How Do You Injure Your Anterior Cruciate Ligament?


Okay, so WHAT is the anterior cruciate ligament first?

Shortened to ‘ACL’, this ligament is one of the most important ligaments on the knee. Why? Well, it stops abnormal movement of the lower leg (tibia) sliding forward and importantly twisting relative to the upper leg (femur).

People who’ve ruptured their ACL know how just how important it is, twisting and turning becomes virtually impossible, particularly at speed and you don’t have to be playing sports to see the symptoms. A person may twist at the bottom of the stairs and suddenly collapse to the ground.

The major symptom of ACL injury is instability. Sure, it hurts when you injure it, but if the knee is left to settle and there’s no other injury inside the knee, pain isn’t usually a problem.

The injured person, however, becomes very aware of rotational movements and will avoid them at all costs on the injured leg as they just won’t be able to stay upright!

Way back when I was doing my clinical training, my supervisor used a great analogy to illustrate this familiar problem to his patients:

“You could run in a straight line for England, but as soon as you turn you’d drop to the floor”

HOW is this ligament injured?

It’s such a common injury, especially in females. Did you know females are 2-5 times more likely to rupture their ACL compared to male counterparts? Shocking eh? What’s more shocking is that we’ve known about this for over 20 years and still we’re trying to find out the reasons why. Indeed some of my own research has tried to address some of the issues.

Anyway, there are over …. ACL Injuries per annum and given it’s frequency you’re likely to have seen one happen if you watch a lot of sport, or indeed maybe you’ve sustained one yourself (I have). These injuries most commonly happen in sports such as football, basketball, handball, skiing, rugby, motorcross.

The classic mechanisms include:

Weight-bearing (foot just planted on the ground, landing, running etc)
Sudden twist/rotation

If you’re keen to see one, here’s a clip on YouTube

What happens next:

Person falls to the floor
People nearby may hear a loud ‘POP’
Massive swelling develops in the knee almost immediately

May happen afterwards

Person goes to casualty
Blood is drawn off the knee
An X-ray is taken and person is discharged told there’s nothing wrong
Sorry, the last one is a bit of a joke. So many injuries like this used to be missed because people didn’t know about them. Thankfully it’s not so common now.

Treatment will vary depending on the severity of the injury and what the person wants to do afterwards, for example, if they’re willing to give up or reduce ‘unpredictable’ sporting activities. The clinician will do several tests (Lachman, pivot shift, anterior draw) to judge how badly the ACL is injured.

Usually surgery is required to reconstruct the ligament. There are several choices of graft that can be used and the options should be discussed with the patient.

I’ll cover more on this another time and some of the options if you’ve suffered an ACL injury.

Questions..? See the Get Better page for a preview of the Get Back to Sport ACL rehabilitation programme.

Injured?  Get in touch for a free consultation.