts, and injuries were most often classified as contusions (18.9%), strains (18.7%), and sprains (15.5%). Concussion (11.9%) was the most commonly reported specific injury, and concussion rates notably increased during 2017-2018 through 2018-2019.

SUMMARY

Study findings were generally consistent with the existing epidemiological evidence. Injury incidence in preseason and the etiology of strains warrant further attention in this population.

Decision-making to stop or continue playing after football injuries - a systematic video analysis of 711 injury situations in amateur football

Scientific injury registration via video analysis is lacking in amateur football. The purpose of this study was to analyse match injury situations with a focus on the decisions made by players and referees after sustaining a football trauma. In a retrospective cohort study, traumatic injuries sustained in any of the 305 matches of the highest amateur level (4th league) in Germany in the 2015-16 season were assessed by means of video analysis and a standardised video protocol. In total, 711 traumatic incidents at 919 different body regions had been recorded. The three most frequently injured body regions were the ankles (34.1%), the head (17.5%) and the knees (17.0%). 90% (n = 156) of head injuries were direct contact injuries, this percentage was significantly higher than that of contact injuries on ankle (68.4%; p < 0.001) or knee (52.6%; p = 0.001). Referees decided on foul play significantly more often in case of knee injuries (57.1%; p = 0.002) or ankle injuries (64.5%; p < 0.001) than in head injuries (39.8%). Only 26.1% of players with a head injury opted for substitution, which was lower than after ankle (27.8%; p = 0.78) and knee injuries (34.0%; p = 0.13). In conclusion, amateur football is associated with a considerable number of injury situations that are followed by match interruptions and the substitution of players. Players and referees decided to continue playing more often after a head injury than after an injury to other body regions. An advanced education programme on the risks and management of head injuries in football is required to prevent long-term health consequences.

Evaluation of stoppage time due to field injuries in professional football games: do players really need medical help so often?

This study aimed to identify the incidence of stoppage time due to field injuries in professional football (soccer) games and to evaluate if the players involved really need medical care and whether team physicians deal with fake injuries. A total of 893 injury time-outs occurred leading to 956 treatments during 266 matches included in the study. The mean stoppage time was 88.7 ± 34.4 seconds. Less than one fifth of the injuries (17.4%) resulted in an impossibility to complete the game. The overall time-loss injury incidence which led players to miss the next game was 9.1/1000 match-hours (n = 80, 8.4% of all injuries). The players on teams in the lead at the time of the incident had significantly higher injury time-out incidence than players on teams who were losing (p < 0.05). Increasing the knowledge of team physicians, coaches, referees, and rule-makers about the medical needs of players during the game will help to identify the behaviour pattern of players.

Association of Skeletal Maturity and Injury Risk in Elite Youth Soccer Players: A 4-Season Prospective Study With Survival Analysis

BACKGROUND

The association between injury risk and skeletal maturity in youth soccer has received little attention.

PURPOSE

To prospectively investigate injury patterns and incidence in relation to skeletal maturity in elite youth academy soccer players and to determine the injury risks associated with the skeletal maturity status, both overall and to the lower limb apophysis.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

All injuries that required medical attention and led to time loss were recorded prospectively during 4 consecutive seasons in 283 unique soccer players from U-13 (12 years of age) to U-19 (18 years). The skeletal age (SA) was assessed in 454 player-seasons using the Fels method, and skeletal maturity status (SA minus chronological age) was classified as follows: late, SA >1 year behind chronological age; normal, SA ±1 year of chronological age; early, SA >1 year ahead of chronological age; and mature, SA = 18 years. An adjusted Cox regression model was used to analyze the injury risk.

RESULTS

A total of 1565 injuries were recorded; 60% were time-loss injuries, resulting in 17,772 days lost. Adjusted injury-free survival analysis showed a significantly greater hazard ratio (HR) for different status of skeletal maturity: early vs normal (HR = 1.26 [95% CI, 1.11-1.42]; P < .001) and early vs mature (HR = 1.35 [95% CI, 1.17-1.56]; P < .001). Players who were skeletally mature at the wrist had a substantially decreased risk of lower extremity apophyseal injuries (by 45%-61%) compared with late (P < .05), normal (P < .05), and early (P < .001) maturers.

CONCLUSION

Musculoskeletal injury patterns and injury risks varied depending on the players' skeletal maturity status. Early maturers had the greatest overall adjusted injury risk. Players who were already skeletally mature at the wrist had the lowest risk of lower extremity apophyseal injuries but were still vulnerable for hip and pelvis apophyseal injuries.

The Role of Deadlifts in Distal Biceps Brachii Tendon Ruptures: An Alternative Mechanism Described With YouTube Videos

BACKGROUND

The classic injury mechanism of a distal biceps brachii tendon rupture (DBBTR) is eccentric loading to the flexed elbow when the forearm is supinated.

PURPOSE

To determine alternative mechanisms of a DBBTR in powerlifting sports, particularly in deadlift competitions, with the use of YouTube videos.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

A search on YouTube was performed using the search terms "distal biceps tendon rupture" and "distal biceps tendon injury" combined with "competition," "deadlift," and "powerlifting." The videos underwent an evaluation for accuracy by 3 surgeons according to predetermined criteria. Type of sports activity, participant sex, side of the injury, and arm positions at the time of the injury were recorded.

RESULTS

Among the videos reviewed, 35 injuries were found appropriate for an evaluation. All participants were male. The majority of the injuries (n = 25) were observed during the deadlift. Only in 1 deadlift injury were both forearms in supination. In the remaining deadlift injuries (n = 24), all elbows were in extension, with 1 forearm in supination and the other in pronation. Among the deadlift injuries in the mixed-grip position, all ruptures occurred in a supinated extremity: 25% (n = 6) of ruptures occurred on the right side, and 75% (n = 18) of ruptures occurred on the left side; this was a significant difference (P = .014).

