The following is a summary of an article by Traina and Bromberg in Orthopedics Vol 20 No 6 June 1997

In the NCAA, the Injury rates are 2.4X greater in soccer and 4.1 X greater in basketball for female athletes. The reason for this increase is still speculative, but there are several theories under investigation.




These theories are:

Extrinsic
      Conditioning
      Body Movement
      Muscular Strength


Intrinsic
      Joint Laxity
      Notch Width
      Limb Alignment




Extrinsic

Conditioning
Many authors feel that the novice female athlete is introduced to activities beyond her physical conditioning. At the US Navel Academy the females have reduced their injuries with a conditioning program

Body Movement
Most ACL injuries are do to non-contact jumping mechanisms.

      Planting and cutting 29%
      Straight knee landing 28%
      Landing with knee hyperextended 26%

Training the female athlete to modify the landing to a flexed knee reduced the % age of ACL injuries.

Muscular Strength
Woitys has shown that there are gender differences in muscle strength, muscle recruitment order, and hamstring peak torque times.

The implication here is to emphasize hamstring strength to protect the ACL

Intrinsic

Joint Laxity
There are contradicting studies on the differences in ACL laxities. Daniels study with the KT-1000 showed no differences.

However the integrity of the connective tissue is believed to reflect the hormonal melieu. When estrogen rises, so does relaxin. This results in increased laxity of all connective tissues and make the ACL more susceptible to injury.

Limb Alignment
Ireland has described the wider pelvis, increased femoral anteversion, and the genu valgum, with decreased muscular support as possible causes for the increased ACL injury rates.

Notch Width
It has been documented that women have a smaller notch than men. It has also been reported that athletes who sustain ACL injuries have a narrow notch. It may well be that the narrow notch is only an indication of a small incompetent ligament. Evidence for this is seen after notchplasty where the notch will fill in around the new ligament graft.





Conclusion

At the present time the best advice to give the female athlete is to be well conditioned and land with a flexed knee.