The anterior cruciate ligament is critical to keep the knee stable in aggressive pivoting sports like AFL football, netball, basketball and soccer. Its common mechanisms of injury are either a rapid pivoting movement, or a hyperextension injury. Hyperextension injuries occur on the sports ground, and in snowboarding & skiing. Reconstruction works well, but whilst returning to sport at 9 months is common, full strength probably occurs at 18 months – 2 years.
In football codes, injuries are more common in the earlier part of the season. This may be because the grounds are typically harder, giving greater grip, and higher forces on the knee.
Women seem to have a specific problem. In professional basketball, the incidence of injury is 0.07/1000 athletic exposures for men, and 0.23/1000 for women. Women need to be particularly cautious in the pre-ovulation part of the menstrual cycle (especially day 9-14 of the cycle) as the risk in that time seems to be more than three times the risk from day 15-28. Whether this relates to a hormonal effect on ligament or muscle strength, or another reason is unknown, but the finding is repeatable between studies. Oral contraception seems not to exert protection.
Prevention would be good!
An ounce of prevention is worth a pound of cure.
AFL, netball and soccer have all developed training guidelines designed to help prevent ACL injuries (and others). The soccer program (“FIFA 11+”) has been tested with many soccer teams, and for those clubs using the warmup at least twice a week had 37% less training injuries and 29% less match injuries.
A key part of each of these programs is learning good technique for running, jumping and landing. Some of the key tips are:
– pre-season strength training gives better control of the knee.
– with running, jumping and landing the knee should have minimal sideways movements. Being stable and level through the hips and pelvis helps with this.
– this becomes even more important when changing direction, and any sidestep should not be too wide.
– balance & unstable surface training such as wobble board & hopping exercises gives better control in unexpected circumstances.
– when landing & falling if the knee bends, the cruciate strain is reduced
All of these programs are available free online: