Rationale: As every season, physical performance of players of Royal Antwerp FC's first team was regularly tested and mental well-being and mood were assessed during football season 2020–2021. Just like in the general population, several professional athletes were infected by SARS-CoV-2 during that season. COVID-19 is a complex disorder affecting multiple body systems, potentially damaging lungs, affecting the cardiovascular system or causing muscle weakness. Therefore, the impact of COVID-19 on performance was a major concern for the affected football players and their entourage.Objectives: To retrospectively examine the influence of COVID-19 on physical performance and mental health in professional football athletes during the season 2020–2021.Methods: Thirty-three professional athletes (age: 25.37 ± 4.11 years; height: 182.75 ± 7.62 cm; weight: 78.90 ± 8.97 kg) of a Belgian first division football club were assessed weekly during the 2020-2021 season. Weekly assessments comprised strength values of the hamstrings, hip abductors and hip adductors, jump performance, a modified Hooper questionnaire to assess mental status and nose swab PCR tests for COVID-19. Data analysis was performed from 2 weeks prior to COVID-19 contamination up to 8 weeks after the first positive test. Post-hoc Bonferroni correction was applied when performing statistical analysis.Results: Eleven players tested positive for COVID-19. Duration of contamination was 13 ± 7 days. There was no statistically significant difference before and after COVID-19 infection for jump performance, and adductor and abductor muscle strength (p > 0.05). Functional hamstring strength improved significantly 2 weeks (MD: 41.48; 95%CI: −3.79 to 86.75; p = 0.009) and 4 weeks (MD: 34.76; 95%CI: −8.91 to 78.42; p = 0.019) after COVID-19, whereas mood (MD: −0.60; 95%CI: −1.46 to 0.26; p = 0.041), stress levels (MD: −0.83; 95%CI: −1.85 to 0.20; p = 0.020) and total wellness (MD: −2.41; 95%CI: −5.25 to 0.43; p = 0.015) showed a significant reduction 8 weeks after confirmed COVID-19.Conclusion: Physical performance varied considerably across outcomes before and 8 weeks after COVID-19 contamination in a sample of first division football players. However, affected football players' overall well-being, stress levels and mood diminished after a positive COVID-19 test.

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Research questions 1) Do exercise-based rehabilitation programs reduce re-injury following acute ankle sprain?; 2) Is rehabilitation effectiveness moderated by the exercise’s therapeutic quality, content and volume? Methods This systematic review with meta-analysis (PROSPERO: CRD42020210858) included randomized controlled trials in which adults who sustained an acute ankle sprain received exercise-based rehabilitation as an intervention. Databases CINAHL, Web of Science, SPORTDiscus, Cochrane Central Register of Controlled Trials, PEDro and Google Scholar were searched for eligible articles (last search: March 2021). ROB II screening tool by Cochrane was used to assess risk of bias and the i-CONTENT tool was used to assess quality of interventions. Both qualitative analysis and quantitative data synthesis were performed. Results Fourteen randomized controlled trials comprising 2182 participants were included. Five studies were judged overall low risk of bias and i-CONTENT assessment showed poor to moderate therapeutic quality of exercise across all included articles. Pooled data found significant reductions in re-injury prevalence at 12 months, in favour of the exercise-based rehabilitation group vs usual care (OR: 0.60; 95%CI: 0.36 to 0.99). Pooled data for re-injury incidence showed not-significant results (MD: 0.027; 95%CI: -2.14 to 2.19). Meta-regression displayed no statistically significant association between training volume and odds of re-injury (r = -0.00086; SD: 0.00057; 95%CI: -0.00197 to 0.00025). Results from patient-reported outcomes and clinical outcomes were inconclusive at 1 month, 3–6 months and 7–12 months of follow up. Conclusion Exercise-based rehabilitation reduces the risk of recurrent ankle sprain compared to usual care, but there is insufficient data to determine the optimal content of exercise-based interventions. Training volume varied considerably across studies but did not affect the odds of sustaining a re-injury. Effects on patient-reported outcomes and clinical outcomes are equivocal. Future research should compare different exercise contents, training volumes and intensities after ankle sprain.

