Tell us more about yourself and the author team.
I am a postdoc researcher now at the University of applied sciences in Utrecht and at the National eHealth living lab, which is a part of the Department of Public Health and Primary care of Leiden University Medical Center, in the Netherlands. This study was part of my PhD trajectory (2016-2020) on hamstring injury prevention in male amateur football players, which was conducted at the University Medical Center in Utrecht, together with the Royal Netherlands Football Association.
In the past 10 years, I combined working as a physical therapist in primary care and in football, with teaching and research (PhD), after finishing my master’s in physical therapy science
The co-authors on this manuscript also collaborated on most other studies of my PhD. They are all great people to work with both on and off the field.
Michel Brink was my co-promotor. Michel is an assistant professor at the University Medical Center in Groningen at the department of human movement sciences. He has specialized in load and recovery monitoring in football.
Jur Brauers is currently doing his PhD at the University Medical Center Groningen. Where he and his colleagues are investigating resilience in football players. Jur also has a background in physical therapy and physical therapy science.
Maarten van Smeden is an associate professor at the Julius Center for health sciences and primary care at the University Medical Center Utrecht. Maarten is a statistician and epidemiologist and mainly focused on prediction modelling.
Vincent Gouttebarge is a professor in the section of Sports Medicine at the University of Pretoria, South Africa and an associate professor at the department of Orthopedic Surgery and Sports Medicine of the Amsterdam University Medical Centers. Vincent’s research focuses on health management in (professional) football players, both during and after their careers.
Frank Backx was my promotor and is a (now emeritus) professor in clinical sports medicine at the University Medical Center Utrecht. Frank has a long research track record on muscle and tendon injuries in football players, both from a clinical and a research perspective.
What is the story behind your study?
Hamstring injuries remain a major issue in professional and amateur football. Several studies have shown that the Nordic Hamstring Exercise program seems to be efficacious in preventing hamstring injuries, but adherence is low. Reasons for non-adherence are diverse, but it seems important that programs are functional and effective enough and need to enhance performance. We designed and executed a large cluster-randomized controlled trial in adult male amateur football players to investigate the efficacy of a bounding exercise program on hamstring injury prevention. We designed this bounding program to increase adherence by using functional, sport-specific exercises that are easy to implement and enhance performance through plyometric training. Despite these benefits, we did not find a preventive effect on hamstring injuries in amateur football players, and compliance decreased during the study period of one year.
In the past decade, a large body of literature has been created about effective injury prevention programs, as well as a body of knowledge about implementation strategies and perceptions of several stakeholders concerning injury prevention in football and other (team) sports. However, we know very little about players’ perceptions of specific intervention strategies and their reasons to adhere (or not) to these strategies. Therefore, we tried to gain more insight into the context of football players by investigating differences between characteristics of football players and by determining their perceptions of (adherence to) our preventive exercise program.
In your own words, what did you find?
We found weak but significant correlations between player characteristics and player perceptions of the bounding exercise program and adherence.
Although the relations are not strong, this can be an important finding that can guide practitioners (coaches and medical staff) when implementing effective preventive strategies.
The impact of an intervention in sports practice depends on the intervention’s efficacy, adherence to the intervention, and the execution of the exercises. When players don’t believe in the value of the intervention, it might result in not achieving the necessary intensity or lack of motivation and increasing frustration.
This lack of motivation and increasing frustration in one or two players might not be a problem, but social psychology tells us that group dynamics may be important and contribute to good adherence but can also decrease adherence drastically.
What was the main challenge you faced in your study?
The main challenge in this study was collecting data from all male adult football players after the season already ended. We did this by visiting the amateur football clubs during their summer break, after they played the playoffs, and tried to contact all teams and individuals to fill in the evaluation questionnaire. This was difficult since many teams had no practice sessions after the competition, and many players transferred to other teams.
If there is one take-home message from your study, what would that be?
The coaches and medical staff are, without a doubt, important stakeholders in injury prevention. The players, however, are the ones who need to execute the exercises. As all players have their own experiences (which serve as a basis on which they build) and know what works for themselves, we should include players’ characteristics and perceptions of injury prevention in designing and implementing these programs.
A one size fits all principle does not suffice. Therefore, it is important to consider individual characteristics and perceptions when designing or implementing injury prevention programs. For example, when designing an implementation strategy, it might help to first convince the older, more experienced players about the value of the program.
Adherence will probably increase when injury prevention programs are designed for individual players and target individual risk factors. Those targeted programs will likely remain a utopia for a while since we don’t know enough about individual risk factors and when exactly an inciting event results in an injury.
Nevertheless, we still need to improve injury prevention programs and the implementation of injury prevention. Therefore, research should focus on targeted prevention, and we all (coaches, medical staff, players and researchers) must think about improving the implementation of injury prevention in regular training sessions. One approach is to shift from injury prevention towards a combination of injury prevention and performance enhancement. This approach has to result in attractive football-specific exercises. When players do realize they can prevent spending time on rehabilitation from hamstring injuries and can use all their time on increasing fitness and performance, there is a win for everyone.