CONCLUSION

We described an alternative mechanism for a DBBTR, namely, eccentric loading to an extended elbow when the forearm is supinated during the deadlift. As all the ruptures occurred in a supinated extremity, holding the bar with both forearms in pronation may prevent or decrease the risk of ruptures during the deadlift.

Prospective analysis of craniofacial soccer incidents during FIFA competitions: an observational study

The aim of this prospective epidemiological study was to evaluate the occurrence of incidents involving the craniofacial region of soccer players during three official FIFA competitions. The craniofacial incidents were identified by video analysis of all 144 matches of two FIFA World Cups (2014/2018) and the 2017 FIFA Confederations Cup. Data collection included incident type, incident severity, site affected, incident cause and referee decision. The multivariate Poisson regression model was performed to analyze the associations between covariates. A total of 238 incidents were observed in the craniofacial region (1.6 incidents/match), representing a rate of 48.5 incidents per 1000 hours. At least 80.6% of the matches presented at least one incident, and, in more than 60%, the referee's decision was no foul. According to severity, 26.8% of the incidents were classified as having mild or high severity. Incidents involving lacerations or fracture presented higher severity compared with hits (IRR 3.45[95%CI: 1.89-6.30]). Head-to-head impacts showed an incidence of severe incidents twice as high as those involving upper extremities (IRR 2.01[95%CI:1.07-3.76]). A high number of craniofacial incidents were observed in the last FIFA competitions. Head-to-head impacts and lacerations or fractures were associated with higher incident severity.

Nine typical injury patterns in German professional male football (soccer): a systematic visual video analysis of 345 match injuries

AIM

We aimed to systematically analyse the videos of acute injuries in professional men's football and describe typical injury patterns.

METHODS

Injuries were registered with the German statutory accident insurance for professional athletes as part of occupational accident reporting. Following each season (2014-2017), video footage of the two highest divisions in German male football was searched for moderate and severe acute match injuries. Two raters then independently assessed the injuries for: game situation, player and opponent behaviour, referee decision, and injury mechanisms.

RESULTS

The total data set included 7493 acute injuries. Of these, 857 (11%) were moderate or severe match injuries. The video search yielded 345 (40%) clearly identifiable injuries and of those 170 (49%) were contact injuries. We describe nine typical injury patterns: one each for head and shoulder injuries, two for thigh and ankle, and three for knee injuries. The nine patterns are called: (1) Head-to-head injury. (2) Collision-and-fall shoulder injury. (3) Sprinter's thigh injury. (4) Perturbation-and-strain thigh injury. (5) Tackle knee injury. (6) Tackle-and-twist knee injury. (7) Non-contact knee injury. (8) Attacked ankle injury. (9) Collision-and-twist ankle injury. Thigh injuries occurred primarily in non-contact situations (44/81), mostly while the player was sprinting (23/44). Knee injuries were often caused by direct external impact (49/84)-mainly suffered by the tackler during a tackle (17/49).

CONCLUSION

The nine common injury patterns in football differed substantially in their mechanisms and causes.

Contact - but not foul play - dominates injury mechanisms in men's professional handball: a video match analysis of 580 injuries

AIM

We aimed to identify patterns and mechanisms of injury situations in men's professional handball by means of video match analysis.

METHODS

Moderate and severe injuries (absence of >7 days) sustained in competition in one of six seasons (2010 to 2013 and 2014 to 2017) in men's professional handball were prospectively analysed with a newly developed standardised observation form. Season 2013 to 2014 was excluded because of missing video material.

RESULTS

580 injuries were identified: 298 (51.4%) contact injuries, 151 (26.0%) indirect contact injuries and 131 (22.6%) non-contact injuries. Head (87.5%), hand (83.8%), shoulder (70.2%) and ankle (62.9%) injuries were mainly sustained during direct contact. Typical contact injuries included collision with an opponent's upper extremity or torso, and ankle injuries mainly consisted of foot-to-foot collisions. A large proportion (41.7%) of knee injuries were caused by indirect contact, whereas thigh injuries mainly occurred (56.4%) through non-contact mechanism. Wing (56.9%) and pivot (58.4%) players had the highest proportion of contact injuries, whereas backcourt players had a high proportion of indirect contact injuries (31.5%) and goalkeepers of non-contact injuries (48.9%). The injury proportion of foul play was 28.4%. Most injuries occurred in the central zone between the 6-metre and 9-metre lines (26.1%) and during the last 10 min of each match half (OR 1.71, p=0.016).

CONCLUSIONS

In men's professional handball in a league setting, contact - but not foul play - was the most common mechanism associated with moderate and severe injuries. Head, hand, shoulder and ankle injury were mainly sustained during direct contact.

Head impact exposure in youth football-Are current interventions hitting the target?

Restrictions on heading in youth football have been implemented in some countries to limit head impact exposure. However, current interventions remain poorly guided by evidence. Our objective was to quantify heading exposure in youth football, assessing the effects of sex and age. Football matches played during an international youth football tournament with no heading restrictions were directly observed, including players from both sexes (11-19 years). The elite senior level was included for comparison, using video analysis. All heading events were registered, classified, and assigned to individual players. Heading rates were calculated for each sex and age group. We observed a total of 267 matches, corresponding to 4011 player hours (1927 player hours for females, 2083 player hours for males). Males headed more frequently than females (2.7 vs 1.8 headers/player hour; P < .001). Heading rates increased with age (ANOVA, P < .001), approaching the elite senior level for players 16 years and older. There was substantial variation within teams for all age and sex groups, with the widest range (1-18 headers) observed for girls aged 19. Girls younger than 12 years had the lowest exposure, with an average of <2 players per team heading the ball, each with 1-2 headers. In conclusion, age and sex influence head impact exposure in youth football, and warrants careful consideration when introducing injury prevention measures. Males are more frequently exposed than females, heading rates increase with age, and there is substantial variation between players. Heading is a rare event in the youngest age groups, especially among females.

