bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrix metalloproteinase genes on chromosome 11q22 and the risk of anterior cruciate ligament (ACL) rupture
Authors: Posthumus M , Collins M , Van Der Merwe L , O'Cuinneagain D , Van Der Merwe W , Ribbans W J , Schwellnus M P , Raleigh S M 
Published: March 2011

BackgroundAnterior cruciate ligament (ACL) rupture is a complex disorder for which several risk factors, including genetic factors, have been established.ObjectiveAs matrix metalloproteinases (MMPs) are critical to ligament homeostasis and integrity, the primary aim of this study was to investigate if four selected polymorphisms within four MMP genes, which cluster on chromosome 11q22, associate with risk of ACL ruptures.Methods343 (138 individuals with ACL ruptures (ACL group) and 215 asymptomatic controls (CON group)) unrelated Caucasians were recruited for this case-control genetic association study. The ACL group included 54 participants with a non-contact mechanism of ACL rupture (NON- subgroup). All participants were genotyped using fluorescence-based assays, for the four selected functional polymorphisms; namely the MMP10 C/T rs486055, MMP1 1G/2G rs1799750, MMP3 G/A rs679620 and MMP12 A/G rs2276109 variants.ResultsWhen adjusted for sex, age and weight, the AG and GG genotypes of the MMP12 rs2276109 variant were significantly (p=0.030) under-represented among the NON-subgroups (14%), when compared to the CON group (26%). No other variants were significantly different between groups. In addition, when adjusted for the same confounders, the four variant haplotypes T-1G-A-A (CON 14%, ACL 9%, p=0.033) and C-2G-G-G (CON 14%, NON 5%, p=0.021) were significantly different between the CON group and the ACL group, as well as the CON and NON sub-group, respectively.ConclusionThis study reports for the first time that the chromosomal region 11q22 is associated with risk of ACL rupture. The genetic risk profile reported in this study, together with genetic risk factors previously associated, and those yet to be identified, should in the future be included in multifactorial models designed to reduce the incidence of ACL rupture within ‘at-risk’ populations. Further research is required to replicate these findings in an independent population.
Screening of asymptomatic elite youth hockey players: clinical and MRI exam
Authors: Philippon M J , LaPrade R F , Briggs K K , Stull J D 
Published: March 2011

BackgroundIce hockey players are reportedly at increased risk to suffer hip injuries. This may be due to repetitive hip positions during the ice hockey skate stride.ObjectiveTo determine if specific tests used during a screening program can identify youth hockey players who are at risk of acetabular labral tears due to femoroacetabular impingement (FAI).DesignProspective screening study.SettingClinical centre screened elite youth hockey players.Participants20 asymptomatic male (average age of 17.6 SD=0.5) ice hockey players who had signed IRB approved consent.Assessment of risk factorsParticipants underwent impingement testing, Flexion Abduction External Rotation (FABER) test, and range of motion and hip strength assessment prior to an MRI (3T) to determine hip alpha angle (AA) and labral pathology.Main outcome measurementsPositive clinical findings of impingement correlate with the presence of labral pathology and high AA.Results14 players had a positive clinical exam (+impingement test or+FABER test or decreased hip internal rotation). Players with a positive clinical exam had a significantly higher AA compared to those with no positive signs (68° vs 61°; p<0.025). Players with a positive clinical exam were 12.5 times (95% CI 1.1 to 143) more likely to have an AA 65° or greater. 12 of the 14 participants with a positive clinical exam also had partial acetabular labral tears.ConclusionWith this screening protocol, we were able to identify those patients with higher AA, which are considered at high risk. These players also demonstrated labral tears on MRI. We recommend that hip screening utilizing the impingement test, FABER test, and assessment of hip internal rotation be conducted as the initial screening of athletes with hip pain to assess for symptomatic FAI.
Injuries and terrain park feature use among snowboarders in alberta
Authors: Russell K , Meeuwisse W H , Nettel-Aguirre A , Emery C A , Ruest N , Wishart J , Rowe B H , Goulet C , Hagel B E 
Published: March 2011

