Exercise and the platelet activator calcium chloride both influence the growth factor content of platelet-rich plasma (PRP): overlooked biochemical factors that could influence PRP treatment

There is strong evidence that exercise affects platelet haemostasis factors, but this potential effect on growth factor concentrations in platelet-rich plasma (PRP) has never been studied. In addition, there is a paucity of studies focusing on the effects of activating agents used in conjunction with PRP. The first aim of this study was to evaluate the effect of exercise on platelet and platelet-derived growth factors (PDGF)-AB, hepatocyte growth factor (HGF), insulin-like growth factor-1 (IGF-1) and vascular endothelial growth factor (VEGF) concentrations in PRP. The second aim was to study the effect of the activating agent calcium chloride (CaCl2) on growth factor concentration in relation to different exercise states. Controlled laboratory study. Ten healthy participants performed 1 h of submaximal exercise with blood being withdrawn immediately pre, post and 18 h following. PRP was prepared in each condition in both an activated CaCl2 and non-activated form. Concentrations of PDGF-AB, HGF, IGF-1 and VEGF were evaluated using standard ELISA systems. Exercise had no significant effect on platelet concentration, but significantly suppressed both VEGF and PDGF-AB concentrations. Exercise state had no significant effect on IGF-1 or HGF concentration. Activation with CaCl2 resulted in a significant increase in PDGF-AB and IGF-1 concentrations, unchanged VEGF and significantly reduced HGF concentrations. Exercise significantly impacts on PDGFs in PRP with significantly reduced concentrations of VEGF and PDFG-AB. Furthermore, the activation of PRP with CaCl2 results in a differentiated GF release from platelets. These relevant factors can potentially influence outcome in daily clinical practice and are recommended to be accounted for in future study desig

Low injury rate strongly correlates with team success in Qatari professional football

Although the incidence of football injuries should relate to team success there is little empirical evidence. We investigated the relationship between injury incidence and team success in Qatar first-division football clubs. Using a prospective cohort study design, we captured exposure and injuries in Qatar male elite football for a season. Club performance was measured by total league points, ranking, goal scored, goals conceded and number of matches won, drawn or lost. Lower injury incidence was strongly correlated with team ranking position (r=0.929, p=0.003), more games won (r=0.883, p=0.008), more goals scored (r=0.893, p=0.007), greater goal difference (r=0.821, p=0.003) and total points (r=0.929, p=0.003). Lower incidence rate was strongly correlated with team success. Prevention of injuries may contribute to team succes

Concussion surveillance: do low concussion rates in the Qatar Professional Football League reflect a true difference or emphasize challenges in knowledge translation?

To investigate concussion epidemiology in the first football (soccer) division of Qatar. Prospective cohort study. Professional First Division Football League of Qatar. All first team players were included at the beginning of each season. Daily collection of training and match exposure from August 2008 until April 2012 by club medical staff. Head injuries during training and match play were recorded on standardized injury cards. Injury incidence was calculated as number of injuries per hour exposed to risk and expressed as rate per 1000 hours. The incidence of concussions in professional club football in Qatar is 0.016 (0.000-0.033) per 1000 hours of exposure. The concussion incidence is only 25% of that in the previous European studies using the same time loss injury definition. This raises the possibility that concussions are underreported. Further research is necessary. In the meantime, concussion education of players, club medical, and support staff is warranted, in keeping with the Zurich concussion consensus call for the need for an increase in knowledge translatio

Does Ramadan affect the risk of injury in professional football?

To investigate whether fasting during Ramadan influences injury incidence in professional Muslim and non-Muslim footballers. Prospective cohort study. Professional First Division League of Qatar. About 527 male football players (462 Muslim and 65 non-Muslim) from 7 league clubs (first year of data collection) and 8 clubs (second and third years). Daily collection of training and match exposure from August 2008 until April 2011 by club medical staff. Injuries during training and match play were recorded on standardized injury cards. Injury incidence was calculated as number of injuries per hour exposed to risk, and expressed as rate per 1000 hours. The probability of injury for different Arabic months between Muslims and non-Muslims was calculated using Generalized Estimating Equations (GEEs). There was no significant difference in total, match, and training injury incidence between the Ramadan and non-Ramadan periods. Non-Muslim footballers had a significantly higher injury incidence rate than Muslim footballers both during Ramadan (8.5 vs 4.0 injuries/1000 hours, P = 0.009) and non Ramadan (6.6 vs 4.9 injuries/1000 hours, P = 0.004) periods. The GEE analysis revealed that after adjusting for age and random factors (month and club), the probability of match injury among non-Muslims was the highest in Ramadan and the 2 consecutive following months (adjusted odds ratio of injury among non-Muslims compared with Muslims was 3.7 [95% confidence interval (CI), 1.7-7.9], P = 0.001 during Ramadan (ninth) month; 2.4 (95% CI, 1.1-4.9), P = 0.021 during 10th month; and 2.7 (95% CI, 1.2-5.8), P = 0.013 during 11th month). Finally, there was no change in injury patterns over the months of the Islamic calendar. Ramadan does not impact injury incidence for Muslim footballers in Qatar, suggesting the current adjustments and scheduling of football activities during Ramadan are sufficient. The increased match injury among non-Muslims during and 2 months post-Ramadan may suggest less effective coping strategie