Harmful association of sprinting with muscle injury occurrence in professional soccer match-play: A two-season, league wide exploratory investigation from the Qatar Stars League

OBJECTIVES

To investigate the impact of physical efforts performed in the period preceding activity as a potential risk factor of muscle injury during match-play within a sample of professional soccer players.

DESIGN

Observational cohort study.

METHODS

Match load (running [>14.4-19.8km/h], high-speed running [>19.8-25.2km/h], sprinting [>25.2km/h], leading and explosive sprint type) averaged in 1-min and 5-min periods prior to an event or non event for 29 professional outfield soccer players. Conditional logistic and Poisson regression models estimated the relationship between load and injury for a 2 within-subject standard deviation in match load or 1-action increment in the number of sprinting activities, respectively. Associations were deemed beneficial or harmful based on non-overlap of the 95% confidence intervals against thresholds of 0.90 and 1.11, respectively.

RESULTS

An increment in sprinting distance [+2-SDs=11m] covered over a 1-min period (odds ratio [OR]: 1.22, 95%CI, 1.12 to 1.33) increased the odds of muscle injury.

CONCLUSIONS

Our study provides novel exploratory evidence that the volume of sprinting during competitive soccer match-play has a harmful association with muscle injury occurrence.

Mechanisms of acute adductor longus injuries in male football players: a systematic visual video analysis

BACKGROUND

Change of direction and kicking have been described as the main actions resulting in adductor longus injury. Video descriptions of inciting events are lacking.

OBJECTIVE

Perform a standardised visual video analysis of a series of acute adductor longus injuries in football.

STUDY DESIGN

Cross-sectional.

METHODS

Video footage was reviewed by players, and assessed independently by five sports medicine professionals. Inciting events were described and categorised using standardised scoring, including playing situation, player/opponent behaviour, movement and body positions.

RESULTS

Videos of acute adductor longus injuries in 17 professional male football players were analysed. Most injuries occurred in non-contact situations (71%), following a quick reaction to a change in play (53%). Injury actions were: change of direction (35%), kicking (29%), reaching (24%) and jumping (12%). Change of direction and reaching injuries were categorised as closed chain movements (59%), characterised by hip extension and abduction with external rotation. Kicking and jumping injuries were categorised as open chain (41%), characterised by a change from hip extension to hip flexion, and hip abduction to adduction, with external rotation.

CONCLUSION

Acute adductor longus injuries in football occur in a variety of situations. Player actions can be categorised into closed (change of direction and reaching) and open (kicking and jumping) chain movements involving triplanar hip motion. A rapid muscle activation during a rapid muscle lengthening appears to be the fundamental injury mechanism for acute adductor longus injuries.

Fractures in German elite male soccer players

BACKGROUND

Aim of this retrospective cohort study was to identify fracture epidemiology and off times after different types of fractures in German male elite soccer players from the first division Bundesliga based on information from the public media.

METHODS

Exposure and fracture data over 7.5 consecutive seasons (2009/10 until the first half of 2016/17) were collected from two media-based register (transfermarkt.de® and kicker.de®).

RESULTS

Overall, 357 fractures from 290 different players were recorded with an incidence of 0.19/1000 hours of exposure (95% CI: 0.14-0.24). Most fractures in German elite soccer players involved the lower extremities (35.3%), the head/face (30.3%) and the upper extremities (24.9%). The median off time after a fracture in German elite male professional soccer in 7.5 Season was 51.1 days (range 0-144). The number of fractures per 100 players per season decreased between 2009 and 2016. There was no significant difference in overall fracture incidence when comparing players at different position (P=0.11). Goalkeepers have a significantly (P<0.02) higher likelihood of suffering hand and finger fractures and they are significantly (P<0.03) less prone of suffering foot fractures, cranial and maxillofacial fractures (P<0.04). compared to outfield players.

CONCLUSIONS

This study can confirm that male professional soccer teams experience 1-2 fractures per season in German elite soccer. The incidence of fractures in elite German soccer players decreased between 2009 and 2016. The most fractures occur in the lower extremities and there is no difference in overall fracture risk for players at different playing positions. The information from our study might be of a great importance to medical practitioners, soccer coaches and soccer manager.

Observational Review and Analysis of Concussion: a Method for Conducting a Standardized Video Analysis of Concussion in Rugby League

Background

Several professional contact and collision sports have recently introduced the use of sideline video review for club medical staff to help identify and manage concussions. As such, reviewing video footage on the sideline has become increasingly relied upon to assist with improving the identification of possible injury. However, as yet, a standardized method for reviewing such video footage in rugby league has not been published. The aim of this study is to evaluate whether independent raters reliably agreed on the injury characterization when using a standardized observational instrument to record video footage of National Rugby League (NRL) concussions.

Methods

Video footage of 25 concussions were randomly selected from a pool of 80 medically diagnosed concussions from the 2013–2014 NRL seasons. Four raters (two naïve and two expert) independently viewed video footage of 25 NRL concussions and completed the Observational Review and Analysis of Concussion form for the purpose of this inter-rater reliability study. The inter-rater reliability was calculated using Cohen’s kappa (κ) and intra-class correlation (ICC) statistics. The two naïve raters and the two expert raters were compared with one another separately.

Results

A considerable number of components for the naïve and expert raters had almost perfect agreement (κ or ICC value ≥ 0.9), 9 of 22 (41%) components for naïve raters and 21 of 22 (95%) components for expert raters. For the concussion signs, however, the majority of the rating agreement was moderate (κ value 0.6–0.79); both the naïve and expert raters had 4 of 6 (67%) concussion signs with moderate agreement. The most difficult concussion sign to achieve agreement on was blank or vacant stare, which had weak (κ value 0.4–0.59) agreement for both naïve and expert raters.

