ACL injuries are very common among athletes. An ACL injury is most often a non-contact injury in which the knee is forced into hyperextension or twists when landing a jump or while cutting. Due to the cause of injury, proper strengthening, balance training, and jumping and cutting mechanics are recommended to decrease the risk of tearing an ACL.
Females are at more risk for ACL injuries because:
- Females tend to land with knees straight and angled in.
- Females have wider hips causing increased lateral, sideways pull on the kneecaps.
- Females tend to have decreased hamstring strength.
- Females tend to pivot with decreased hip and knee bend.
- Females tend to stop from a sprint with knees straight using primarily their quads versus their hamstrings leading to forward translation of the lower leg.
- Females tend to have decreased endurance.
To avoid ACL injuries, it is recommended that athletes work on strengthening their quads and hamstrings. They can do so by specifically working on a proper squat form to include: knees over balls of feet (not in front of toes), chest over knees and avoiding a “knock knee” position. It is important that the athletes learn to control knee hyperextension, especially when landing jumps and pivoting. Enhancing balance, proprioception, and incorporating core strengthening are very important aspects of training that are often overlooked.
Poor landing technique from a jump has been found to place individuals at a higher risk for ACL injuries.
A proper landing technique from a jump includes:
- Soft landing
- Knees bent at less than 45 degrees
- Land on toes and rock back to heels
- No knock knees
- Knees behind toes
- Instant recoil (preparation for next jump)
- Avoid knee hyperextension on recoil
If the athlete is landing with the knees straight or in front of the toes, they are overusing the quads and not applying the hamstrings appropriately. This places the force on the front of the knees. Hamstring strengthening would be recommended in this case.
If the athlete demonstrates a “knock knee” landing and take-off they should strengthen the gluteus medius and work on hip and trunk stabilization.
The athlete is demonstrating leg dominance if they tend to land with one leg in front of the other and this suggests a need to strengthen the non-dominant leg for symmetrical leg strength.
By Tiffany Whitney, PT