bluuebunny/crossref_metadata_2025_split huggingface dataset:
FRICTION OF SPORTS FLOORS IN GERMAN MEN'S PROFESSIONAL BASKETBALL AND HANDBALL COMPETITIONS
Authors: Henke Thomas , Patrick Luig 
Published: August 2017

BackgroundWith regard to sliding friction sports floor manufacturers focus on comfort and performance aspects of athletes. In relation to safety aspects standardisation bodies rather concentrate on slippery than on dull floors. Thus, sliding friction coefficients from 0.4 to 0.6 (DIN 18032) are recommended. Biomechanical analyses have shown that higher sliding friction values produce higher joint moments and thereby probably increase the risk of acute and chronic injuries to the lower extremities.ObjectiveEvaluation of the floor conditions of sports floors used in German men's professional basketball and handball with specific regard to sliding friction.DesignPilot study.SettingTwo highest professional leagues in German men's basketball and handball.ParticipantsOverall, eight out of 53 sports floors used in regular league basketball and handball competition, two floors from first and second league respectively, were randomly picked for sample measurement of the floor conditions.Assessment of Risk FactorsDetermination of the friction coefficient by tribometric method (GTE, GMG 200) in four different areas of the playgrounds in each case.Main Outcome MeasurementsFriction coefficient in accordance to DIN 18032 (sports floors), DIN 51131, EN 13893.ResultsIn basketball the mean sliding friction coefficient was 0.41, ranging from 0.37 to 0.43. By contrast, in handball the observed mean value was 0.95, ranging from 0.78 to 1.06.ConclusionsIn view of sliding friction, all sample measured basketball floors were in accordance with the DIN 18032 but neither of the evaluated handball floors met these criteria. High sliding friction values were likely to result from intense resin use in handball. With regard to players' safety sports floor manufacturers, clubs and cleaning companies should be aware of this problem and develop targeted cleaning regimes for sports floors used in professional handball competitions. In handball, especially in view of resin use, rather than to the floor type.
CAN WE LIMIT TRAINING DAYS LOST DUE TO OSGOOD SCHLATTERS DISEASE IN JUNIOR SQUASH ATHLETES?
Authors: Horobeanu Cosmin , Jones Thomas , Johnson Amanda 
Published: August 2017

BackgroundHigh-intensity sports like Squash expose immature athletes to the risk of developing Osgood-Schlatter's (OSD) disease during critical periods of growth. Acute OSD episodes have been associated with changes in training load and recognized as a common cause of lost training days.ObjectiveTo investigate the influence of periodic OSD monitoring and any subsequent alterations in training load on the number of training days lost.DesignProspective data analysis over 2 seasons (80 weeks), repeated measures.SettingElite youth sports academy.Patients (or Participants)Highly-trained adolescent Squash athletes (n=9) who were identified as being “at risk” based on; previous episodes of OSD, chronological age (12–15 years) and maturity status.Interventions (or Assessment of Risk Factors)On a weekly basis a physiotherapist graded each athlete on a scale of 5 (“free of OSD symptoms”) to 1 (“unable to train”). The grading was based on clinical assessments including; pain level over the tibial tuberosity during palpation, functional movements, and strength assessments of the Quadriceps and Hamstrings. When an athlete was rated ≤3 coaching staff were advised to reduce the training load for the subsequent week. Training load was quantified using Edwards Training Impulse calculated from heart rate data.Main Outcome MeasurementsThe number of training days lost due to OSD. Any alterations in training load following a rating of ≤3.ResultsOver the intervention period there were 24 ratings of ≤3. Weekly training load following a rating of ≤3 was significantly lower than the average weekly load (245.4±231.2 Vs. 658.5±154.7 arbitrary units, P<0.001). Five training days lost due to OSD were recorded during the intervention period.ConclusionsPeriodic monitoring of OSD symptoms, with basic clinical tests, appear to alert the medical staff about potential acute onsets. Subsequent recommendations to reduce training load resulted in low training days lost due to OSD.
LOW BACK PAIN PAIN RISK FACTORS IN OLYMPIC CLASS SAILORS OCCUR PRE-REGATTA AND WITHIN THE REGATTA
Authors: Hunt Shawn , Roach Kathryn , Fiebert Ira 
Published: August 2017