Conclusions

There appears to be value in expert raters, but less value for naive raters, in using the new Observational Review and Analysis of Concussion (ORAC) Form. The ORAC Form has high inter-rater agreement for most data elements, and it can be used by expert raters evaluating video footage of possible concussion in the NRL.

Clinical benefit of the FIFA 11 programme for the prevention of hamstring and lateral ankle ligament injuries among amateur soccer players

Objective

To analyse the relationship between the implementation of ‘the 11’ protocol during the regular season in a men’s amateur soccer team and the rate of hamstring and lateral ankle ligament (LAL) injuries, and to estimate the clinical benefit of the programme according to the type of injury and the position field.

Methods

This cohort study was conducted in two different men’s amateur soccer teams. During two seasons, the exposed group (43 players) performed ‘the 11’ protocol twice a week, and the unexposed group (43 players) performed the regular training programme. All players trained three times per week for 1.5 hours per day. Data collection was performed for every 1000 hours of play.

Results

18 hamstring injuries (injury rate (IR) of 2.26 injuries/1000 training+competition hours) and 15 LAL injuries (IR of 1.88 injuries/1000) were registered in the exposed group. In the unexposed group, there were 25 LAL injuries (IR of 3.14 injuries/1000) and 35 hamstring injuries (IR of 4.39 injuries/1000). The number needed to treat to prevent one new case was 3.9 in LAL injuries, 3.31 in biceps femoris injuries and 10.7 in recurrent hamstring injuries.

Conclusions

‘The 11’ programme reduced the incidence of hamstring and LAL injuries in amateur players. According to the field position, the programme was effective for defenders and midfielders. In accordance with the type of injury, the exposed group had a lower risk of LAL, biceps femoris and hamstring injuries compared with those in the unexposed group.

Mechanisms and Factors Associated With Tackle-Related Injuries in South African Youth Rugby Union Players

BACKGROUND

The majority of injuries in rugby union occur during tackle events. The mechanisms and causes of these injuries are well established in senior rugby union.

PURPOSE

To use information from an injury database and assess video footage of tackle-related injuries in youth rugby union matches to identify environmental factors and mechanisms that are potentially confounding to these injuries.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

Injury surveillance was conducted at the under-18 Craven Week rugby tournament. Tackle-related injury information was used to identify injury events in match video footage (role-matched noninjury tackle events were identified for the cohort of injured players). Events were coded using match situational variables (precontact, contact, and postcontact). Relative risk ratio (RRR; ratio of probability of an injury or noninjury outcome occurring when a characteristic was observed) was reported by use of logistic regression.

RESULTS

In comparison with the first quarter, injury risk was greater in the third (RRR = 9.75 [95% CI, 1.71-55.64]; P = .010) and fourth quarters (RRR = 6.97 [95% CI, 1.09-44.57]; P = .040) for ball carriers and in the fourth quarter (RRR = 9.63 [95% CI, 1.94-47.79]; P = .006) for tacklers. Ball carriers were less likely to be injured when they were aware of impending contact (RRR = 0.14 [95% CI, 0.03-0.66]; P = .012) or when they executed a moderate fend (hand-off) (RRR = 0.22 [95% CI, 0.06-0.84]; P = .026). Tacklers were less likely to be injured when performing shoulder tackles (same side as leading leg) in comparison to an arm-only tackle (RRR = 0.02 [95% CI, 0.001-0.79]; P = .037). Ball carriers (RRR = 0.09 [95% CI, 0.01-0.89]; P = .040) and tacklers (RRR = 0.02 [95% CI, 0.001-0.32]; P =.006) were less likely to be injured when initial contact was made with the tackler's shoulder/arm instead of his head/neck.

CONCLUSION

The relative risk of tackle-related injury was higher toward the end of matches. Incorrect technique may contribute to increased injury risk. Implementing recovery strategies between matches, training safe and effective techniques, and improving levels of conditioning may counter the negative effects of fatigue. These findings may assist stakeholders in youth rugby to formulate injury prevention strategies and may improve the preparation of field-side medical staff for managing tackle-related injuries at these or similar tournaments.

Mechanisms of ACL injury in professional rugby union: a systematic video analysis of 36 cases

Background

The mechanisms of ACL injury in rugby are not well defined.

Aim

To describe the mechanisms of ACL injury in male professional rugby players using systematic video analysis.

Methods

36 cases from games played in top professional leagues and international matches were analysed. 5 analysts independently assessed all videos to record the estimated frame/time of initial ground contact, frame/time of ACL tear and a range of play specific variables. This included contact versus non-contact ACL injuries, injury timing, joint flexion angles and foot contact with the ground. 37 side-stepping manoeuvres from a control game were analysed to allow comparison of non-injury versus injury situations.

Results

57% of ACL injuries occurred in a contact manner. 2 main scenarios were identified: (1) offensive running and (2) being tackled, indicating that the ball carrier might be at higher risk of ACL injury. The majority of non-contact ACL injuries resulted from a side-stepping manoeuvre. In most non-contact cases, initial ground contact was through heel strike. Statistical assessment of heel strike at initial ground contact versus non-heel strike cases showed a significant difference in injury versus non-injury outcomes, with heel strike associated with higher injury risk. Non-contact ACL injuries had lower median knee flexion angles and a more dorsiflexed ankle when compared with a control group (10° vs 20°, p≤0.001 and 10° vs 0°, p=0.033 respectively).

Conclusions

Over half of ACL injuries in rugby in our analysis resulted from a contact mechanism. For non-contact injuries, lower knee flexion angles and heel-first ground contact in a side-stepping manoeuvre were associated with ACL injury.

Fracture epidemiology in male elite football players from 2001 to 2013: 'How long will this fracture keep me out?'

BACKGROUND

Determining fracture risk and rehabilitation periods after specific fractures in professional football is essential for team planning.

