Anterior cruciate ligament (ACL) injuries

Anterior cruciate ligament

After having had a brief mid-year break from writing I thought it was time to get back to the keyboard and write about an area that has interested me over the years; anterior cruciate ligament (ACL) Injuries, the reasons why they occur and how to prevent them.

Many sports medicine practitioners will attest that with the winter season comes ACL injury and the number of multidirectional sports played over this period is a key reason for this.

The ACL injury also remains one of the most common major sporting injuries requiring extensive rehabilitation and time away from sport.

For these reasons I thought it would be interesting to examine some of the causes of ACL injuries, who are the at risk players and are there any ways we can prevent ACL injuries from occurring.

Epidemiology and causes of ACL injury

ACL injury is generally seen in those sports that require a change of direction or ‘cutting’ action.

These sports include the football codes, along with basketball and handball in the Scandinavian countries.

The literature reports that females have a higher risk of ACL injury than males when exposed to similar sports (Moses, Orchard, & Orchard, 2012).

However there are generally a higher number of males that are reported having ACL injuries and this is likely due to the fact they play more of the higher risk sports.

Corresponding to this is that the various football codes tend to report higher rates of ACL injury compared to other sports.

Interestingly a study from Denmark showed a high proportion of ACL injuries occurring in young female athletes (Lind, Menhert, & Pedersen, 2009).

ACL injury prevention

Over the years there have been studies that have examined a variety of injury prevention programs.

Most of the time these studies show a reduction in injury rate if the programs are implemented.

This is especially true of the ACL prevention programs used in female handball players.

Whilst the program was being used ACL injury rates were reduced, however when the study concluded injury rates started to rise again (Myklebust, Skjølberg, & Bahr, 2013).

The researchers then looked at further promotion of the benefit of these injury prevention programs and found that over time there had been a general reduction in ACL injuries.

This tends to support the idea that if these ACL prevention programs are successfully implemented they can have an impact on the rates of injury.

What should an ACL injury prevention program involve?

In general there are three components that are included in most ACL prevention programs.

These are strength, neuromuscular and balance training.

There are some controversies to these elements, as some studies report no change to injury rates when adding balance training whilst others report a reduction with the use of static stretching (Taylor, Waxman, Richter, & Shultz, 2013).

The latter being a source of interesting discussion as recently static stretching has been shown to not reduce muscular injury. So the reality is we still don’t know exactly what should be included in an ACL prevention program.

Now what do I do?

It is common for research to leave us with some unanswered questions.

Most of the ACL injury prevention programs have common elements and all tend to show a reduction in injury rates.

With this in mind the recommendation is to stick with the common elements of the programs. These are:

• Lower limb strength training
• Neuromuscular or agility training – practice good body alignment with landing and changing direction
• Balance exercises – especially those that are specific to the sport being played.
• ACL injuries remain a major problem especially for those who compete in multidirectional sports. The cost of the injury can be substantial from a physical, psychological and financial perspective. It remains important that we find ways to reduce the incidence of injury. Research continues to show that if injury prevention programs are implemented then the number of ACL injuries can be reduced. The message remains enjoy your sport and why not add some of the recommendations above in your training program.

Feedback and discussion always welcome.

References

• Lind, M., Menhert, F., & Pedersen, A. B. (2009). The first results from the Danish ACL reconstruction registry: Epidemiologic and 2 year follow-up results from 5,818 knee ligament reconstructions. Knee Surgery, Sports Traumatology, Arthroscopy, 17(2), 117–124. doi:10.1007/s00167-008-0654-3
• Moses, B., Orchard, J., & Orchard, J. (2012). Systematic review: Annual incidence of ACL injury and surgery in various populations. Research in Sports Medicine, 20(3-4), 157–179. doi:10.1080/15438627.2012.680633
• Myklebust, G., Skjølberg, A., & Bahr, R. (2013). ACL injury incidence in female handball 10 years after the Norwegian ACL prevention study: important lessons learned. British Journal of Sports Medicine, (47), 476–479. doi:10.1136/bjsports-2012-091862
• Taylor, J. B., Waxman, J. P., Richter, S. J., & Shultz, S. J. (2013). Evaluation of the effectiveness of anterior cruciate ligament injury prevention programme training components: a systematic review and meta-analysis. British Journal of Sports Medicine, bjsports–2013–092358–. doi:10.1136/bjsports-2013-092358