British Journal of Sports Medicine

Verschueren, Jo; Tassignon, Bruno; Pauw, Kevin De; Proost, Matthias; Teugels, Amber; Cutsem, Jeroen Van; Roelands, Bart; Verhagen, Evert; Meeusen, Romain

doi: 10.1136/bjsports-2020-IOCAbstracts.40pmid: N/A

BackgroundAcute fatigue is hypothesized to alter injury risk profiles by affecting intrinsic risk factors (i.e. postural control, hamstring strength). However, no systematic overview exists that merges the insights of prospective lower extremity injury risk profiling with the effect of acute fatigue on functional test performance.ObjectiveThe objective of this review was to identify the influence of acute fatigue on prospectively determined modifiable intrinsic risk factors for lower extremity injuries and to determine if individual fatigue outcomes should be integrated within an athlete centred injury risk profile and prevention strategies.DesignSystematic review.MethodsPubMed (MEDLINE), Web of Science, PEDro, and Cochrane Library were searched until 29 May 2019. Studies were eligible when the study outcomes encompassed intrinsic modifiable risk factors, an acute fatigue intervention, and included healthy athletes or physically active people. Intrinsic modifiable risk factors were identified through recent systematic reviews and meta-analyses. Referenced original research papers were used to determine outcome measures associated with increased injury risk.Main outcome measurementsAcute fatigue effect on the intrinsic modifiable risk factors for lower extremity injuries.ResultsForty studies reported acute fatigue effects on modifiable risk factors, with eight studies matching all criteria for data-extraction. Acute fatigue can decrease single leg postural control, decrease ankle joint position sense, decrease isokinetic strength of hamstring and quadriceps muscles and can affect isokinetic H:Q ratios.ConclusionsAcute fatigue affects prospective intrinsic modifiable risk factors, indicating an altered injury risk profile for lateral ankle sprain, patellofemoral pain syndrome and hamstring injuries when fatigued. Current data does not allow conclusions for non-contact ACL injury risk. Clinicians should consider acute fatigue responses as part of injury risk profiling strategies. Future research should allow for individual fatigability as a relevant injury risk outcome and merge insights from athlete centred injury risk profiling and fatigue research.

Beidler, Erica; Alghwiri, Alia; Wallace, Jessica; O’Connor, Siobhán

doi: 10.1136/bjsports-2020-IOCAbstracts.323pmid: N/A

BackgroundConcussion is a global sports injury. Concussion awareness, understanding, and reporting behaviors (C-AUB) may vary by geographical location and be influenced by a number of factors (e.g., media publicity, access to healthcare providers, sport values, societal culture). Previous research has not compared C-AUB across countries.ObjectiveTo determine if there are difference in collegiate athletes’ C-AUB between countries with varying degrees of concussion publicity [USA (high), Ireland (moderate), Jordan (low)].DesignCross-sectional.SettingCollegiate athletics.ParticipantsCollegiate athletes from the USA (n=964), Ireland (n=302), and Jordan (n=129) who participated in an institution-sanctioned sport.InterventionsA single-time, 10–15 minute survey.Main outcome measurementsOutcome measures were concussion education (awareness; 21 options; select all sources that concussion information had been acquired from), concussion knowledge (understanding; max score of 49; assessment used in previous literature), and diagnosed/non-disclosed concussion history (reporting behaviors; self-report yes/no items).ResultsA far higher proportion of Jordanian athletes report never having received concussion information from any source (73.6%), than Irish (24.2%) or USA athletes (9.4%). Concussion knowledge differed between countries (p<0.0001, η2=0.28), with USA athletes displaying significantly higher total knowledge scores (40.9±4.5) and symptom scores (27.3±3.9) than Jordanian (35.1±5.6, 25.2±3.4) and Irish (32.1±3.5, 20.1±2.5) athletes. A greater percentage of Irish and USA athletes reported history of a diagnosed concussion (31.8%, 29.6%) and history of concussion non-disclosure (25.2%, 15.5%), than Jordanian athletes (2.3%, 0.0%).ConclusionsConcussion awareness may not reach all athletes to the same degree globally. In the USA, where concussion publicity is high, formal legislation exists, and there is increased access to sports medicine resources, a greater level of awareness and understanding was noted. More concussion awareness from a global perspective is needed to ensure collegiate athletes can identify when a concussive injury has occurred and understand the dangers associated with continued sport participation while concussed.