ObjectivesThis retrospective cohort study explored an algorithm-based approach using neuromuscular test results to indicate an increased risk for non-contact lower limb injuries in elite football players.MethodsNeuromuscular data (eccentric hamstring strength, isometric adduction and abduction strength and countermovement jump) of 77 professional male football players were assessed at the start of the season (baseline) and, respectively, at 4, 3, 2 and 1 weeks before the injury. We included 278 cases (92 injuries; 186 healthy) and applied a subgroup discovery algorithm.ResultsMore injuries occurred when between-limb abduction imbalance 3 weeks before injury neared or exceeded baseline values (threshold≥0.97), or adduction muscle strength of the right leg 1 week before injury remained the same or decreased compared with baseline values (threshold≤1.01). Moreover, in 50% of the cases, an injury occurred if abduction strength imbalance before the injury is over 97% of the baseline values and peak landing force in the left leg 4 weeks before the injury is lower than 124% compared with baseline.ConclusionsThis exploratory analysis provides a proof of concept demonstrating that a subgroup discovery algorithm using neuromuscular tests has potential use for injury prevention in football.

Study design Systematic review. Background and objective The International Ankle Consortium developed a core outcome set for the assessment of impairments in patients with lateral ankle sprain (LAS) without consideration of measurement properties (MP). Therefore, the aim of this study is to investigate MPs of assessments for the evaluation of individuals with a history of LAS. Methods This systematic review of measurement properties follows PRISMA and COSMIN guidelines. Databases Pubmed, CINAHL, Embase, Web of Science, Cochrane Library and SPORTDiscus were searched for eligible studies (last search: July 2022). Studies on MP of specific tests and patient-reported outcome measurements (PROMs) in patients with acute and history of LAS (>4 weeks post injury) were deemed eligible. Results Ten studies of acute LAS and 39 studies of history of LAS patients with a total of 3313 participants met the inclusion criteria. Anterior Drawer Test (ADT) in supine position five days post injury and Reverse Anterolateral Drawer Test are recommended in acute settings in single studies. In the history of LAS patients, Cumberland Ankle Instability Tool (CAIT) (4 studies) as a PROM, Multiple Hop (3 studies) and Star Excursion Balance Tests (SEBT) (3 studies) for dynamic postural balance testing showed good MPs. No studies investigated pain, physical activity level and gait. Only single studies reported on swelling, range of motion, strength, arthrokinematics, and static postural balance. Limited data existed on responsiveness of the tests in both subgroups. Conclusion There was good evidence to support the use of CAIT as PROM, Multiple Hop, and SEBT for dynamic postural balance testing. Insufficient evidence exists in relation to test responsiveness, especially in the acute situation. Future research should assess MPs of assessments of other impairments associated with LAS.

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IntroductionAnkle sprains are common in sports and the general population. Although considered innocuous, a large proportion has residual complaints such as recurrent ankle sprains and develop chronic ankle instability. Although some predicting factors are identified, there is no unequivocality regarding the development of chronic ankle instability, nor about the optimal rehabilitation for an acute ankle sprain. Alongside the biomechanical impairments, ankle sprains are a burden on society due to substantial economic costs. Therefore, we aim to identify key clinical predictors of chronic ankle instability or recovery after acute lateral ankle sprain. Additionally, we aim to determine cost-of-illness of patients who developed chronic ankle instability.Methods and analysisThis prospective cohort study (Clinicaltrials.gov:NCT05637008- pre-results) aims to recruit adult (18–55 years) patients with an acute lateral ankle sprain who are active in sports. Clinical assessments and patient-reported outcome measures will be used to collect data at 7–14 days, 6 weeks, 12 weeks and 12 months after enrolment in the study. The primary outcome will be chronic ankle instability at 12-month follow-up. Salient outcomes will be analysed by logistic regression to determine association with the development of chronic ankle instability. Participants will fill in a cost diary containing direct and indirect costs related to their injury.Ethics and disseminationsThe ethical committee of the Antwerp University Hospital (B3002022000138) has given approval of the protocol and consent forms on 10 October 2022. We perform this study according to the Helsinki Declaration. We will present results at conferences or webinars and publish in peer-reviewed articles.NCT05637008.

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