BackgroundHiking activity during sailing involves the hips, trunk, head, and upper extremities held in sustained, unsupported positions over the side of a boat to stabilize it at an optimal angle to the water, preventing velocity loss and overturn. Hiking requires high forces generated by lower extremities and trunk, potentially producing high lumbar spine compression and shear loads linked to acute Low Back Pain.ObjectiveThis study examined if competitive sailors performing hiking were at increased risk of developing low back pain (LBP) compared to non-hikers over the course of an Olympic class regatta.DesignProspective Cohort.SettingWorld Cup Regatta.Patients (or Participants)172 Olympic class sailors completed a questionnaire concerning sailing activities, previous history of, and new LBP following a 6-day regatta. 152 subjects without LBP at the beginning of the regatta were classified as exposed (hikers) and unexposed (non-hikers) and new LBP cases were recorded for both groups.Interventions (or Assessment of Risk Factors)Relative risk ratios (RR) and CI95%were calculated compared risk of new LBP in hikers and non-hikers.A priorihypothesis tested: hiking sailors are at increased risk for incident LBP versus non-hikers.Main Outcome MeasurementsSelf-report LBP limiting sailing.ResultsTwenty-two subjects reported new LBP, 18 from hiking exposure group. Exposed (n=84) and unexposed (n=68) were no different in demographic/anthropometric variables across exposure and disease groups. Boat/equipment unloading time differences persisted across groups (P=0.0016, P=0.0022 respectively). Hikers' raw RR was 3.64 (CI 95% 1.29,10.26) times greater than non-hikers' for developing new LBP. Hikers' risk controlled for unloading time levels yielded an adjusted RR of 2.73 (CI 95% 1.05, 7.08). Hikers exposed to high unloading levels (>2 hours) RR was 8.3 (CI 95% 1.05, 65.76) versus non-hikers.ConclusionsHiking and unloading forces may be risk factors for LBP prior to and during Olympic class regattas. Further study recommended.
GOOD EYESIGHT – A BASIC PRECONDITION FOR SAFETY AND PERFORMANCE IN SPORTS
Authors: Jendrusch Gernot , Oertzen-Hagemann Vanessa 
Published: August 2017

BackgroundGood eyesight is a basic precondition for safety but also for performance in sports. Vision has a crucial importance for movement control and balance regulation. Vision helps anticipating, e.g. fast movements in ball games as well as potential accident risks e.g. in one-on-one-situations in football or handball. Investigations show that about 20% of all elite athletes exert their sport ametropic. Nevertheless regular and meaningful visual tests for the analysis of the multidimensional visual performance and the detection of ametropia are only integrated in the health diagnostics of a few sports.ObjectiveAim of the study was to analyze current data of German elite athletes concerning ametropia or different parameters of visual performance; especially considering parameters that are also tested by optometrists or ophthalmologists.ParticipantsThe study is based on a retrospective analysis of cross-sectional eye test data from different national teams (n=553; age: 21.0±4.0 years) which were collected in the annual routine health check in the last three years (2013–2015).ResultsAbout 27.5% of athletes use visual aids in daily life, whereas 33.3% of athletes with ametropia are practicing their sports without an optical correction. The median of the (monocular) visual acuity is about 1.85 for men and 1.80 for women (maximum-values considerably above 2.50). Altogether there are 22.6% athletes that are detected as ametropic and thus in need of correction.ConclusionsAll results mentioned and further literature searches show that good eyesight is important from the perception physiology and injury prevention point of view. Visual acuity, contrast sensitivity, depth and motion perception etc. have a significant influence on performance and quality of sports – depending on the specific demands of the discipline. Visual function tests should be included in health diagnostics in order to be able to detect and subsequently correct visual deficiencies at an early stage.
SELF-REPORTED INJURY MECHANISMS IN CLIMBERS
Authors: Jones Gareth , Woodard Cara , Sharples Paul , Johnson Mark 
Published: August 2017

