Muscle strength imbalances and poor flexibility are frequently described as risk factors for hamstring injury. Preventive strategies include eccentric exercises, but the influence of field eccentric exercises on these risk factors remains unclear. We investigated the influence of a field hamstring eccentric program on hamstring strength and flexibility. Twenty-seven amateur athletes were randomly assigned to an intervention (n=13) or control group (n=14). In the intervention group, participants were involved in 15 sessions of four eccentric exercises. Peak torque, hamstring-to-quadriceps ratios, passive and active flexibility were analyzed. No significant modifications of strength, passive or active flexibility were observed in the control group (p>0.05). Hamstring eccentric peak torque (+7.1%) and functional hamstring-to-quadriceps ratios (9.3%) were significantly increased (p<0.05) in the intervention group, but not concentric strength (p<0.05). Passive straight leg raise was significantly increased by 11.4° (+12.7%, p0.05). In conclusion, a 6-week eccentric program, including four field exercises for hamstring muscles, is an effective method of improving eccentric strength, functional ratios and, especially, passive flexibility. As this program may be easily implemented in a real-world context, this association of multiple eccentric exercises might be useful in an injury prevention strategy.

Isokinetic and functional jump tests are frequently performed for assessing the physical qualities of soccer players during preseason. The purpose of this investigation was to explore, in an elite soccer players population, the relationships between isokinetic strength and functional jump performances. Thirty-eight professional soccer players were evaluated as follows: isokinetic knee assessment in concentric (CON) mode (60, 240°/s) for quadriceps and hamstrings, and in eccentric (ECC) mode for the hamstrings only (30°/s); one-leg hop tests for distance (single hop (SH), triple hop (TH) and triple crossover hop (TCH)); one-leg vertical jump tests (countermovement jump, drop jump). Players with a low bodyweight normalised (BWN) quadriceps (Q) strength (3.14 Nm/kg; p < 0.05). Greater bilateral differences between uninjured and past injured lower limbs were found with isokinetics (Q CON 60°/s (mean bilateral difference (MBD): 10.3%; p < 0.01), Q CON 240°/s (MBD: 9.9%; p < 0.05), H ECC 30°/s (MBD: 16.1%; p < 0.001) than with functional tests (MBD: 2 to 9%; p > 0.05. In conclusion, due to their complementary role and implications for performance, functional and isokinetic tests should be associated in a preseason soccer players assessment.

COVID-19 vaccination raised concerns about its potential effects on physical performance. To assess the impact of COVID-19 vaccination on the perceived change in physical performance, we conducted an online survey among elite athletes from Belgium, Canada, France and Luxembourg, with questions about socio-demographics, COVID-19 vaccination, perceived impact on physical performance and perceived pressure to get vaccinated. Full vaccination was defined as two doses of mRNA or vector vaccine or a heterologous vaccine scheme. Among 1106 eligible athletes contacted, 306 athletes answered the survey and were included in this study. Of these, 72% perceived no change in their physical performance, 4% an improvement and 24% a negative impact following full COVID-19 vaccination. For 82% of the included athletes, the duration of the negative vaccine reactions was ≤3 days. After adjustment for potential confounding variables, practicing an individual sport, a duration of vaccine reactions longer than 3 days, a high level of vaccine reaction and the perceived pressure to get vaccinated were independently associated with a perceived negative impact on physical performance of more than 3 days after the vaccination. The perceived pressure to get vaccinated appears to be a parameter associated with the negative perceived change in the physical performance and deserves further consideration.

La recherche sur la thématique de la prévention lésionnelle a connu ces dernières années, et toujours actuellement, un développement important. Plusieurs modèles théoriques ont été décrits afin d’optimiser l’efficacité des stratégies préventives qui, si elles sont créées et pratiquées de manière rigoureuse, peuvent s’avérer particulièrement efficaces. Parmi ces modèles, nous pouvons notamment pointer les très récents « sports injury risk management approaches » qui pourraient s’avérer pertinents dans le futur mais qui doivent être confirmés par des études. Pour être efficace, une stratégie préventive devrait notamment inclure divers éléments tels que : un bilan médico-sportif de pré-saison, une action coordonnée sur plusieurs facteurs de risque, une compliance maximale des participants ainsi que du staff, et une quantification/gestion de la charge de travail. Research topic about sport injury prevention has importantly increased these last years. Several theoretical models have been developed with the aim of helping sport and medical staffs with preventive strategies, and many studies have demonstrated the high efficacy of preventive programs if quality conditions are met. Among these models, at least two “sports injury risk management approaches” have been recently described and their relevance needs to be confirmed by further research. In order to maximize efficacy, preventive strategies should include: pre-competition medical assessment, actions to decrease multiple risk factors at the same time, maximal compliance, training load quantification and monitoring.