A new study published in the October issue of the American Journal of Sports Medicine (AJSM) found screening the knee muscles of a noninjured female athlete with electromyography (EMG) technology can determine if she is at high risk for an anterior cruciate ligament (ACL) rupture.
"An ACL injury for a female athlete doesn't just affect them at the moment of injury; a high percentage of female athletes who suffer an ACL injury experience long-term consequences such as osteoarthritis and disability. This is unacceptable," says lead author, Mette K. Zebis, PhD, at the Institute of Sports Medicine Copenhagen and the Danish National Research Centre for the Working Environment. "Our research aimed to evaluate the possible use of EMG recording as a tool for ACL injury risk screening. If we can identify those at risk for the injury, we can help prevent it."
EMG analysis can be used to evaluate neuromuscular activity in specific muscles during sports specific movements. The study utilized the technology to screen 55 noninjured female athletes while they performed a standardized side-cutting maneuver. A side-cutting maneuver is used to "fake" the defensive player to one direction while the athlete moves in the opposite direction. The side-cutting maneuver was selected because this maneuver is highly common during a game, and a large number of non-contact ACL injuries appear to occur in this situation.
Of the 55 athletes studied, five had lower EMG signals in the medial hamstring muscle on the back of their thigh and higher activity in their quadriceps muscle. Those same five athletes experienced an ACL rupture later on in the competitive season.
Analysis was conducted on all subject's EMG signals and a high-risk zone was defined. Ten individuals initially fell into the high-risk zone, with five of those being the ones who subsequently experienced a non-contact ACL rupture.
The study is the first to define a specific muscle group activity that may predispose a female athlete to an ACL injury. The high-risk zone developed by Zebis and her coauthors is a "promising" tool, but she explains that further studies with a larger sample size are still needed to standardize neuromuscular screening for determining those in the high-risk zone.
"Our study provides a foundation," she says. "Larger studies should be conducted to confirm our suspicions that this screening tool will be a huge asset in preventing future female athletic injuries."
More information on the American Journal of Sports Medicine (AJSM), which is published by the American Orthopaedic Society for Sports Medicine (AOSSM), is at: www.ajsm.org.