BackgroundClimbing is an increasingly popular sport worldwide. However relatively little is known about the mechanisms of injury sustained by climbers.ObjectiveTo investigate mechanisms of injury in a representative sample of British climbers.DesignRetrospective cross-sectional study.SettingOnline survey of active climbers.Patients (or Participants)369 active climbers (men n=307, mean±SD, age=37.66 ±14.38 years; Women n=62, mean ±SD, age=34.63 ±12.19 years).Interventions (or Assessment of Risk Factors)Epidemiological incidence proportion (IP) and mechanism of injury.Main Outcome MeasurementsInjuries that resulted in medical intervention and/or withdrawal from participation for ≥1 day.ResultsOf 369 climbers surveyed, 299 sustained at least 1 injury in the last 12 months resulting from climbing. The IP was 0.810 (95% CI: 0.770–0.850). Thus the average probability of sustaining at least one injury was 81% (95% CI: 77–85). The total number of injuries sustained was 1088 providing a clinical incidence of 2.95 injuries per climber. 94 climbers sustained an acute injury as a result of impact with the climbing surface and/or ground, 212 climbers sustained an injury resulting from chronic overuse and 166 climbers sustained injuries resulting from a non-impact acute trauma. The average probabilities of sustaining injury per mechanism were: impact injury 25.5% (95% CI: 23.2–27.8); acute non-impact injury 45.1% (95% CI: 42.5–47.7) and chronic overuse injury 57.5% (95% CI: 54.9–60.1). Injury from chronic overuse was positively associated with indoor lead operating standard (P=0.007), bouldering operating standard (P< 0.001) and bouldering frequency (P< 0.001). The most common injury site was the fingers with 180 participants (60%) sustaining at least one finger injury. 85 participants sustained at least 1 chronic overuse reinjury.ConclusionsThe most commonly reported injury mechanism was chronic overuse. The most common site was the fingers. Chronic overuse injuries due to repetitive loading may have been historically preceded by a non-impact acute trauma.
THE PSYCHOLOGICAL IMPACT OF ELECTROCARDIOGRAM SCREENING IN NATIONAL COLLEGIATE ATHLETIC ASSOCIATION ATHLETES
Authors: Asif Irfan , Annett Scott , Ewing Alex , Abdelfattah Ramy , Rothmier Justin , Harmon Kimberly , Drezner Jonathan 
Published: August 2017

BackgroundCardiovascular screening is a means to prevent sudden cardiac death in athletes. The American Heart Association has raised concerns that false-positive electrocardiogram (ECG) screening may cause undue anxiety.ObjectiveDetermine the psychological impact of false-positive ECG screening in NCAA athletes and to stratify experiences based on screening outcome, race, gender, sport, and division of play.DesignProspective, multi-site investigation.SettingSeven NCAA institutions.Patients (or Participants)1192 student-athletes (55.4% male, median age 19 years, 80.4% Caucasian).Assessment of Risk FactorsPre-participation screening with a standardized history, physical examination, and ECG.Main Outcome MeasurementsPre- and post-screen validated assessments for health attitudes, anxiety, and impact of screening on sport.Results96.8% of athletes had a normal cardiovascular screen (96.8%), 2.9% had a false-positive ECG, and 0.3% were diagnosed with a serious cardiac condition. Prior to screening, 4.5% worried about cardiac risk and 70.1% preferred knowing about an underlying condition, rather than play sports without this knowledge. There was no difference in anxiety described by athletes with a normal versus false-positive screen (p=0.369). Reported anxiety levels during screening also did not differ when analyzed by different gender, race, division of play, or sport. Athletes with normal and false-positive screens had similar levels of satisfaction (p=0.714) and would recommend ECG screening to other athletes at similar rates (p=0.322). Compared to athletes with a normal screen, athletes with false-positive results also reported feeling safer during competition (p>0.01). In contrast, athletes with false-positive screens were more concerned about the possibility of sports disqualification (p<0.001) and the potential for developing a future cardiac condition (p<0.001).ConclusionsFalse-positive results from ECG screening do not cause excessive anxiety in NCAA athletes. Further understanding of athlete experiences could better prepare the practicing physician on ways to counsel athletes with an abnormal ECG in order to address additional concerns.
MECHANISMS OF ANTERIOR CRUCIATE LIGAMENT INJURIES IN VOLLEYBALL
Authors: Karita Yukiko , Kimura Yuka , Yamamoto Yuji , Naraoka Takuya , Sasaki Shizuka , Miura Kazutomo , Tsuda Eiichi , Ishibashi Yasuyuki 
Published: August 2017

