ACL injuries are common and represent a significant personal and societal burden. An ACL injury is a tear or sprain of the anterior cruciate ligament, one of the major ligaments in the knee. An estimated 70% of ACL injuries occur in non-contact sports. These tears most commonly occur during sports that involve sudden stops, changes in direction, jumping or landing. Female athletes have an increased incidence of ACL rupture, however, the causes of this pattern are still unknown. (4)  

Experimental studies show that hormonal, anatomic, environmental, and neuromuscular factors may put females particularly at risk for ACL injuries. (1) More specifically, estrogen levels, playing style, and neuromuscular control of the quadriceps and hamstrings affect the rate of ACL injuries. (2) Ligamentous laxity refers to the looseness of joints and has been said to predispose athletes to the injury of the joint, with high ligamentous laxity placing an individual at risk for an ACL injury. (3) Ligamentous laxity is influenced by the female sex hormones, estrogen and progesterone. (3) During the menstrual cycle, estrogen and progesterone levels fluctuate. (5) Experimental studies showed that at peak levels of estrogen, there is an increase in ACL laxity and a decrease in ACL strength. (4) However, the relative risk of ACL injury at any point in the menstrual cycle is still low. (4) Another possible factor that can account for the difference in rate of ACL injuries between males and females are anatomical differences. Women have wider pelvises and are more prone to pronation (which causes an increased thigh-foot angle) when compared to men. (4) It is believed that not one single factor can determine why females are more likely than males to experience ACL injury, but it is most likely due to a complex interplay between multiple factors.   

Prevention programs that include plyometrics, strength training, and improved jumping, stopping, and turning motions show promising results in decreasing the risk of an ACL injury. (2) Esurgi is currently developing a clinical screening tool to identify who is at risk for an ACL injury. This product, called the Joint Spy, is a knee sleeve that provides real time feedback for high speed sports. The sensor technology records and analyzes the magnitude, frequency, and variability of high-risk movement strategies in the field of play. This way, those at risk for ACL injuries can be identified for intervention and individuals can more effectively train and transfer safer movement strategies to the field of play through real-time feedback. ACL injuries are detrimental and take a long time to recover from. With the help of Esurgi’s Joint Spy, those at risk can more effectively train and transfer safer movement strategies to the field of play, return to sport quickly after injury, and decrease subsequent injuries. 

Works Cited

  1. Brophy, R., Silvers, H. J., Gonzales, T., & Mandelbaum, B. R. (2010). Gender influences: the role of leg dominance in ACL injury among soccer players. British journal of sports medicine, 44(10), 694-697.
  2. Boden, B. P., Griffin, L. Y., & Garrett Jr, W. E. (2000). Etiology and prevention of noncontact ACL injury. The Physician and sportsmedicine, 28(4), 53-60.
  3. Grana, W. A., & Moretz, J. A. (1978). Ligamentous laxity in secondary school athletes. Jama, 240(18), 1975-1976.
  4. Harmon, K. G., & Ireland, M. L. (2000). Gender differences in noncontact anterior cruciate ligament injuries. Clinics in sports medicine, 19(2), 287-302.
  5. Penton-Voak, I. S., Perrett, D. I., Castles, D. L., Kobayashi, T., Burt, D. M., Murray, L. K., & Minamisawa, R. (1999). Menstrual cycle alters face preference. Nature, 399(6738), 741-742.