Wednesday, January 13, 2010

ACL Injury Prevention – The Evidence Mounts

Unfortunately, knee injuries are all to commonplace in the sport of soccer. In particular girls suffer anterior cruciate injuries at a rate that is 4-8 times higher than their male counterparts. The reasons for this increased risk are somewhat debatable but most researchers suggest that deficiencies in strength, balance, agility and technique play key roles. Given this, several ACL injury prevention programs have been developed with the goal of correcting these deficits including the FIFA 11+ and the Santa Monica PEP programs, to name a few. A new study from researchers in Uppsala University in Sweden shows that a simple, low-cost warm-up program that incorporates components of awareness, technique and strength reduces the risk of knee injuries in female players by more than 75%.

Researchers enrolled 48 girl’s youth teams in two Swedish counties in the preventative training program (intervention group). Another 49 teams served as the control group. In all, more than 1500 players participated in the study. The players ranged in age from 12 to 19 years. The intervention program began with the start of pre-season training (February) and continued through the end of competition (October). The intervention group performed the HarmonKnee preventative program (LINK) twice per week during the pre-season and once per week during the regular season. This program has three key components, 1) to increase awareness about injury risks, 2) to provide a structured warm-up program and 3) to provide strengthening exercises designed to improve movement and reduce stress on the knee joint. The awareness component consisted of a player-directed seminar on the importance of preventing knee injuries. The training components were similar in nature to programs advocated by other groups such as the FIFA 11+. It consisted of 5 parts: 1) warm-up, 2) muscle activation, 3) balance, 4) strength and 5) core stability (LINK). The emphasis was placed on performing the exercises with good technique rather than on the number of repetitions. The exercises took 20-25 minutes to complete and required no extra equipment of resources.

Over the course of the study, the incidence, type and severity of knee injuries was recorded for each teams and each player. In addition, the number of practices missed due to recovery was noted.

The results are impressive. First, the researchers found that the compliance rate for the intervention was very high with nine of the 48 teams in the intervention group reporting 100% compliance and 36 other reported 75% compliance. Such high compliance rate suggests that coaches and players found the program to be easy to incorporate into the training sessions and enjoyable to perform.

Second, and most important, the intervention resulted in a 77% reduction in the knee injury incidence rate. For non-contact knee injuries, the rate was reduced by 90% and there were no ACL injuries in the intervention group. Also, the injuries that occurred in the intervention group were less severe than those that occurred in the control group.

This study adds to a growing body of research indicating that injury prevention programs can reduce the risk of ACL injury in female players. A review of multiple studies by Korean researchers shows that prevention programs are associated with a 60% reduction in knee injury incidence (LINK). A Norwegian study using the FIFA 11+ program showed a 46% reduction in knee injuries despite a relatively low compliance rate (LINK). As a bonus, the FIFA 11+ has been shown to improve both speed and power.

Based on this information, coaches should be strongly encouraged to include ACL injury prevention as part of their training sessions, especially coaches working with girls. The present study uses a program that is very simple and low-cost, one that requires as little as 20 minutes per session. Using the program as little as twice per week during the pre-season and once per week during the regular season is effective.

Many coaches feel that they already have a limited amount of time to work on the technical and tactical components of the game as well as including some fitness training. Ninety minutes a few times per week can be used up quickly. However, consider that most teams spend at least 10-20 minutes each session warming up. Using an injury prevention program as a warm-up would require only 5-10 additional minutes of practice time. Also, consider the considerable consequences of a single ACL injury. A conservative estimate of the surgical and rehabilitation costs of an ACL rupture is around $17,000. In addition, these patients are at a higher risk of developing osteoarthritis later in life. Add to that the emotional and psychological impact on the individual and the implications for team from losing a key player. When both the personal and financial costs of an ACL injury are weighed against the reduction in injury risk, it is easy to see how a few minutes per week spent on injury prevention is well worth the effort. This seems like a classic case of an ounce or prevention being worth much more than a pound of cure.

Reference:

Kiani A, Hellquist E, Ahlqvist K, Gedeborg R, Michaelsson K, Byberg L (2010) Prevention of soccer-related knee injuries in teenage girls. Archives of Internal Medicine, 170:43-49.