BackgroundKnee injuries were common in volleyball players, and ACL injury is a serious injury for athletes.ObjectiveThe purpose of this study was to investigate the mechanism of ACL injury in volleyball players using a questionnaire.DesignResearch study using a questionnaire.SettingVolleyball players who had ACL reconstruction at our institution.PatientsTwenty-five females and 1 male (mean age; 24.6±11.0 years-old) volleyball players who ruptured their ACL during volleyball and underwent ACL reconstruction.Assessment of Risk FactorsThey were asked about their position, dominant hand defined as the spiking hand, side of injury, event during which the injury occurred (game or practice), the circumstance of injury (the situation in which the injury occurred, the specific motion at the time of injury) and player position and court location where the injury occurred.ResultsThere were 19 wing spikers (left 13, right 6). Twenty-four players were right-handed and 2 players were left-handed, and 23 players injured the knees opposite to dominant hand. The 65.4% of injuries were prevalent during game. Twenty players (76.9%) were injured during spiking. Twenty-one players (80.8%) receive injured during landing, and 16 of them injured with single-leg landing after spiking. Most of ACL injuries (84.6%) occurred in front of the attack line near the net.ConclusionsSingle leg landing after spiking close to the net was the most common cause of injury, and most of wing spikers injured the knee opposite to their dominant hand. It suggests that wing spikers need to consider prevention strategies focusing on spiking movement.
THE EPIDEMIOLOGY OF US HIGH SCHOOL FOOTBALL (SOCCER) INJURIES, 2005–06 THROUGH 2013–14
Authors: Khodaee Morteza , Currie Dustin W , Asif Irfan , Comstock R. Dawn 
Published: August 2017

BackgroundDespite the worldwide popularity of football, research on epidemiology of high school injury is sparse.ObjectiveTo describe high school football injury rates and patterns by type of athletic exposure and gender.DesignThis descriptive epidemiologic study used retrospective analysis of high school sports injury data from a multi-year US surveillance program capturing data from a large national cohort of schools.SettingAnnually, this prospective surveillance study recruits 100 US high schools with National Athletic Trainers' Association affiliated, athletic trainers to report exposure and injury data for athletes participating in school-sanctioned high school sports.ParticipantsStudent football players from these nationally representative high schools from 2005–06 through 2013–14.Assessment of Risk FactorsIndependent variables included gender, mechanism of injury, playing position, and field location.Main Outcome MeasurementsRates and patterns of football-related injuries.ResultsOverall 6154 football injuries occurred during 2,985,991 athlete exposures (AEs); injury rate of 2.06 per 1000 AEs. This corresponded to a national estimate of 3,381,189 US high school football-related injuries. Injury rates were higher in girls (2.33) than boys (1.83) (RR=1.27, 95% CI 1.21–1.34). Player-player contact more commonly resulted in competition injuries (injury proportion ratio [IPR]=2.87; 95% CI 2.57–3.21), while noncontact mechanisms were more common among practice injuries (IPR=2.10; 95% CI 1.86–2.38). Most injuries occurred to midfielders (37.6%), followed by forwards (28.9%), and defenders (23.6%).. The most common activities leading to injuries were general play (24%), defending (13%), and chasing a loose ball (11%). Injury patterns were similar between genders with respect to position played and location on the field at the time of injury.ConclusionsHigh school football injury rates vary by gender and type of exposure while injury patterns are more similar across genders. These findings should drive additional research into development, implementation, and evaluation of targeted injury prevention efforts.
THREE-DIMENSIONAL IN-VIVO SCAPULAR KINEMATICS AND SCAPULOHUMERAL RHYTHM: A COMPARISON BETWEEN ACTIVE AND PASSIVE MOTION
Authors: Kim Doo-Sup 
Published: August 2017

BackgroundThis study set out to offer a three-dimensional description of scapular kinematics and scapulohumeral rhythm (SHR) of healthy subjects during arm elevation and lowering, as well as to compare and analyse the differences between active and passive motion of the shoulder.MethodsThe study examined the shoulders of ten healthy males (mean age: 23.5 years). The shoulders of the ten healthy participants were elevated and lowered while fluoroscopic images were taken, and three-dimensional bone models were created from 2D to 3D using model registration techniques. The Euler angle sequences of the models' scapular kinematics and SHR were compared during active and passive shoulder motion.ResultsThe scapula presented three-way movements of upward rotation, posterior tilting, and external rotation during arm elevation and lowering. During arm elevation, upward rotation showed a statistically significant difference between active and passive shoulder movements (p<0.05). Upward rotation between 45° and 90° showed a statistically significant difference (p<0.05). The scapular posterior tilting from the active motion resulted in more tilting in the high-degree range of motions. Additionally, statistically significant differences were found between active and passive motion (p<0.05). There was no statistically significant difference between the two groups during external rotation. However, during arm lowering, the scapular upward rotation showed a statistically significant difference between active and passive motion (both p<0.05).ConclusionsIn healthy subjects, scapular kinematics showed a statistically significant difference between active and passive motion during elevation in the higher range of motion, but not during lowering. In terms of upward rotation, active shoulders rotated more upward during arm elevation. There was more upward rotation in active shoulders during arm elevation. With regard to passive motion, there was more posterior tilting during arm elevation. The scapular kinematics of upward rotation and posterior tilting showed a linear rotation during arm lowering.
HIGH PREVALENCE OF SUBSTANTIAL SHOULDER PROBLEMS AMONG ELITE ADOLESCENT HANDBALL PLAYERS: THE KAROLINSKA HANDBALL STUDY
Authors: Asker Martin , Holm Lena W , Källberg Henrik , Waldén Markus , Skillgate Eva 
Published: August 2017

