Tuesday, December 4, 2007

Knee Anterior Ligament (ACL) Injury And Rehab

A knee anterior cruciate ligament (ACL) injury is the most common injury affecting the knee joint. About 70% of all serious knee injuries involve damage to the ACL. And, about 80% of these injuries occur without any contact from another player.

There are some training techniques you can use to lessen the risk of this injury. The knee ACL is located within the capsule of the knee and connects the thigh bone (femur) to the shin bone (tibia). Pictured below is a torn knee ACL:

Most ACL injuries occur when the athlete decelerates, comes to a sudden stop or lands with improper technique while placing too much stress on the knees. The athlete should dominate the hamstrings, hips and glutes during movement. The hips are often under-used during sports competition.

Another common mechanical breakdown is when the knees protrude far in front of the feet when decelerating, landing or squatting. This puts undue stress on the knees and often causes injury. Also, when the quadriceps are much stronger than the hamstrings, this can cause an ACL injury. Research has shown that the hamstrings play an important role in stabilizing the knee and protecting the ACL during deceleration.

Females injure their ACLs at six times the rate of males. Females demonstrate a lower hamstring to quadricep ratio. This means they typically have weaker hamstrings compared to males. They also demonstrate different muscle activation patterns compared to males.

Females are typically quadricep dominant athletes which means they use their strong quadriceps muscles and do not use their weak hamstrings enough.
Strength training for females should be adjusted to adequately strengthen the hamstrings.

Lateral lunges and lateral bounding teaches the athlete how to move correctly while dominating movement with the hips.

You should also learn proper landing techniques using exercises such as vertical jumps, broad jumps and depth jumps.

Surgery will be necessary for a tear of the ACL. Usually, the tear is repaired by using a part of another healthy ligament to replace the damaged ACL. Rehabiliation for a torn ACL takes about 3-4 months and it takes 8 months or more before you can return to competition.

In part 3 of this series, I will look at hamstring injury prevention.

Mark Dilworth, BA, PES
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  1. Luckily I have had no problems with my knees. My ankles are another story though, posterior tibialis tendonitis is keeping me from my routine and ticking me off.
    Love the blog btw!

  2. It is most common that men and woman have knee problems.It is also the degeneration of the bones that crops problems for the knee.

  3. Hi there,
    It was great information for knee problems.I shall tell my grany.