BackgroundSnowboarding is a popular and risky winter sport. Snowboarders perform tricks on man-made features in terrain parks, which may introduce additional risk.ObjectiveTo determine snowboard terrain park feature-specific injury rates and risk factors.DesignCase-control study with exposure estimation.SettingA terrain park at a resort in Alberta, Canada, used for recreational and competitive snowboarding.ParticipantsCases were snowboarders injured in the terrain park who presented to the ski patrol or local emergency department (ED) (n=334). Controls were non-injured snowboarders using the terrain park (n=1262). The number of snowboarder-runs in the terrain park was recorded. Participants were recruited for two winter seasons.Assessment of risk factorsCases were identified from resort patient care records (PCRs) and ED logs. The PCRs captured demographic and environmental risk factors and injury assessment. Injured snowboarders were telephoned to determine exposure (feature used), listening to music and drugs/alcohol. Randomly selected controls were interviewed.Main outcome measurementsOverall and feature-specific injury rates (per 1000 runs) were calculated. Cases and controls were compared for risk factor prevalence using multiple logistic regressions to estimate adjusted OR (aOR) and 95% CI.ResultsThe overall injury rate was 0.75 injuries/1000 runs. Injury rates were highest on jumps (2.56/1000 runs), the half-pipe (2.56/1000 runs) and kickers (0.61/1000 runs). Compared with rails, the adjusted odds of injury were significantly higher on the half-pipe (aOR=9.6; 95% CI 4.8 to 19.3), jumps (aOR=4.3; 95% CI 2.7 to 6.8), mushroom (aOR=2.3; 95% CI 1.1 to 4.4) and kickers (aOR=2.0; 95% CI 1.3 to 3.1). The odds of severe injury (present to ED) versus minor injury did not differ by feature.ConclusionsThe injury rates and odds of injury were highest on features that facilitate aerial maneouvers. Resorts may consider marking all features to indicate difficulty and associated injury risk.
Training volume as a risk factor for the development of jumper's knee? data from the patellar tendinopathy cohort 2006–2010
Authors: Visnes H , Bahr R 
Published: March 2011

BackgroundPrevious studies on players with jumper's knee (cross-sectional studies and case-control studies) have found that symptomatic athletes were training more strength and more workouts per week compared with healthy asymptomatic players. Registration of training volume as risk factor for the development of jumper's knee is to our knowledge not previously done.AimStudy training volume as a risk factor for the developing jumper's knee.DesignCohort study.ParticipantsElite volleyball players at junior high school (Top Volley Norway) at Sand, Norway.MethodRegistration of training volume through weekly training diary on the internet, and interviews with the player and the coach. The jumper's knee diagnosis was based on a standardised clinical examination.ResultsA total of 140 symptom-free students were included (69 boys and 71 girls), with an mean observation time of 1.8 years. Of these, 28 developed jumper (22 boys and 6 girls). The jumper's knee group trained 20.1 ± 6.9 (SD) h per week, compared with the asymptomatic athletes 16.9 ± 6.9 h (p<0.001). The difference in the training workload was primarily related to indoor volleyball training, where the jumper's knee group trained 15.0 ± 3.0 h and the asymptomatic players 11.9 ± 3.8 h (p<0.001). The volume for other forms of training (volleyball, strength training, flexibility training and other training) were similar. For further analysis, the total training exposure (average hours per week) were divided into four groups. The training group 4 (21–28 h per week) have a significantly increased risk of developing jumper's knee. χ2test=8.57 gives p=0.01.ConclusionWe find that athletes who developed jumper's knee significantly trained more than athletes who remain asymptomatic. High training loads in the form of indoor volleyball training will therefore be an important risk factor for the developing jumper's knee.
Comparison of the effects of valgus loading and internal axial tibial torque on ACL strain during a simulated jump landing
Authors: Oh Y , Ashton-Miller J , Wojtys E 
Published: March 2011