BackgroundRecent studies report a high prevalence of shoulder problems in senior team handball players but studies in adolescent players are lacking.ObjectiveTo measure the season prevalence of substantial shoulder problems (SSP) in elite adolescent handball players.DesignLongitudinal cohort study with weekly online follow-ups.SettingElite adolescent male and female handball players at handball-profiled high schools in Sweden.Participants471 (54% females, mean age 16) were recruited from 10 of 15 national handball-profiled high schools.Assessment of Risk FactorsThe prevalence of SSP, stratified by age, was assessed through repeated online questionnaire data.Main Outcome MeasurementsSeason prevalence of SSP during the previous handball season was measured during the pre-season (baseline), and was studied prospectively during the current season via weekly reports using the OSTRC Overuse Injury Questionnaire. SSP was defined as problems leading to moderate or severe reductions in handball participation or performance, or to time-loss.ResultsThe weekly response rate was 86–96% and 83% of the players responded to at least 90% of the weekly reports. The previous season prevalence measured at baseline was 8% (95% CI 5–11%) among players in the 1st grade and 20% (95% CI (15–26%) in the 2nd and 3rd grades. During the prospective season, 22% (95% CI 17–27%) of players in the 1st grade reported having SSP, and 27% of players in the 2nd and 3rd grades. Of those with SSP at some point during the previous season, 67% (95% CI 54–77%) also reported SSP at least once during the prospective season.ConclusionsThe season prevalence of SSP is high among adolescent handball players and the prevalence increases when the players start high school. A majority of players with previous SSP also report subsequent SSP problems indicating that the pre-high school period is where prevention strategies preferably should be implemented.
LOWER LEG BIOMECHANICS ASYMMETRIES DURING LANDING AFTER ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION
Authors: Kimura Yuka , Yamamoto Yuji , Naraoka Takuya , Karita Yukiko , Tsuda Eiichi , Ishibashi Yasuyuki , Makino Misato 
Published: August 2017

BackgroundAsymmetries in knee motion have been identified as a risk factor for second anterior cruciate ligament (ACL)injury.ObjectiveTo investigate the kinematics and kinetics of knee joint and ground reaction force during landing after ACL reconstruction (ACLR).DesignControlled laboratory study.SettingThe patients after ACLR and being cleared to return to competitive sports.PatientsFour males and 8 females (23.2 years) at 43 (8–152) months postoperatively.Assessment of Risk FactorsThe subjects performed a drop vertical jump by dropping directly down off a box, and immediately performing a maximum vertical jump. The kinematic and kinetic data of the knee joint during landing were measured using 3-dimensional motion analysis system. The concentric peak torque of the quadriceps and hamstring muscle were measured using a dynamometer. KOOS were used to measure patient-reported outcomes.Main Outcome MeasurementsThe knee flexion and varus/valgus angle, maximum knee valgus moment and peek vertical ground reaction force (VGRF) during landing were measured.ResultsThe knee kinematics was not significantly difference between reconstructed and intact knees. Maximum knee valgus moment of reconstructed knees during landing was 0.2±0.1 Nm/kg/m, and that of intact knees was 0.4±0.2 Nm/k/m. Peek VGRF of reconstructed knees was 1.2±0.2 N/BW, and that of intact knees was 1.7±0.3 N/BW. There was significant difference in maximum knee valgus moment and peak VGRF between reconstructed and intact knees (p<0.05). Normalized muscle strength was above 80%. There were no significant correlations between knee valgus moment, VGRF, muscle strength and KOOS.ConclusionsSignificant asymmetry of knee valgus moment and VGRF has still been observed in ACL reconstructed patients who were satisfied to return to sports, and these were difficult to be predicted by muscle strength and subjective knee function. Assessments of biomechanical asymmetry may support a safer return to sports minimizing re-injury and contralateral injury rate for athletes.