Anterior Cruciate Ligament (ACL)

Anterior cruciate ligament (ACL) injuries represent a highly relevant issue in both grassroots and professional sports, with a particularly high incidence in young and female populations. The objective of this project is to develop and validate a multiscale predictive algorithm for ACL injury risk in athletes from Villarreal CF (aged 10-45), integrating biomechanical, physiological, genetic, and gut microbiome biomarkers. The study, with a prospective and longitudinal design (4 years), will include a cohort of 200-250 players from the academy and first team. The following assessments will be conducted: biomechanical analysis of jumps using force platforms (instrumented LESS), physiological monitoring through resting heart rate and nocturnal heart rate variability (HRV), genotyping from saliva samples, and characterization of the gut microbiome 16 rRNA sequencing. The systematic recording of training, exposures, and injuries will follow OSTRC criteria and will be supervised by the club's medical team. The expected outcome is a multivariate predictive model, validated in a professional sports setting, capable of identifying individual risk profiles and generating a personalized score to guide preventive interventions (exercise, strength training, nutritional or probiotic strategies). This approach aims to reduce the incidence of ACL injuries, optimize performance, and translate biomedical knowledge into clinical and sports practice.

Muscle qualities are critical for the recovery after an anterior cruciate ligament (ACL) injury. Before ACL reconstruction (ALCR), resistance training aims to maintain patient strength and volume in order to optimize recovery. Unanswered questions remain on the modalities of resistance training before ACLR. This protocol details a pragmatic clinical trial that primary aims to increase the maximal strength of knee extensors and flexors and to induce hypertrophy before ACLR. Participants awaiting ACLR will be recruited from outpatient rehabilitation clinics and will be randomly allocated to one group to attend a 9-weeks rehabilitation program before ACLR. Participants of 'resistance training' group will perform a training program built on the principles of strength training to increase knee muscles strength and volume. Three blocks of 3 weeks will induce a progressive increase in training load, with exercises performed close to failure. Participants of 'usual group' will perform traditional exercises including: balance/proprioceptive exercises, weight-balances exercises, and body-weight resistance training exercises. Groups will be compared on muscle strength (primary outcome), clinical outcomes (muscle volume, stiffness, knee mobility, effusion) and self-reported outcomes (quality of life, perception of knee function, pain, anxiety and depression, exertion, health consumption, participations in activities) before and after ACLR. Outcomes will be collected by a blinded assessor before and after the resistance training program (before ACLR); 4 and 9 months after the ACLR.