School has started and so have fall sports. As we return to the training and playing fields, it’s important to remember to try to keep sports activities safe and prevent injury.
By Louis F. McIntyre, M.D.
School has started and so have fall sports. As we return to the training and playing fields, it’s important to remember to try to keep sports activities safe and prevent injury.
The hallmarks of safe sports are fitness, proper technique, good equipment, and field conditions. Even when all these aspects of sports are optimized, injury can occur. Knee injuries can be especially damaging for young female athlete. As these injuries can end a season and threaten a career, it is important to understand how these injuries occur and take steps that can decrease injury incidence.
The anterior cruciate ligament (ACL) is the ligament that prevents the shin bone from moving forward on the thigh bone and also controls anterolateral shifting of the joint. When you plant your knee and move in the opposite direction, it is your ACL that stabilizes the joint. The ACL is the ligament that is commonly injured in collisions in football, rugby and other contact sports. In the last few years, ACL injuries have been seemingly epidemic in women’s soccer, basketball and other sports and mostly without a collision. The injuries occur with planting and twisting of the joint.
When a player injures an ACL she may feel a “pop” and have immediate swelling. There is usually pain but sometimes the injuries are pain-free. The joint will become stiff and feel like it will “give way” and not support weight. Players can sometimes continue to run straight ahead but cutting, pivoting and jumping are difficult or impossible. When and if such an injury occurs the athlete should be removed from play and seek immediate medical attention along with ice and elevation of the joint.
Injury rates for men and women are known to be sport-specific and similar. The only difference is in ACL injuries, where women have two to eight times the injury rate of their male counterparts. What accounts for this gender difference in the rate of ACL injury?
The potential answer includes a number of factors, most of which we cannot control:
Ligamentous laxity or joint “looseness” In general, most studies show that woman’s joints are looser than men’s.
Joint laxity can vary with the female hormonal cycle and there have even been hormonal receptor sites identified on the ACL. Female joints can be more “lax” at different times.
The anatomic alignment of the knee joint and the width of the area of the knee that the ACL lives in have also been implicated in the increased risk of ACL injury. Women have a wider pelvis than men and the alignment of their knees can be different. The “notch” where the ACL lives tends to be narrower in women. Men with similar alignments and notch widths, however, are not more prone to ACL injuries so it is not alignment or notch width alone that dictates the higher injury rate.
It is interesting to note that conditioning levels, previous athletic experience or skill level have not been proven to be factors in the incidence of ACL injuries.
One thing that may cause the difference in injury rates between men and women is muscle strength and recruitment. This has to do with the way women use their knees and muscles during athletics. Studies have shown that activation of the hamstring muscles in the back of the thigh are protective of the ACL during athletic activity. Women athletes tend to rely more on the quad muscles in the front of the leg and take longer to develop peak hamstring torque, or force during activity. Also, female musculature is weaker than that of a male even when normalized for weight and height.
Lastly, studies have shown that there is more motion in a female knee when landing during jumping and cutting activity.
A program of strengthening and biofeedback training where female athletes are taught and practice landing and cutting techniques can reduce ACL injuries. Indeed, several studies have documented decreases in ACL injuries from 14-72% in athletes enrolled in specific neuromuscular training programs with muscle strengthening and plyometric exercise.
While these types of programs cannot bring the occurrence of an ACL injury in women athletes to zero, they can be employed to help reduce their incidence. Since these injuries can be life-changing, they are certainly worth a try to keep women in the game.
The author is a member of White Plains Hospital Westchester Orthopedic Associates.