AIM

To identify fracture epidemiology and absences after different types of fractures in male professional football players.

METHODS

2439 players from 41 professional male teams in 10 countries were followed prospectively from 2001 to 2013. Team medical staff registered fractures, absences after fractures and player exposure.

RESULTS

364 fractures were recorded, with an incidence of 0.27/1000 h of exposure (95% CI 0.25 to 0.30). The incidence of traumatic fractures was 0.25 (0.22 to 0.27) and that of stress fractures was 0.03 (0.02 to 0.04). 45% of traumatic fractures and 86% of stress fractures affected the lower extremities. Absence after a fracture was 32 days (1-278) (median (range)), compared to that after a traumatic fracture of 30 days (1-278) and a stress fracture of 65 days (6-168) (p<0.001). Annual fracture incidence was stable during the study period (R(2)=0.051, b=-0.011 (95% CI -0.043 to 0.021)). Young players had a relative risk of 10.9 (3.3 to 35.6) of sustaining stress fractures compared to old players (p<0.01). The fracture incidence did not differ between individuals in different playing positions (p=0.10).

SUMMARY

A male professional football team can expect 1 to 2 fractures per season. There are more traumatic fractures than stress fractures; while most fractures affect the lower extremities, stress fractures yield longer absences than traumatic fractures and young players have more stress fractures than old players. There is no difference in risk among players at different playing positions.

Emergence of contact injuries in invasion team sports: an ecological dynamics rationale

The incidence of contact injuries in team sports is considerable, and injury mechanisms need to be comprehensively understood to facilitate the adoption of preventive measures. In Association Football, evidence shows that the highest prevalence of contact injuries emerges in one-on-one interactions. However, previous studies have tended to operationally report injury mechanisms in isolation, failing to provide a theoretical rationale to explain how injuries might emerge from interactions between opposing players. In this position paper, we propose an ecological dynamics framework to enhance current understanding of behavioural processes leading to contact injuries in team sports. Based on previous research highlighting the dynamics of performer-environment interactions, contact injuries are proposed to emerge from symmetry-breaking processes during on-field interpersonal interactions among competing players and the ball. Central to this approach is consideration of candidate control parameters that may provide insights on the information sources used by players to reduce risk of contact injuries during performance. Clinically, an ecological dynamics analysis could allow sport practitioners to design training sessions based on selected parameter threshold values as primary and/or secondary preventing measures during training and rehabilitation sessions.

Three distinct mechanisms predominate in non-contact anterior cruciate ligament injuries in male professional football players: a systematic video analysis of 39 cases

Background

Current knowledge on anterior cruciate ligament (ACL) injury mechanisms in male football players is limited.

Aim

To describe ACL injury mechanisms in male professional football players using systematic video analysis.

Methods

We assessed videos from 39 complete ACL tears recorded via prospective professional football injury surveillance between 2001 and 2011. Five analysts independently reviewed all videos to estimate the time of initial foot contact with the ground and the time of ACL tear. We then analysed all videos according to a structured format describing the injury circumstances and lower limb joint biomechanics.

Results

Twenty-five injuries were non-contact, eight indirect contact and six direct contact injuries. We identified three main categories of non-contact and indirect contact injury situations: (1) pressing (n=11), (2) re-gaining balance after kicking (n=5) and (3) landing after heading (n=5). The fourth main injury situation was direct contact with the injured leg or knee (n=6). Knee valgus was frequently seen in the main categories of non-contact and indirect contact playing situations (n=11), but a dynamic valgus collapse was infrequent (n=3). This was in contrast to the tackling-induced direct contact situations where a knee valgus collapse occurred in all cases (n=3).

Conclusions

Eighty-five per cent of the ACL injuries in male professional football players resulted from non-contact or indirect contact mechanisms. The most common playing situation leading to injury was pressing followed by kicking and heading. Knee valgus was frequently seen regardless of the playing situation, but a dynamic valgus collapse was rare.

Injuries in iran futsal national teams: a comparative study of incidence and characteristics

Background:

Futsal is a growing sport with lots of fans in many countries including Iran, but there are few papers in the literature which report injuries in top level futsal.

Objectives:

The aim of this study is to record and analyze the incidence and characteristics of injuries in Iran futsal national teams from March 2011 to September 2012.

Patients and Methods:

55 Iranian national futsal players participated in this prospective cohort study. Before entering the study, all players took part in Pre-Competition Medical Assessment (PCMA) in accordance with FIFA protocol. Team physicians recorded the injuries throughout the match and trainings in a special form which was designed for this purpose. Finally, data analysis was done with the SPSS software.

Results:

The total exposure time for all players was 24326 hours (21138 hours during training and 3188 hours during matches). During the study period, 32 of the 55 national players (58.2%) incurred 54 injuries (incidence rate = 2.22 injuries per 1000 players-hours). The incidence rate of injury in female players was significantly higher than male players (P = 0.001). The majority of injuries (85.2%) were located on the lower extremities. The ankle was the most frequent injury location (40.7%) and sprain was the most frequent type of injury.

Conclusions:

Injuries are common among futsal players and female players are more prone to injuries than male players. The ankle is the most frequent site and sprain is the most frequent type of injury among futsal players.

Etiology and Biomechanics of Tarsometatarsal Injuries in Professional Football Players: A Video Analysis

Background:

Tarsometatarsal (TMT) dislocations are uncommon yet debilitating athletic injuries, particularly in American football. To date, the mechanisms of athletic TMT dislocation have been described only anecdotally. This lack of information confounds the development of preventative countermeasures.

Purpose:

To use video analysis to provide direct, independent identification of the etiologic and mechanistic variables responsible for TMT dislocations in professional football players.

Study Design:

Case series; Level of evidence, 4.