Mok, Kam Ming; Lau, Ivan YH; Louie, Lobo; Shu Hang Yung, Patrick

doi: 10.1136/bjsports-2020-IOCAbstracts.127pmid: N/A

BackgroundIncidence rate of knee injury in mixed martial arts (MMA) is high. MMA is a high-intensity sport that requires constant angle and level change. A majority of the combined movements overlap with biomechanics that have been suggested to be associated with increased risk of knee injury.ObjectiveTo identify the frequency of occurrence of the high-risk movements, i.e. dynamic valgus, during MMA competitions.DesignVideo-based notation analysisSettingThe analysed movements have been separated into two categories, Gross Biomechanical Risks and Detailed Biomechanical Risks. High-intensity movements were analysed in slow motion to ensure accuracy. Three fights were re-watched after all 29 fights as quality control to access the reliability of measurement.Patients (or Participants)29 MMA fights.Interventions (or assessment of risk factors)Documenting all visible high-risk knee injury movements occurred in the fights.Main outcome measurementsThe frequency of occurrence of the high-risk movements, i.e. dynamic valgus, during MMA competitions. In addition, other gross biomechanics were recorded.ResultsOn average, a MMA athlete experienced 31 times of knee valgus motion with explosive force drag during a match. The side affected was highly subjective to the stance of the fighter. The rear leg was most likely to go through knee valgus motion.ConclusionsThe result showed high-risk knee motions are common in MMA. Based on the data, knee valgus on the rear leg is of interest for future injury prevention focus. The data collected in this study can be used as the backbone for further investigation on the possible ways in knee injury prevention.

Morikawa, Masanori; Urabe, Yukio; Sasadai, Junpei; Kotoshiba, Somu; Komiya, Makoto; Fukui, Kazuki; Maeda, Noriaki

doi: 10.1136/bjsports-2020-IOCAbstracts.112pmid: N/A

BackgroundRecent researches showed that vibration stimulus around shoulders temporally increased muscle activity and strength of shoulders at almost same vibration frequencies (30Hz or 35Hz). However, there was no study to investigate whether vibration stimulus around shoulders improves the sensorimotor control, which can be assessed with static and dynamic stability test, at different vibration frequency.ObjectiveTo investigate the effect of vibration stimulus on the sensorimotor control around shoulders and the effective frequency of vibration stimulus.DesignCase-crossover study.SettingResearch laboratory.Patients (or Participants)Ten healthy collegiate men without orthopedic disease.Interventions (or assessment of risk factors)Participants placed both hands on a vibration platform with partial weight bearing in push-up position during a vibration protocol. Vibration protocol included 6 sets and rest for 30 seconds at 0Hz (control), 30Hz, and 50Hz frequencies.Main outcome measurements1) The center of pressure (COP) velocity during 30 seconds in the push-up position with their hands on the force platform as static stability test and 2) Upper Quarter Y Balance Test (UQYBT) composite score as dynamic stability test were collected before and after intervention.ResultsFor COP velocity, two-way repeated measures ANOVA showed a significant main effect for the time (pre vs post) (p<0.05). Paired t-test as post hoc analysis showed COP velocity was significantly faster from pre to post only at 0Hz (9.74±0.97 mm/s vs 10.12±0.98 mm/s, p<0.05), meant to become instable. In the UQYBT, there were significant main and interaction effects for the time and vibration frequency (p<0.05). Bonferroni test showed the amount of change for composite scores were significantly greater in 30Hz (5.28±3.53% vs -1.00±3.36%, p<0.01) and 50Hz (4.27±3.68% vs -1.00±3.36%, p<0.05) than 0Hz and not significant between 30Hz and 50Hz.ConclusionsThe vibration stimulus maintained static stability and improved dynamic stability test for the shoulder. There was no effect in these tests between vibration frequencies.

Rambaud, Alexandre; Neri, Thomas; Morin, Jean-Benoit; Philippot, Remi; Rossi, Jeremy; Samozino, Pierre; Edouard, Pascal

doi: 10.1136/bjsports-2020-IOCAbstracts.221pmid: N/A

BackgroundA test battery is recommended after anterior cruciate ligament reconstruction (ACLR) to help decision-making of return to sport (RTS). Running is important in RTS continuum, but it is currently not included in the usual test batteries. Could running pattern asymmetry, which can be observed after ACLR, be considered as a risk factor of ACL re-injuries?ObjectiveTo analyse the interest of adding running pattern evaluation in test battery after ACLR.DesignProspective cohort study. Setting Patient with ACLR with Tegner score >6 and Marx Scale score >8 before first ACL injury.Patients (or Participants)21 patients (12 women) with primary ACLR (graft type: Patellar (n=4) or Hamstring tendon (n=17)) without major chondral and/or meniscal lesion.Interventions (or assessment of risk factors)Running pattern evaluation was performed on a motorised instrumented treadmill in addition to recommended tests (questionnaires, knee laxity, Hop Tests and isokinetic evaluation) at 6 months after ACLR. ACL re-injuries were prospectively collected during the two years after ACLR, and comparisons between parameters were performed between ACLR patients who presented or not an ACL re-injuryMain outcome measurementsLimb symmetry Index (LSI=operated leg/healthy leg x100) were calculated for running variables (Stride Length, Loading Rate, Leg Stiffness) and other parameters of test battery. Means were compared between groups.ResultsFive patients had a re-injury (3 W/ 2 M), without significant differences in baseline characteristics (sport level, training frequency) with un-re-injured patients. For running variables, there was a significant difference for LSIs of Stride Length (Re-injury group 95.8±2.3% vs 99.0%±1.8%, p=0.003), Loading Rate (86.9±13.3% vs 98.3±9.6%, p=0.025), and Leg Stiffness (112.6±7.3% vs 103.7±8.0%, p=0.035), while there were no statistical differences for LSIs of other parameters of test battery.ConclusionsAs greater running pattern asymmetry was reported in patients with ACL re-injury, this approach could be of interest for secondary prevention.

Gallagher, Julie; Ashley, Paul; Needleman, Ian

doi: 10.1136/bjsports-2020-IOCAbstracts.350pmid: N/A

BackgroundPoor oral health of elite athletes is associated with negative performance impacts. There is a need for oral health promotion and prevention strategies that are effective within the elite sport environmentObjectiveTo develop, implement and evaluate a pragmatic oral health promotion intervention based on contemporary behaviour change theory and informed by input from all stakeholders in elite sport.DesignInterrupted time-series intervention study.SettingThree separate UK elite athlete-training centres.Patients (or Participants)62 athletes from two Olympic and one professional athlete training squads; 55 athletes completed the study.Interventions (or assessment of risk factors)Two levels: Level 1. Athletes and support team viewed combined one 10-minute presentation focussed on building motivation and three 90-second information films. Level 2. Athletes alone received oral health screening, personalised advice and an oral health toolkit focussed on opportunity and capability. Follow-up of athletes at one and three months.Main outcome measurementsImpact on performance (OSTRC questionnaire), oral health knowledge (8-item questionnaire), gingival inflammation, self-reported oral health problems and oral hygiene routines.ResultsAt baseline, 41 (66.1%) athletes had evidence of caries, 29 (46.8%) evidence of erosion, mean bleeding score was 11.57 (8.11), 44 (71%) were male and 58 (93.5%) white British. Mean OSTRC score reduced from 8.73 (14.54) to 2.73 (11.31) p<0.001. Mean knowledge score improved from 5.69 (1.59) to 6.93 (1.32) p<0.001. Gingival bleeding score was unchanged. Self-reported oral health problems reduced. Athlete use of prescription fluoride toothpaste (2800 ppm) increased from 8 (12.9%) to 45 (80.4%, p<0.001).ConclusionsThis behaviour change theory-based intervention was implemented within different elite sport environments. It was associated with a reduction in self-reported performance impacts, an increase in athlete oral health knowledge and enhanced oral health behaviour.

