What do the new guidelines on knee injury prevention for athletes tell us?

Earlier this year, the Academy of Orthopaedic Physical Therapy and the American Academy of Sports Physical Therapy updated their Clinical Practice Guidelines (CPGs) on Exercise-Based Knee and Anterior Cruciate Ligament Injury Prevention. The last attempt to review the evidence and provide guidance on the best practices for exercise-based knee injury prevention was back in 2018 and these updated guidelines have been eagerly awaited. 

The guidelines are written in line with the International Classification of Functioning, Disability and Health (ICF) framework of musculoskeletal impairments – an approach that emphasises on the positive abilities of an individual and their active role rather than focusing on the negative undertones of diseases.

Why knee injury prevention is so relevant

Musculoskeletal injuries are common in athletes of all levels (as well as in the general population), and the nature of these injuries varies between sports. Knee injuries refer to a range of knee conditions, which involve different mechanisms of pathology. Anterior cruciate ligament (ACL) injuries specifically occur particularly in sports involving pivoting, such as football, basketball, netball, handball and downhill skiing. Whilst there is a significant burden of sport-related musculoskeletal injuries, this is far outweighed by the benefits of participation in sport in terms of public health across the lifespan – so mitigating injury risk is paramount.

Injury prevention programmes are therefore an important part of athletic training programmes – with the aim of reducing injury, and re-injury, as much as possible. Exercise-based prevention is defined as an intervention requiring the participant(s) to be active and move, which may include physical activity, strengthening, stretching, neuromuscular, proprioceptive, agility and plyometric exercises. 

What’s new in the updated guidelines

The updated guidelines discuss new evidence and provide up-to-date recommendations on orthopaedic and sports physical therapy management and prevention as follows:

Exercise-based knee injury prevention programmes are recommended both in general and for specific subgroups of athletes

  • Further evidence has been found to support the use of exercise-based knee and ACL injury prevention
  • Strong evidence for benefits (i.e., reduction in risk for all knee injuries and for ACL injuries specifically, little risk of adverse events and minimal cost) of exercise-based knee injury prevention programmes has been found
  • A randomised controlled trial (RCT) provided new evidence potentially suggesting benefit of exercise-based knee injury prevention in secondary ACL injury prevention. Further research is required regarding secondary prevention using exercise-based programmes
  • Greater diversity in the athlete populations studied is needed since the majority of included studies currently come from the western world and report minimal data sample characteristics beyond age and sex. Communities currently underrepresented in the literature, as well as those underserved or overlooked by current health care systems, should be considered in future research.

Details around components, dosage and delivery of exercise-based knee injury prevention programmes are still unclear

  • Very little new acceptable evidence has been found in the area of components, dosage and delivery, as well as compliance. Only one level II study, supporting the use of proximal control/hip strengthening components within exercise-based knee and ACL injury prevention programmes was added
  • More research is still needed on the dose–response relationship of exercise-based knee and ACL injury prevention programmes, and around improving compliance and adherence.

There is scarce new evidence on implementation of exercise-based knee injury prevention programmes

  • The new evidence continues to support the 2018 recommendations that there is no increase in risk of adverse events when all athletes perform prevention programmes instead of applying to high-risk athletes only, and there is no harm in performing prevention programmes
  • Increase in cost due to the higher number of athletes participating in such programmes is likely outweighed by the reduction in ACL injuries and long-term healthcare costs. In addition, most exercise-based knee and ACL injury prevention programmes are designed as dynamic warm-ups prior to training sessions or games
  • Alternative implementation models, such as executing strengthening portions at the end of training sessions and models that look beyond the physical aspects of injury prevention may also need to be considered in future research.

Taking into account the newly available evidence, the recommended injury prevention algorithm from the previous 2018 guidelines is further supported by the new guidelines.

On the Physiopedia Knee Injury Prevention page you can read about the updated evidence on exercise-based prevention programmes and specifics of the algorithm for exercise planning.