Methods:

Sixteen professional National Football League players who sustained publicly reported TMT dislocations were identified. Publicly broadcast game footage of the plays in which injury occurred was reviewed by a panel of 5 biomechanists. Consensus was reached regarding the details surrounding injury, and a weighting was assigned to each detail based on the panel’s confidence.

Results:

Roughly 90% of injuries occurred while the injured player was engaged with or by another player, a detail that has heretofore been undocumented. Few injuries resulted from direct loading of either the foot or the ipsilateral limb; however, the injured foot was frequently subjected to axial loading from ground engagement with the foot in plantar flexion and the toes dorsiflexed. Injurious loading was often due to external rotation of the midfoot (86%). Fifteen of 16 injuries were season ending.

Conclusion:

TMT dislocations are frequently associated with engagement by or with a second player but infrequently caused by a direct blow to the foot. Axial loading of the foot, external rotation, and pronation/supination are the most common conditions during injurious loading.

Effectiveness of injury prevention programs on developing quadriceps and hamstrings strength of young male professional soccer players

Muscular strength is an important factor which is crucial for performance and injury prevention in most sports. The purpose of this study was to evaluate the effects of the FIFA’s Medical Assessment and Research Centre 11+ and HarmoKnee injury prevention programs on knee strength of young professional male soccer players. Thirty-six soccer players (age: 18.9 ± 1.4 years) were divided equally into three groups; the 11+, HarmoKnee and control groups. The programs were performed for 24 sessions. Hamstring and quadriceps strength was measured using the Biodex System 3 at 30°, 60° and 90° of knee flexion. The 11+ increased quadriceps strength in the dominant leg by 19.7% and 47.8% at 60°and 90° knee flexion, respectively, and in the non-dominant leg by 16%, 35.3% and 78.1 % at 30°, 60° and 90° knee flexion, respectively. The HarmoKnee group, however, showed increased quadriceps strength only at 90° i.e., by 85.7% in the dominant leg and 73.8% in the non-dominant leg. As for hamstring strength, only the 11+ group demonstrated an increment by 24.8% and 19.8% at 30° and 60° knee flexion in the dominant leg, and in the non-dominant leg, by 28.7% and 13.7% at 30° and 60° knee flexion, respectively. In conclusion, both warm-up programs improve quadriceps strength. The 11+ demonstrated improvement in hamstring strength while the HarmoKnee program did not indicate any improvement. We suggest adding eccentric hamstring components such as Nordic hamstring exercise to the HarmoKnee program in order to enhance hamstring strength.

Lower injury rates for newcomers to professional soccer: a prospective cohort study over 9 consecutive seasons

BACKGROUND

No study has investigated whether newcomers to professional soccer have a different injury rate than established players.

PURPOSE

The primary objective was to investigate whether being a newcomer to professional soccer influences injury rates. The secondary objective was to evaluate whether playing position and player age influence injury rates.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Twenty-six soccer clubs, with 1401 players, were followed prospectively over 9 consecutive seasons between 2001 and 2010. Club medical staff recorded time-loss injuries and soccer exposure on an individual level. Cox regression analyses were used to evaluate associations between time-loss injuries and time in professional soccer, playing position, and age.

RESULTS

In total, 6140 injuries and 797,389 hours of exposure were registered. A decreased general injury rate was observed for newcomers (n = 116) compared with established players (n = 3091) (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.61-0.99). In contrast, newcomers had a higher rate of fractures (rate ratio [RR], 1.77; 95% CI, 1.05-2.97), especially stress-related bone injuries (RR, 2.68; 95% CI, 1.08-6.69). Using goalkeepers as a reference, all outfield playing positions had significantly higher adjusted injury rates: defenders with an HR of 1.91 (95% CI, 1.64-2.24), midfielders with an HR of 1.78 (95% CI, 1.53-2.07), and forwards with an HR of 1.82 (95% CI, 1.55-2.14). Using players aged ≤21 years as a reference, the overall adjusted injury rate increased with age, with a peak injury rate among players aged 29 to 30 years (HR, 1.44; 95% CI, 1.24-1.68).

CONCLUSION

Newcomers to professional soccer had a lower general injury rate than established players but a higher rate of stress-related bone injuries. Being a goalkeeper was associated with lower injury rates than all outfield playing positions. Injury rates increased with age, a pattern that persisted after adjusting for playing position and match exposure.

Video incident analysis of concussions in boys' high school lacrosse

BACKGROUND

Boys' lacrosse has one of the highest rates of concussion among boys' high school sports. A thorough understanding of injury mechanisms and game situations associated with concussions in boys' high school lacrosse is necessary to target injury prevention efforts.

PURPOSE

To characterize common game-play scenarios and mechanisms of injury associated with concussions in boys' high school lacrosse using game video.

STUDY DESIGN

Descriptive epidemiological study.

METHODS

In 25 public high schools of a single school system, 518 boys' lacrosse games were videotaped by trained videographers during the 2008 and 2009 seasons. Video of concussion incidents was examined to identify game characteristics and injury mechanisms using a lacrosse-specific coding instrument.

RESULTS

A total of 34 concussions were captured on video. All concussions resulted from player-to-player bodily contact. Players were most often injured when contact was unanticipated or players were defenseless (n = 19; 56%), attempting to pick up a loose ball (n = 16; 47%), and/or ball handling (n = 14; 41%). Most frequently, the striking player's head (n = 27; 79%) was involved in the collision, and the struck player's head was the initial point of impact in 20 incidents (59%). In 68% (n = 23) of cases, a subsequent impact with the playing surface occurred immediately after the initial impact. A penalty was called in 26% (n = 9) of collisions.

CONCLUSION

Player-to-player contact was the mechanism for all concussions. Most commonly, injured players were unaware of the pending contact, and the striking player used his head to initiate contact. Further investigation of preventive measures such as education of coaches and officials and enforcement of rules designed to prevent intentional head-to-head contact is warranted to reduce the incidence of concussions in boys' lacrosse.

