Though you will most likely be in pain, try to remember the exact sound your knee made. Describing the noise your knee made can actually help your doctor to diagnose your injury.

When you suffer a partial tear of your ACL, the pain receptors in your knee get activated. This can lead to a moderate to severe pain.

You should also take note if your knee becomes swollen after any time you do a physical activity. While you may not have noticed the swelling right after your accident, swelling after physical activity is a definite sign that you knee has been injured and could be partially torn.

Even if you can walk, your knee will most likely feel weak.

Suddenly changing direction. Suddenly stopping while you were in motion. Having a heavy force or pressure put on your knee, such as when colliding with someone in football. Jumping and landing incorrectly or awkwardly. Suddenly slowing down when running.

You engage in athletic sports that involve the active use of your legs. Sports that involve physical contact can also increase your chances of ACL injury. You experience muscular fatigue. Muscular fatigue can also make a person prone to ACL injury. Since the muscle works together with the bones, ligaments and tendons, exerting your muscles and making them tired can lead to a higher risk of injury. For example, a tired soccer player is more susceptible to ACL injury than an energetic player who has just started playing. You have a medical condition that causes you to have weak muscles or bones. For example, having weak and brittle bones, having ineffective development of your cartilage, or being obese can all increase your chances of an ACL tear.

Schedule an appointment for as soon as possible after the injury. If you can, you may also go to the hospital to deal with the injury right away.

A grade 1 ACL sprain involves mild injury to the ligament. It has been slightly stretched but not torn. It can still sustain the knee joint and will help the leg remain stable. A grade 2 ACL sprain is when the ligament is stretched beyond its capacity to the point it becomes loose. This is when the technical term “partial tear of the ACL” is used. This can mean that part of the ACL is torn but the majority of it is intact; or that one of the bundles is torn but the other is intact. In the former, surgery may not be required, but in the latter, it will likely be necessary. [8] X Expert Source Jonathan Frank, MDSports Orthopedic Surgeon & Joint Preservation Specialist Expert Interview. 1 October 2020. A grade 3 ACL sprain makes the knee joint unstable and the ligament is completely torn apart.

Have you lie down on a table. Your doctor will first look at your uninjured knee to see how far your shin moves forward when your knee is bent. Your ACL keeps your shin from moving very far forward. Your doctor will then look at your injured knee and see how far your shin moves forward when the knee is bent. If it moves forward further than normal but your doctor can still feel resistance, it means that you have a partial tear. If there is no resistance, your ACL has been fully torn.

Straighten your leg while simultaneously press inward against the outer part of your knee and twist your leg outward. Doing this will show how well your ACL is functioning because it is a movement that only involves the ACL. Your leg will be slowly bent while continuous pressure is put on it. When your knee is bent at a 20 to 40° angle, your doctor will look at your shin bone. If the bone slides forward a bit it means that your ACL has been partially torn. If you have a partial tear, where the majority of the ACL is still intact for both bundles, then that pivot shift will be negative. [11] X Expert Source Jonathan Frank, MDSports Orthopedic Surgeon & Joint Preservation Specialist Expert Interview. 1 October 2020.

All three of these injuries are associated with a partial ACL tear.

Your doctor might also request an oblique coronal image if he or she is still not sure about the extent of your injury. This image will give the doctor a better view of your knee in addition to the MRI.

Your doctor might give you crutches to use along with your brace. Crutches are used to keep you from putting pressure or too much weight on your knee while it heals.

If you are lying down, prop your knee and leg up so that it is above your heart and chest.

Any amount of time shorter than 15 minutes will not do much to control swelling or pain. Keeping the ice on your knee for longer than 20 minutes may result in the ice burning your skin.

Talk to your doctor about the best option for your specific case.