BackgroundLittle is known about how much Anterior cruciate ligament (ACL) strain is increased by a valgus moment versus an internal axial tibial torque loading during a unipedal jump landing.ObjectiveTo test the (null) hypothesis that the anteromedial (AM) bundle ACL relative strain would not be significantly different under a simulated one-foot jump landing imposing an internally-directed tibial torque versus one imposing a valgus knee moment.Design12 cadaveric knees (mean (SD) age: 65.0 (10.5) years) were tested to study the effect of internally-directed tibial torque on the AM-ACL relative strain. Pretensioned quadriceps, hamstring and gastrocnemius muscle-tendon unit forces maintained an initial knee flexion angle. A compound impulsive test load (2*BW compression, flexion moment and internal tibial torque or valgus knee moment) was applied to the tibia while recording the 3-D knee loads and tibofemoral kinematics. AM-ACL relative strain was measured using a 3 mm DVRT. Each loading condition (ie, ‘internal’ or ‘valgus’ loading) was compared against ‘baseline’ loading condition under compression and flexion moment. Results were compared with those from Withrowet al. (2005) for 11 cadaveric knees of similar age tested on the same apparatus to investigate the effect of valgus knee loading on AM-ACL relative strain. The Wilcoxon Signed-Rank test was used to test the null hypotheses (p<0.05 being considered significant).SettingA cross-sectional, repeated measures, in vitro laboratory study.Assessment of risk factorsIndependent variables included the magnitude of the impulsive compressive force, flexion moment, and internal tibial torque or valgus knee moment.Main outcome measurementAM-ACL relative strain.ResultsNormalised peak AM-ACL relative strain increased 117% under internally-directed tibial torque (17 ± 4 N-m), whereas the corresponding value increased 30% under valgus knee loading (133 ± 29 N-m) (p=0.016).ConclusionInternal axial tibial torque increases AM-ACL relative strain more than a valgus load under a simulated jump landing.
No relationship between running related injuries and kinetic variables
Authors: Bredeweg S , Buist I 
Published: March 2011

BackgroundAlthough the benefits of running are well known, 19–79% of the runners get injured every year. Many risk factors are associated with the aetiology of running-related injuries, but still there is no consensus on the exact cause of running injuries. Kinetic variables, such as impact peak force, active peak force and the impact loading rate are scarcely studied in novice runners. Studies on the aetiology of stress fractures of the tibia showed conflicting results between kinetic factors and the development of stress fractures of the tibia.ObjectiveTo examine the effects of running kinetics on the incidence of running related injuries in novice recreational runners.DesignProspective cohort study. Kinetic variables were acquired from an instrumented treadmill with three force measuring transducers. Female participants ran at 2.2 m/s and 2.5 m/s and male participants at 2.5 m/s and 2.78 m/s. At each velocity the vertical ground reaction forces were measured, from which the kinetic variables were calculated.SettingNovice recreational runners.Participants98 male and 100 novice female runners, mean age 39.8 years and a body mass index of 25.4 were included in the study and were followed for 9 weeks during the training program.InterventionThe occurrence of a running related injury in a 9 week training program.Main outcome measurementA running related injury.ResultsThe incidence of running related injuries was 20.4%. Injured runners showed higher values on the active force peak (2.24 BW vs 2.11 BW) and higher values on the loading rate (92.5 BW/s vs 86.4 BW/s) compared to the non-injured runners. These differences however were not significant.ConclusionThis study showed no significant differences in kinetic variables between injured and non-injured novice recreational runners during a 9 week training program.
An analysis of impact forces in an active shoulder tackle in rugby
Authors: Usman J , McIntosh A S , Fréchède B 
Published: March 2011