An online video investigation into the mechanism of elbow dislocation

PURPOSE

Acute elbow instability leading to dislocation is thought to be a spectrum initiated by an injury to the lateral stabilizing structures of the elbow. Previous cadaveric studies have shown elbow dislocations to occur in flexion. The purpose of this study was to analyze videographic evidence of the deforming forces and upper extremity position during elbow dislocations. We sought to corroborate previous biomechanics studies with in vivo observations.

METHODS

We included 62 YouTube.com videos with a clear videographic view of an elbow dislocation. Three senior elbow surgeons independently evaluated arm position at the time of dislocation, along with the suspected deforming forces at the elbow based on these positions.

RESULTS

Of the 62 visualized elbow dislocation events, the vast majority (92%) dislocated at or near full extension. The most common arm positions were forearm pronation (68%) with shoulder abduction (97%) and forward flexion (63%). The typical elbow deforming forces were a valgus moment (89%), an axial load (90%), and progressive supination (94%). We identified 4 discrete patterns of arm position and deforming forces.

CONCLUSIONS

Acute elbow dislocations in vivo occur in relative extension irrespective of forearm position, a finding distinct from previous cadaveric studies. The most common mechanism appears to involve a valgus moment to an extended elbow, which suggests a requisite disruption of the medial collateral ligament, the known primary constraint to valgus force. These videographic findings suggest that some acute elbow dislocations may result from acute valgus instability and therefore are distinct in nature and mechanism from posterolateral rotatory instability. This information could lead to improved understanding of the sequence of structural failure, modification of rehabilitation protocols, and overall treatment.

Video analysis of situations with a high-risk for injury in Norwegian male professional football; a comparison between 2000 and 2010

BACKGROUND

A recent study from Norwegian male professional football found that the risk of acute match injuries increased from 2002 to 2007.

OBJECTIVE

To compare the incidence of incidents with a propensity for injury, from the 2000 season to the 2010 season in Norwegian male professional football using video analysis.

METHODS

We conducted a video analysis of incidents in Norwegian professional football. An incident was recorded if the match was interrupted by the referee, and the player lay down for more than 15 s, and appeared to be in pain or received medical treatment. We also conducted a video analysis of all player-to-player contact situations occurring during 30 randomly selected matches.

RESULTS

A total of 1287 incidents were identified during the two seasons. The corresponding rate of incidents was 74.4 (95% CI 67.3 to 81.5) in the 2000 season and 109.6 (95% CI 102.3 to 116.9) in the 2010 season, a significant increase from 2000 to 2010 (rate ratio 1.47, 95% CI 1.31 to 1.66). We observed a significantly higher rate of opponent-to-player contact and non-contact incidents in the 2010 season, but no change in the proportion of fouls or sanctions awarded by the referee. The rate of player-to-player contact situations in both heading and tackling duels was lower during the 2010 season.

CONCLUSIONS

We found an increased rate of non-contact and opponent-to-player contact incidents in both heading and tackling duels in the 2010 season compared with 10 years earlier, even if there was no increase in the frequency of player-to-player contact situations.

Video incident analysis of head injuries in high school girls' lacrosse

BACKGROUND

Knowledge of injury mechanisms and game situations associated with head injuries in girls' high school lacrosse is necessary to target prevention efforts.

PURPOSE

To use video analysis and injury data to provide an objective and comprehensive visual record to identify mechanisms of injury, game characteristics, and penalties associated with head injury in girls' high school lacrosse.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

In the 25 public high schools of 1 school system, 529 varsity and junior varsity girls' lacrosse games were videotaped by trained videographers during the 2008 and 2009 seasons. Video of head injury incidents was examined to identify associated mechanisms and game characteristics using a lacrosse-specific coding instrument.

RESULTS

Of the 25 head injuries (21 concussions and 4 contusions) recorded as game-related incidents by athletic trainers during the 2 seasons, 20 head injuries were captured on video, and 14 incidents had sufficient image quality for analysis. All 14 incidents of head injury (11 concussions, 3 contusions) involved varsity-level athletes. Most head injuries resulted from stick-to-head contact (n = 8), followed by body-to-head contact (n = 4). The most frequent player activities were defending a shot (n = 4) and competing for a loose ball (n = 4). Ten of the 14 head injuries occurred inside the 12-m arc and in front of the goal, and no penalty was called in 12 injury incidents. All injuries involved 2 players, and most resulted from unintentional actions. Turf versus grass did not appear to influence number of head injuries.

CONCLUSION

Comprehensive video analysis suggests that play near the goal at the varsity high school level is associated with head injuries. Absence of penalty calls on most of these plays suggests an area for exploration, such as the extent to which current rules are enforced and the effectiveness of existing rules for the prevention of head injury.

Mechanisms and consequences of head injuries in soccer: a study of 451 patients

Object

The goal of this study was to evaluate the incidence and mechanisms of head injury during soccer games and to describe the results after spontaneous resolution of symptoms or after treatment.

Methods

In a retrospective study from 2005, records on 451 players from the German Soccer Association who had suffered various injuries were collected. The study used a questionnaire in which the player described the accident and the playing situation as well as the clinical course after trauma. This questionnaire also included information about the physical symptoms of the players and the length of their rehabilitation. Two groups were formed: one with head injuries (case group), and the other with injuries of other body parts (control group).

Results

Of the injuries reported, 108 (23.9%) were related to the head, 114 (25.3%) to the knee, 58 (13%) to the ankle, 56 (12%) to the calf, and 30 (7%) to the shoulder. The areas of the head most frequently involved were the facial and occipital regions. In the head injury group, the head duel was the most common playing action to lead to trauma. In those cases, the body part that hit the injured player was the elbow, arm, or head of the opponent. The most common playing situation was combat in the penalty area. The median hospitalization time after the trauma was 2 days for the case group and 5 days for the control group. The rehabilitation time for the case group was also shorter (median 6.5 days) than for the control group (median 30 days).