Ma, Shen-Ying Richard; Victoria, Christian; Ompad, Danielle C; Weinstein, Meryle G; Cantu, Robert C; Genece, Jordan; Allen, Answorth A; Lopez, Victor

doi: 10.1136/bjsports-2020-IOCAbstracts.254pmid: N/A

BackgroundHead and neck injuries are a collision sport concern, however there is a lack of Rugby-7s injury data, particularly in emerging Rugby nations.ObjectiveTo determine the head, neck, and face (HNF) match injury rates and characteristics in US Rugby-7s.DesignProspective descriptive epidemiology study.SettingUSA Rugby-sanctioned tournaments/series and championships (2010–2016).Participants42,054 adult U.S. players (3,481 teams and 7,673 Rugby-7s matches).Assessment of risk factorsMatch injury rates, site, type, and severity.Main measurement outcomeIncidence (per 1000 player-hour (ph)), severity and details of mechanisms were captured using Rugby Injury Survey & Evaluation (RISE) report methodology. All-injuries (medical-attention and time-loss) and time-loss injuries were defined. Days (d) absent before return-to-training/competition (including post-tournament) were recorded.ResultsA total of 498 HNF injuries were encountered (all-injury rate=16.7/1000ph; men=17.3/1000ph; women=15.5/1000ph; IRR:1.1; CI:0.9–1.4). Head/face was the most commonly injured site (all-injuries=90.8%; time-loss=86.8%) followed by neck/cervical spine (all-injuries=9.2%; time-loss=13.2%). Concussions were the most common type of injury (36.7%; 6.1/1000ph) followed by facial lacerations (28.7%; 4.8/1000ph). Incidence of concussions was similar between sexes (IRR:1.0; CI:0.7–1.3). Longer return-to-sport were seen among women (46.4d) than men (32.1d; P=0.047) post-concussion. Scalp/face lacerations were more common among men than women (IRR:2.5; CI:1.6–4.1; P<0.001). Time-loss injuries occurred similarly among men and women (IRR:1.5; CI:1.0–2.6; P=0.061). HNF injury severity was similar between sexes (29.3±32.4 days absent from play). The tackle (71.5%) was the most common injury event. Men sustained HNF injuries mostly with direct contact with another player (IRR:1.3; CI:1.0–1.7; P=0.023), while women were injured with impact with the playing surface (IRR:1.8; CI:1.0–3.2; P=0.032).ConclusionsIncidence of HNF injuries were similar between sexes among U.S. rugby-7s players. Sex differences with concussion severity and contact mechanism of HNF injuries were seen between sexes. Recognition of HNF injury patterns and sex differences will allow for a more effective injury prevention plan in this emerging U.S. collision sport.

Peek, Kerry; Ford, Kevin; Myer, Gregory; Hewett, Timothy; Pappas, Evangelos

doi: 10.1136/bjsports-2020-IOCAbstracts.321pmid: N/A

BackgroundKnee extensor and flexor strength are associated with injury risk, including rupture of the anterior cruciate ligament. However, the longitudinal changes in lower extremity strength with maturation have been under-investigated.ObjectiveTo investigate the longitudinal changes of knee extension and flexion strength associated with maturationDesignThe pubertal status [pre-pubertal, pubertal, and post-pubertal] was determined with the modified Pubertal Maturation Observation Scale questionnaire. After a warm-up of five submaximal repetitions, participants were tested for concentric peak isokinetic strength for knee extension and flexion at 300°/s.SettingLaboratory.Patients (or Participants)Males and females participating in high school sports who were measured longitudinally in at least two different pubertal stages (N=257, 208 females, 18 excluded due to knee injury).Interventions (or assessment of risk factors)N/AMain outcome measurementsPeak knee extension and flexion isokinetic torque was measured across 10 repetitions and normalized to body weight. Separate linear mixed models were used for the right and left side to test for the effect of pubertal stage, sex and their interaction.ResultsSignificant interactions were identified indicating a different maturational effect on knee muscle strength for males and females, particularly between pre-pubertal and pubertal stages where males demonstrated higher knee extension increases than females (+12% vs. +5% on right, +11% vs. +7% on left, p<0.001) while for knee flexion males demonstrated increased while females demonstrated decreased flexor strength (+4% vs. -1% on right, p=0.03 and +3 vs. -3% on left, p=0.009).ConclusionsThe findings of this study support a differential effect of maturation on important knee strength outcomes that may have implications for the higher rates of knee injury in females as they mature. Interventions to strengthen the knee flexors should target females at the beginning of puberty and emphasized in injury reduction programs aimed at young athletes of both sexes.