BackgroundThe incidence of shoulder injury resulting from the tackle in rugby union football is high and the tackle is as well the main cause of injury. Little is known about the magnitude of tackle forces and influencing factors.ObjectiveTo measure the force applied to the shoulder in the tackle, the effect of shoulder padding, skill level, side of body, and player size.DesignRepeated measures design. In counterbalanced order, participants tackled a 45 kg tackle bag five times in the four conditions: dominant versus non-dominant sides; with and without shoulder pads.SettingCommunity level rugby football. The selection criteria were: (1) age 18–25 years old, (2) played at least 3 years of rugby, and (3) played at least a season of rugby within the last 3 years.Participants35 participants were recruited.InterventionsIRB approved shoulder pads.Main outcome measurementsMaximum impact force was measured with a custom built forceplate incorporated into a 45 kg tackle bag.ResultsThe overall average shoulder force was 1660 N. The average impact force for tackling without shoulder pads was 1684 N compared to 1635 N for wearers. Shoulder pads reduced the peak impact forces by 3% (p>0.05). There was a 6% difference in the average impact force between the dominant (1708 N) and non-dominant sides (1611 N). Tackle repetition was found to be a statistically significant factor as the impact forces reduced from the first tackle (1743 N) to the fifth tackle (1571 N) (p<0.05). No relationship was observed between player skill level and size.ConclusionShoulder pad performance needs to be improved. Although the shoulder force in the tackle is normally tolerated without injury, its magnitude is within the reported tolerance threshold range for sternoclavicular joint and glenohumeral joint. Fatigue may be an injury risk factor in the tackle.
Kinematics and kinetics of accidental ankle sprain in 3D motion analysis lab
Authors: Kristianslund E , Bahr R , Krosshaug T 
Published: March 2011

BackgroundAnkle sprain is among the most frequent sports injuries and a significant contributor to time lost from sports participation. The injury mechanism is traditionally described as an inversion trauma, but a detailed description including joint kinetics is lacking.ObjectiveTo provide an accurate description of an ankle sprain.DesignCase study.SettingSidestep cutting in 240 Hz motion analysis lab.PatientElite female team handball player (1.73 m, 63.7 kg, 22 years). Accidental grade 1 ankle sprain confirmed by orthopaedic surgeon.Assessment and outcomeAnkle kinetics and kinematics and ground reaction forces were compared between two normal trials and the injury trial.ResultsIn the injury trial we observed a sudden increase in ankle inversion (15° vs 4.9° and 4.8°) and ankle internal rotation (6.9° vs −1.2° and −3.6°) the first 50 ms. The injury trial centre of pressure had an increased lateral excursion after 50 ms (8.4 cm vs 3.3 and 3.0 cm). From 80 ms there was an increasing ankle inversion moment, reaching a peak of 72 Nm at 138 ms. At this time the ankle inversion angle had reached 33.1°, the ankle internal rotation angle was 53.7° and the ankle dorsiflexion was 26.5°. In the same period there appeared to be an attempted unloading of the foot, with a dorsiflexion of the ankle and reduced ground reaction force. The control trials displayed mainly eversion moment of the ankle throughout the stance phase, and joint angular deflections less than 6°.ConclusionThis study provides the most accurate and detailed description of ankle sprain dynamics to date. The injury involved inversion and internal rotation combined with an unloading of the foot that was initiated after approx 80 ms. The inversion moment likely caused the injury in the time period between 120 and 150 ms.
Injury risk for goalkeepers in norwegian male professional football
Authors: Strand E , Krosshaug T , Andersen T E 
Published: March 2011

BackgroundThe role of goalkeepers differs considerably from that of outfield players, but there are no previous studies specifically investigating their injury risk.ObjectiveTo investigate injury patterns, identify high-risk situations and describe injury mechanism for goalies.DesignProspective cohort study.Participants12 male goalkeepers from five of 14 teams in the Norwegian male professional league.MethodsInjury information and exposure data were collected for one competitive season, from April until mid-November 2008. Video recordings from 178 of 182 matches were analyzed to identify high-risk injury situations and to describe injury mechanisms.ResultsA total of 43 injuries were registered. The injury incidence was 27.9 per 1000 playing hours (95% CI 25.8 to 30.4) during matches, 23.6 (21.2 to 26.7) for specific goalkeeper training and 9.1 (8.3 to 10.1) during other football training (RR: 2.6, 95% CI 1.2 to 5.3 specific goalkeeper training compared to football training). Injuries to the upper extremities accounted for 36% of all injuries. The most frequent overuse injury location was the shoulder. Video analysis identified two high-risk situations during matches: 1) Duel in the airspace in front of goal after a cross pass, where the goalkeeper was hit in the stomach/chest by the opponent's shoulder/upper arm. 2) Duel where the goalkeeper collided with the opponent when coming out to save a backroom pass and the goalkeeper was hit in stomach/chest or the knee by the opponent's foot or knee. Video analysis did not reveal any typical mechanism of injury.ConclusionThis study provides novel information about injuries and high-risk situations for goalkeepers. Football goalies have higher injury risk during specific goalkeeper training compared to football training. Two high-risk situations for goalkeepers in matches were identified.
Evaluation of a national campaign in snow sports
Authors: Bianchi G , Brügger O , Niemann S , Furrer C 
Published: March 2011