Conclusions

Trivial head injuries in soccer can have a long and complicated course. Nevertheless, the temporary disability is shorter in most cases than for players with injuries to other parts of the body. Modifying the rules of play would be necessary to reduce the incidence of head trauma.

Video analysis of the mechanisms of shoulder dislocation in four elite rugby players

BACKGROUND

Shoulder injuries are common in rugby, with the most severe match injury being shoulder dislocation and instability. A limitation of epidemiological studies is that the injury information is based on player interviews after the injury or reports from the medical staff. The objective of this study is to describe the specific injury mechanisms for shoulder dislocation using video recordings in a consecutive series of 4 elite male rugby players who sustained an episode of shoulder dislocation during an official match.

METHODS

Videotapes were reviewed to identify the mechanism of the injury. The incidents, including the play leading up to each incident, were analysed. A shoulder dislocation mechanism score was developed to describe the injury mechanism and the events leading up to the injury.

RESULTS

For all the athletes, player-to-player contact was responsible for the shoulder dislocation. Three of the four injuries resulted from trauma with the elbow in an extended position forcing the shoulder to exceed the limits of the normal range of motion, causing anterior shoulder dislocation. One injury resulted from trauma with the elbow in a flexed position and the direction of the injuring force along the longitudinal axis of the humerus causing posterior shoulder dislocation.

CONCLUSIONS

This study provides preliminary evidence that thorough video analysis can provide detailed information about the mechanisms of shoulder dislocation in elite rugby players. Knowledge of the common mechanisms of injuries in these athletes may potentially lead to improved sports technique to attempt to reduce the occurrence of shoulder dislocations. Further studies with a larger number of patients are required to better clarify the exact mechanism of shoulder dislocation in rugby players, and how these results may be applied in training and matches to prevent shoulder dislocation in elite rugby players.

Football officials activities during matches: a comparison of activity of referees and linesmen in European, Premiership and Championship matches

We compared the notational activity of 68 referees and 170 referee's assistants or linesmen officiating European matches from UEFA and the Champions League together with matches from the English Premiership and the English Championship competitions during the 2005/2006 football season using a computerised video system. We studied 328 games (14 European matches, UEFA and Champions league, 202 matches from the English Premiership and 112 from the English Championship). Referees covered a mean overall distance of 11.634 km, and assistants 6.508 km per match. Both referees and assistant referees covered significantly shorter distances jogging, running and high speed running in the second half compared to the first. There is a significant negative correlation between the distance covered and activity of officials compared with competition standard. Although we have demonstrated a negative correlation between distance covered and activity and competition standard, the physical activity across all competitions was intense and this reaffirms the high levels of fitness required by officials.

Prevalence and etiological factors of sport-related groin injuries in top-level soccer compared to non-contact sports

PURPOSE

Groin injuries and chronic pain are relatively common in soccer and other contact sports. Our aim was to define the gender-related frequency of both acute and chronic groin injuries in soccer compared to non-contact endurance sports.

METHODS

A 12-month study of 613 professional athletes was conducted in 2006. Premier league soccer players (77 males and 90 females) answered retrospectively 70 multi-choice questions of sport injuries. Factors related to groin injuries were compared with corresponding data of elite-level swimmers (n = 154), long-distance runners (n = 143) and cross-country skiers (n = 149).

RESULTS

In soccer, 125/167 players had 375 injuries (274 acute and 101 overuse injuries) and the number of acute injuries were 146/274 (53%) in males and 128/274 (47%) in females (p = 0.368). Acute groin injury was reported in 15/167 (9.0%) of elite soccer players compared to 3/154 (2.0%) in swimmers (p = 0.006) and 1.4% in both long-distance running (n = 2) and skiing (n = 2, p = 0.003). Male soccer players had acute groin injuries nearly three times more frequently than females. Chronic persistent groin pain was found in only one male and two female soccer players and no athletes in endurance sports.

CONCLUSIONS

Almost every tenth soccer player had an acute groin injury. Long-standing groin pain was not frequent in soccer and it was not found in non-contact endurance sport at the elite-level.

Injuries in women's soccer: a 1-year all players prospective field study of the women's Bundesliga (German premier league)

OBJECTIVE

To obtain precise information on injury patterns in the women's premier soccer league in Germany.

DESIGN

One-year, prospective, epidemiologic cohort study.

SETTING

Institutional level German Football Association.

PARTICIPANTS

All 254 players from all 12 women's premier league teams were included.

INTERVENTIONS

Base information by standardized personal interviews. Evaluation of all injury-associated medical data transmitted by standardized documentation forms.

ASSESSMENT OF RISK FACTORS

Injuries incidence rates (average, 95% confidence intervals) based on the exposure in matches and at practice.

MAIN OUTCOME MEASURES

All time loss diagnoses, number and context of injuries related to their anatomical localization, severity, and rehabilitation period were recorded.

RESULTS

All 254 players finished the study [average age, 22.8 years (16-35 years)]. Two hundred forty-six injuries amounted to an injury rate of 3.3 per 1000 hours (games, 18.5 per 1000 hours; practice, 1.4 per 1000 hours). Injury distribution: knee, 31.0%; ankle, 22.1%; thigh, 12.9%; and head, 7.1%. The seasonal peak was at the beginning of the competitive season. Injury rates doubled after the 60th minute. Twenty-nine percent of the injuries were severe, and 37% were moderate.

CONCLUSIONS

Female players suffer a high amount of head injuries and severe knee and ankle injuries. The most common single injury is a sprained ankle. Torn ligaments in the ankle and knee are the most common injuries that require a long recovery period. Most of the severe injuries (>30 days) are due to noncontact intrinsic mechanisms. Almost one-quarter of all injuries consist of exertion syndromes not yet correlated with certain seasonal periods.