What Is the Anterior Drawer Test for Your ACL?

The Anterior Drawer Test for anterior cruciate ligament (ACL) stability is a special test for your knee. It is designed to help you or your healthcare provider determine if you have sprained or torn your ACL. (A sprain is a tear to a ligament. The terms "ligament tear" and "sprain" are used interchangeably.) The Anterior Drawer Test is often used by your physical therapist or practitioner after a knee injury to test the integrity of your ACL.

Anatomy of Your Knee and ACL

Your knee is a complex hinge type joint that is comprised of the articulation of your femur (thigh), your tibia (shin bone), and your patella (knee cap). There are several muscular attachments that help move your knee joint. The major muscles around your knee are the quadriceps and the hamstrings. Many different ligaments help to provide support to your knee.

The ACL is a major ligament in your knee that keeps your shin bone from sliding and gliding forward in relation to your thigh. An injury such as a sprain to your ACL may cause significant knee instability and prevent you from participating in high-level sports that require stopping and starting, running, and jumping.

Symptoms of an ACL Tear

If you have injured your knee, there are several signs and symptoms that may indicate your ACL is sprained. These include, but are not limited to:

• Knee pain
• Swelling in your knee
• Difficulty bending or straightening your knee
• Difficulty walking or putting your weight on your leg
• A feeling of your knee giving out

If you suspect that you have torn your ACL, then you must see your doctor or healthcare practitioner right away. He or she can perform the necessary tests to determine the severity of your knee injury.

Perform the Anterior Drawer Test for Your ACL

To help you decide if your ACL is sprained, you can perform the Anterior Drawer Test. To perform the test, you must have another person like a friend or family member help you. Here is how you do it:

• Lie on your back with your injured knee bent and your foot flat on the floor.
• Have your friend sit gently on your foot so it does not move.
• Have your friend grasp your knee with her thumbs in the front of your knee and her fingers behind your knee. Your friend's fingers should be tucked up into the bent part of your knee and her thumbs should be on the front part of your upper shin.
• Have your friend gently pull your shin bone forward while watching how far it moves.
• Repeat the test on your healthy knee.

If your shin bone slides forward significantly more on your injured knee as compared to your uninjured knee, then you may have sprained or torn your ACL. You must see your healthcare provider immediately to confirm your suspicions.

Other Tests for an ACL Tear

If your healthcare provider performs the Anterior Drawer Test and it is positive, he or she may suspect an ACL tear and do other tests to confirm the suspicion. Other tests for ACL integrity include:

• The Pivot Shift Test. To perform this test, you need to lie down with your knee extended. Your practitioner then pushes in on the outside of your knee while holding your shin bone. As your healthcare provider pushes in on your knee, he or she slowly bends it. A positive test for an ACL tear occurs when your tibial plateau moves out of place and then into place when your knee is bent around 30 degrees. This test essentially slightly dislocates your knee and then relocates it.
• The Lachman Test. This test is done with your knee bent slightly at about 20 degrees. Your practitioner may rest his or her thigh under your thigh to get it to bend slightly. Then, your healthcare provider places his hand over your tibia while using his other hand to stabilize your thigh. A quick tug at your tibia is then done while monitoring for excessive motion at your joint line.

Here's one problem with these tests: they can be quite uncomfortable for you. When performing these tests, often times your knee will crunch and crack as it moves out of place. This can be quite uncomfortable and disconcerting. Still, they are both useful tests to see if you may have an ACL tear. Some research indicates that both the Pivot Shift and Lachman tests are more reliable tests for ACL injuries.

Next Steps to Confirm an ACL Tear

If your Anterior Drawer Test is positive, meaning that you suspect an ACL tear, you should go to your healthcare provider. He or she can perform more specific tests to confirm or reject the diagnosis. Tests that may be done to confirm (or rule out) and ACL tear may include:

• An X-ray to look for a fracture
• Magnetic resonance imaging (MRI)
• Computed tomography (CT) scan

The gold standard test to confirm an ACL tear is an MRI. The pictures from the MRI show soft tissue structures like muscles and ligaments. Your ACL (and other ligaments) can be visualized, and the pictures will likely show the status of the ligament.

Once your healthcare provider performs the Anterior Drawer test and confirms an ACL tear diagnosis with an MRI, he or she can recommend the best treatment for you. Various treatment options for an ACL sprain include.

• ACL repair surgery
• Physical therapy
• Using a knee brace

Of those options, a visit to your physical therapist is a reasonable first step in the treatment of your problem. He or she can give you strategies to work on improving your knee range of motion (ROM) and strength, and you can work on improving your ability to walk, run, and jump.

If you elect to have ACL surgery, you will likely benefit from physical therapy to help rehabilitate your knee after the procedure. Be sure to speak with your healthcare provider to help you decide on the right treatment for you.

A Word From Verywell

If you have injured your knee and suspect you may have sprained your ACL, then the Anterior Drawer Test may help you determine if your ACL is actually torn and if you need further medical care. It is a simple and often painless test to perform that can help you get the right care for your knee.