Nutrition and Fitness content presented in partnership with Sports, Fitness & Rehabilitation Center Online!

ACL INJURIES IN FEMALE ATHLETES

As female athletes increase in number of participants in sports, the issue of why ACL injuries occur more in females and especially how to prevent them is becoming a hot topic.

An NCAA study in the early 1990’s showed that female athletes are more susceptible to ACL injuries when compared to male athletes. This study revealed that females had four times the incidence of ACL injuries than males in basketball; three times more in gymnastics and two and a half more in soccer. 1The question was then why females were more susceptible.

Some injuries are inevitable due to the physical nature of these sports, but there exists a number suggested reasons women have more ACL injuries. These factors include: a narrower femoral notch; increased Q angle; increased ligament laxity; inadequate strength; and impaired neuromuscular coordination. Other factors to consider are the technique and skill of the player; improper shoe wear; and the type of playing surface. These all may contribute to incidents of injuries to female athletes.

The femoral notch is the space at the bottom of the femur through which the ACL runs. When doing comparative studies, it was found that this notch was narrower in females than males. Some feel that the tighter fit may cause a shearing effect on the ACL by the femur. "Q angle" is an abbreviation for the quadriceps femoris muscle angle. The normal angle in males is 13o and 18o in females.2 This angle is increased in females due to their wide pelvis. (See Figure below.)

Anatomically, a woman's knee is made with a naturally greater Q angle between the femur and the tibia, predisposing it to greater stress due to the torsion applied between the femur and the tibia. The increased Q angle also causes the feet to be more pronated and flattened.3 However, some have wondered if a pronated and flattened foot increases the Q angle. Whether or not the Q angle was the cause or result, recent studies have shown that custom-made, flexible orthotics will reduce pronation, put less stress on the knee, and improve the Q angle. The foot will also function better with a properly fitted orthotic because it will allow the key foot joint (subtalar joint) to function more effectively.4 The body will then require less effort for forward propulsion and provide for improved shock absorption.

Strength and agility training are also very important for female athletes. Boys have historically been trained from an early age in activities that increase their strength, agility and hand-eye coordination. Typically, young girls are at a disadvantage when they decide they want to play sports at an older age, because their lack of coordination and agility puts them at a greater propensity to injury.

Hormonal issues also are important in explaining a female athlete's susceptibility to injury. A lack of circulating androgens discourages the development of large and more powerful muscles, which act as a protective mechanism for the joints. Ideally, the quadriceps muscles should be twice as strong as the hamstrings. When there is an imbalance, the ACL is more susceptible to tearing. Also, estrogens increased during the menstrual cycle, increase the laxity in connective tissue, and may make the female athlete more susceptible to an injury during those times. The estrogens also provide more endurance, which will allow female athletes to put longer periods of stress on their joints. Because of the increased body fat ratio of a female, stress on the joints is increased.

The ACL is most often injured with a jump or an abrupt change in direction, which happens about seven times more frequently during a game or competition because of the increased intensity. Athletes who have injured the ACL usually describe it as a popping sensation, followed by swelling a couple of hours later, and a feeling that something is wrong. Today, with advanced surgical techniques and rehabilitation procedures, the recovery period for ACL injuries has been shortened.

A very recent study led by Bert Mandelbaum, M.D., Orthopaedic and Sport Medicine GroupTeam Physician, U.S. Soccer Men's National Team, endeavored to prove that special agility training could actually decrease the incidence of ACL injuries. They compared similar groups of female soccer athletes with a number of teams performing a specific training program and compared them to groups that were not participating in them. This study showed that female adolescent soccer players that participated in a neuromuscular and proprioceptive training program had a 74% decrease in ACL injuries. 5

In conclusion, it is a fact that women athletes are four to six times more prone to injuries of the ACL than male counterparts playing the same sports. Not to exclude male athletes, they do occur in male athletes and usually in an “unguarded moment” when fatigued from a lack of conditioning, so the same program helps reduce injuries in male athletes, but for a different reason. The biggest reason for more female injuries is due to anatomical differences, the Q angle being the most significant. If you are a female athlete, it's important that you have your feet checked for foot pronation problems and consider custom-made orthotics. Female athletes should also participate in a program of proprioceptive neuromuscular education including agility training. When these precautions are followed, women can participate in athletics with less susceptibility to injury.

Questions regarding proper proprioception and agility training as well as custom made orthotics can be answered through Sports, Fitness & Rehabilitation Center / G-Force Training at 714.854.7606

References

1. Knee injury patterns among men and women in collegiate basketball and soccer. Elizabeth Arendt, MD and Randall Dick, MS. American Journal of Sports Medicine, Vol. 23, No. E, 1995.
2. Illustrated Orthopedic Physical Assessment, 2nd edition. Ronald Evans, p. 804, St. Louis, Missouri, Mosby Inc., 2001.
3. The Lower Extremity and Spine in Sports Medicine, volume 2. James A. Nicholas and Elliot B. Hirshman, p. 1567 & 1540, St. Louis, Missouri, Mosby, 1995.
4. The effect of the quadriceps femoris angle with the insertion of an orthotic device. D. Robert Kuhn, DC, DACBR; Anton Cherry, BSc; Michael Golab, BSc; Sean Rodgers, BSc. Accepted for publication.
5. Presented at the 2002 American College of Orthopedic Surgeons

Sports, Fitness & Rehabilitation Center
5107 Richfield Rd., Yorba Linda, CA 92886
email: drpierra@sfrc.us 
web: www.sfrc.us
Ph:714.854.7606 // Fax: 714.854.7607