BackgroundAround 15% of the 100 000 injuries that occur on ski slopes in Switzerland affect the head. Protective helmets can reduce the incidence of head injuries. Bfu and national partners carried out the campaign ‘1000 injuries per day. Protect yourself with a helmet’ to motivate skiers and snowboarders to use a snow-sport helmet.ObjectiveTo evaluate the success of the campaign objectives.SettingSkiers and snowboarders at 20 ski resorts in Switzerland.ParticipantsBefore, during and after the campaign, 19 740 skiers and snowboarders were observed; 8820 were interviewed.InterventionQuantitative surveys: observations and interviews. Qualitative surveys: document analysis, qualitative interviews, analysis of the media, group discussion.Main outcome measurementsA concept, process, impact and outcome evaluation was done by an external specialised evaluation agency.ResultsThe measures are appropriate to the target of increasing the rate of helmet use. The main elements (posters, television advertisement, helmet testing days) of the campaign were implemented as planned. Hazard awareness and consciousness of vulnerability improved between the 2007 and 2010 winter seasons. The target value of the criterion ‘lacking comfort’ couldn't be obtained. The helmet wearing rate has greatly increased. The results show a small correlation between campaign recognition and helmet use.ConclusionThe rate of helmet use, hazard awareness and consciousness of vulnerability increased considerably. However, the impact of the campaign on the increases is unclear. First, the rate of helmet use had already risen after the first year of campaigning. Second, studies have shown that campaigns may raise awareness but not achieve behavioural change. Third, there is only a small correlation between campaign recognition and helmet use. The campaign has supported and strengthened the effect of various factors that have promoted helmet use. However, the reasons for the increase in helmet use are unknown.
The swedish athletics study: various prevalence measures of musculoskeletal injury in élite athletics athletes
Authors: Jacobsson J , Timpka T , Ekberg J , Kowalski J , Nilsson S , Renström P 
Published: March 2011

BackgroundAthletics is one of the most popular global sports, but little is known of injury patterns among élite athletic athletes. Injury prevalence has been proposed to be the most valid measure of injury burden in sports where athletes practice long hours and are at risk for overuse problems.ObjectiveTo compare two different indicators of injury prevalence in athletics as measures of the injury burden among adult and youth élite athletics athletes.DesignCross-sectional epidemiological study using web-based data collection.SettingSwedish élite youth (U17) and adult athletics athletes. Data were collected in April 2009.Participants278 youth and adult athletes (91%) submitted a web-based questionnaire from an eligible study population of 301 athletes.Assessment of risk factorsAthlete's sex, age and anatomical body regions were assessed as risk factors.Main outcome measures1-year prevalence of musculoskeletal injuries causing at least 3 weeks of partial or complete absence from practice and competition; point prevalence of musculoskeletal injury.ResultsThe 1-year injury prevalence was 43.6%. Among the age groups, the prevalence was 48.1% for adult and 37.1% for youth athletes. The point prevalence of injury was 36.2%, 38% among adult athletes and 33% among youth athletes. Female youth athletes had a tendency towards higher 1-year (p=0.06) and point (p=0.025) injury prevalence than male youth athletes. There was no sex difference in injury prevalence among the senior athletes. A majority of the injuries (74% 1-year prevalence; 78% point prevalence) reported by the athletes were located to the lower extremities.ConclusionUsing either the point or 1-year retrospective window definition of prevalence, currently approximately 4 out of 10 Swedish élite athletic athletes have injuries that interfere with their performance of sports activities. Most injuries are located to the lower extremities. Prospective epidemiological studies investigating individual risk factors for athletic injuries are warranted.