Leppänen, Mari; Rantala, Anni; Parkkari, Jari; Vasankari, Tommi; Äyrämö, Sami; Krosshaug, Tron; Kannus, Pekka; Heinonen, Ari; Pasanen, Kati

doi: 10.1136/bjsports-2020-IOCAbstracts.54pmid: N/A

BackgroundStudies investigating biomechanical risk factors for knee injuries in sport specific tasks are needed.ObjectiveTo investigate association between cutting technique and knee injury risk among youth team sports.DesignProspective cohort study.SettingYouth basketball and floorball.Participants396 players (aged 12–21).Assessment of risk factorsTwo cutting tasks were analysed using 3D-motion analysis: 90-degree cut (Cut90) and 180-degree pivot turn (Pivot180). Basketball players performed only Pivot180-test. The pivot tests included a quick pass before and after a 180-degree turn on the force plates.Following variables were analysedPeak vertical ground reaction force (vGRF,N/kg), peak knee flexion angle (degree), knee flexion angle at initial contact (IC) (degree), peak knee abduction moment (Nm/kg), peak knee valgus angle (degree), and knee valgus angle at IC (degree). Mean of three trials was used. Injuries and exposure were registered for 1–3 years.Main outcome measurementsNew acute non-contact knee injury.ResultsData was obtained from 337 players (164 female, 173 male). 35 non-contact knee injuries were registered (0.3 injuries/1000h of exposure). Female players had higher rate of knee injuries compared with male (incidence rate ratio 3.7, 95% CI 1.7–8.8).Females displayed significantly larger peak knee valgus (mean for female and male: 11.3 and -0.6 degree in Cut90; 13.9 and 2.3 degree in Pivot180) and IC knee valgus angles (5.4 and -5.3 degree in Cut90; 8.5 and -2.0 degree in Pivot180) in both tasks compared with males. Larger knee abduction moment (1.6 and 1.4 Nm/kg) and vGRF (21.1 and 20.2 N/kg) was observed in females in Cut90.In unadjusted regression models, peak knee valgus angle (HR 1.04, 95% CI 1.00­–1.09) and valgus angle at IC (HR 1.06, 95% CI 1.02­–1.12) during the Cut90 were associated with knee injury risk. No significant associations were found in adjusted analyses.ConclusionsFemale players performed cutting tasks with significantly larger knee valgus compared with male. However, knee valgus loading during cutting was not associated with knee injury risk in youth basketball and floorball players.

Ballet, Charles

doi: 10.1136/bjsports-2020-IOCAbstracts.311pmid: N/A

BackgroundProfessional football players seek less professional support regarding their mental wellbeing compared to the general population. Video media is proving a popular and effective modality to engage and educate athletes.There are no published studies that have investigated interventions designed to encourage help-seeking behaviour in Professional Football.ObjectiveThis study investigated the efficacy of a video intervention on its potential to increase intentions and attitudes towards mental health help-seeking.DesignParticipants completed a validated pre and post-test questionnaire on help-seeking attitudes and intentions. A six-minute video of an ex-professional footballer telling of his mental health struggles and seeking help was watched on mobile phone.SettingPlayers were approached from three English professional football clubs and 25 players agreed to participate.Main outcome measurementsWe investigated help-seeking attitudes and intentions.ResultsThe intervention did not produce a significant change in help-seeking intentions and attitudes. However, there was a trend to increase in help-seeking attitudes (Z=-1.130, p=0.26) and to reduce in help-seeking intentions (Z=-2.195, p=0.03) at postintervention.ConclusionsA short video of an ex-player telling of his experience with mental health issues and help-seeking does not appear to promote a significant positive change in help-seeking attitudes and intentions in the event of mental health struggles of professional football players. Nevertheless, given the trend in our findings, further studies of using video media to improve help seeking should be encouraged with greater numbers and including females.