There was an increased incidence of injury in hypermobile elite-level professional soccer players from an English Premier League club, resulting in more missed days from training and match play. These findings suggest a need for routine screening for hypermobility in professional soccer.

Football: a multi-site cohort study

ABSTRACTBackground: A recent study demonstrated joint hypermobility increased the incidence of injury in an elite football team utilising a univariate statistical model. Objectives:To compare injury incidence between hypermobile and non-hypermobile elite football players incorporating a multi-site design and multivariate inferential statistics.Methods: 80 players comprising 3 English Championship football teams were followed prospectively during the 2012-2013 season. Joint hypermobility was assessed according to the 9-point Beighton Criteria at the start of the study period. A cut-off score of ≥4 categorised a participant as hypermobile. Player exposure and time-loss injuries were recorded throughout.Results: Mean ± standard deviation incidence of injuries was 9.2 ± 10.8 injuries/1000h. The prevalence of hypermobility was 8.8%. Hypermobiles had a tendency for higher injury incidence (mean [95% confidence interval] difference, 5.2 [0.9-2.7] injuries/1000 h; p = 0.06). Cox regression analyses found training exposure to be highly significant in terms of injury risk (p < 0.001) for all participants. Non-hypermobiles had a lower injury risk (p = 0.11), according to the Cox model, which is suggestive but not conclusive that hypermobility predisposes injury risk.Conclusions: Hypermobility showed a trend towards increased risk of injury. Training exposure is a significant injury risk factor in elite football.

Maintaining muscle mass and function during rehabilitation from anterior cruciate ligament injury is complicated by the challenge of accurately prescribing daily energy intakes aligned to energy expenditure. Accordingly, we present a 38-week case study characterizing whole body and regional rates of muscle atrophy and hypertrophy (as inferred by assessments of fat-free mass from dual-energy X-ray absorptiometry) in a professional male soccer player from the English Premier League. In addition, in Week 6, we also quantified energy intake (via the remote food photographic method) and energy expenditure using the doubly labeled water method. Mean daily energy intake (CHO: 1.9–3.2, protein: 1.7–3.3, and fat: 1.4–2.7 g/kg) and energy expenditure were 2,765 ± 474 and 3,178 kcal/day, respectively. In accordance with an apparent energy deficit, total body mass decreased by 1.9 kg during Weeks 1–6 where fat-free mass loss in the injured and noninjured limb was 0.9 and 0.6 kg, respectively, yet, trunk fat-free mass increased by 0.7 kg. In Weeks 7–28, the athlete was advised to increase daily CHO intake (4–6 g/kg) to facilitate an increased daily energy intake. Throughout this period, total body mass increased by 3.6 kg (attributable to a 2.9 and 0.7 kg increase in fat free and fat mass, respectively). Our data suggest it may be advantageous to avoid excessive reductions in energy intake during the initial 6–8 weeks post anterior cruciate ligament surgery so as to limit muscle atrophy.

BackgroundOur recent systematic review showed that prospective studies found contradicting results concerning hamstring-quadriceps (H:Q) strength ratios as a risk factor for ACL injuries. All studies that express hamstring relative to quadriceps strength assume a proportional relationship yet this is not likely.Objectivei) To investigate if the H:Q strength relationship is proportional in athlete populations and ii) To evaluate the differences in participant rankings between the traditional way of calculating H:Q ratios and allometrically scaled H:Q ratios.DesignControlled laboratory study.SettingThe study was conducted both in a club and biomechanics laboratory setting.Participants71 male elite football athletes, 55 male recreational athletes and 48 female recreational athletes participated in the study.Assessment of Risk FactorsConcentric hamstring and quadriceps strength (Hcon and Qcon), and eccentric hamstring strength (Hecc) were tested in participants' dominant and non-dominant limbs using isokinetic dynamometry at an angular velocity of 60°/s.Main Outcome Measurementsi) Allometric exponents (AE) of the Hcon:Qcon and Hecc:Qcon relationships and ii) Chi-square relationships between population rankings based on the traditional H:Q ratios and the allometrically scaled H:Q ratios.Resultsi) Linear regression analyses showed that the Hcon:Qcon and Hecc:Qcon relationships were systematically non-proportional (AE ranged between 0.61 and 0.84) and ii) correcting H:Q ratios based on an average allometric exponent (0.65 for Hcon:Qcon and 0.78 for Hecc:Qcon) successfully removed bias from quadriceps strength, and significantly altered population rankings.ConclusionsQuadriceps strength meaningfully affects H:Q ratios, causing bias in proportionally scaled H:Q ratios. Unless if quadriceps strength itself is a risk factor, allometrically scaled H:Q ratios are a superior measure of H:Q strength (im)balance for injury risk analyses in athlete populations.