Medical recommendations for home-confined footballers’ training during the COVID-19 pandemic: from evidence to practical application

In early 2020, the world is facing a global emergency called COVID-19. Many professional footballers around the world are home confined. The maintenance of physical capacity is a fundamental requirement for the athlete, so the training sessions must be adapted to this unique situation. Specific recommendations must be followed concerning the type of training, its intensity, the precautions that have to be followed to avoid the possibility of contagion, and the restrictions in accordance with the presence of any symptoms. This article analyses the available scientific evidence in order to recommend a practical approach

Platelet-rich plasma does not enhance return to play in hamstring injuries: a randomised controlled trial

To evaluate the efficacy of a single platelet-rich plasma (PRP) injection in reducing the return to sport duration in male athletes, following an acute hamstring injury. A randomised, three-arm (double-blind for the injection arms), parallel-group trial, in which 90 professional athletes with MRI positive hamstring injuries were randomised to injection with PRP-intervention, platelet-poor plasma (PPP-control) or no injection. All received an intensive standardised rehabilitation programme. The primary outcome measure was time to return to play, with secondary measures including reinjury rate after 2 and 6 months. The adjusted HR for the PRP group compared with the PPP group was 2.29 (95% CI 1.30 to 4.04) p=0.004; for the PRP group compared with the no injection group 1.48 (95% CI 0.869 to 2.520) p=0.15, and for the PPP group compared with the no injection group 1.57 (95% CI 0.88 to -2.80) p=0.13. The adjusted difference for time to return to sports between the PRP and PPP groups was -5.7 days (95% CI -10.1 to -1.4) p=0.01; between the PRP and no injection groups -2.9 days (95% CI -7.2 to 1.4) p=0.189 and between the PPP and no injection groups 2.8 days (95% CI -1.6 to 7.2) p=0.210. There was no significant difference for the secondary outcome measures. No adverse effects were reported. Our findings indicate that there is no benefit of a single PRP injection over intensive rehabilitation in athletes who have sustained acute, MRI positive hamstring injuries. Intensive physiotherapy led rehabilitation remains the primary means of ensuring an optimal return to sport following muscle injury. ClinicalTrials.gov Identifier: NCT0181256

Injury and illness epidemiology in professional Asian football: lower general incidence and burden but higher ACL and hamstring injury burden compared with Europe

Background: While football injury and illness epidemiology surveillance at professional club level in Europe is available, epidemiological data from other continents are lacking. Purpose: Investigating injury and illness epidemiology in professional Asian football. Study design: Descriptive prospective study. Methods: Professional teams from the Asian Football Confederation (AFC) league were followed prospectively for three consecutive AFC seasons (2017 through 2019, 13 teams per season, 322 team months). Time-loss injuries and illnesses in addition to individual match and training exposure were recorded using standardised digital tools in accordance with international consensus procedures. Results: In total, 232 665 hours of exposure (88.6% training and 11.4% matches) and 1159 injuries were recorded; 496 (42.8%) occurred during matches, 610 (52.6%) during training; 32 (2.8%) were reported as ‘not applicable’ and for 21 injuries (1.8%) information was missing. Injury incidence was significantly greater during match play (19.2±8.6 injuries per 1000 hours) than training (2.8±1.4, p<0.0001), resulting in a low overall incidence of 5.1±2.2. The injury burden for match injuries was greater than from training injuries (456±336 days per 1000 hours vs 54±34 days, p<0.0001). The two specific injuries causing the greatest burden were complete ACL ruptures (0.14 injuries (95% CI 0.9 to 0.19) and 29.8 days lost (29.1 to 30.5) per 1000 hours) and hamstring strains (0.86 injuries (0.74 to 0.99) and 17.5 days (17.0 to 18.1) lost per 1000 hours). Reinjuries constituted 9.9% of all injuries. Index injuries caused 22.6±40.8 days of absence compared with 25.1±39 for reinjuries (p=0.62). The 175 illnesses recorded resulted in 1.4±2.9 days of time loss per team per month. Conclusion: Professional Asian football is characterised by an overall injury incidence similar to that reported from Europe, but with a high rate of ACL ruptures and hamstring injury, warranting further investigations