The Anterior Cruciate Ligament (ACL) is one of the 4 main ligaments in your knee. Damage can occur when your knee suddenly hyperextends, meaning it goes beyond straight forcefully. Your quad and hamstring muscles support this ligament and must be in tip top shape if you’ve had a strain, or better yet, to prevent one! Learn advanced exercises here!


In that the ACL is one of only 4 ligaments for your knee, damage to it can leave your knee vulnerable. When you straighten or extend your knee all the way, the ACL keeps it from going too far. The VMO, a part of your quad muscle, is the muscle that actively assists this limit and is very important when it comes to stabilizing your knee. Your knee needs to feel comfortable and be in control as it approaches full extension. Good strength in your knee can help prevent an ACL strain, and is paramount in protecting yourself from additional injury if you’ve already damaged your ACL. The exercise in the free tip is a bit challenging, but is truly what you need to be able to do to have the confidence that your knee is protected. The full knee program will fill in the gaps and provide you will well rounded strength and flexibility.


Video Transcript: ACL Strain
The ACL is one of 4 main ligaments in your knee. A ligament is like a piece of elastic that holds 2 bones together. The ACL keeps your knee from hyperextending, or going too far past straight. An ACL strain can occur when your foot slips out in front of you too quickly, when you miss a step, jump or kick forcefully, or land with your knees straight, or if something slams into the front of your knee and forces your knee back. These things happen sometimes unavoidably, so you must have good strength and proprioception in your quad to protect your knee from extending too far too quickly. The VMO is the tear drop shaped muscle that is the part of your quadriceps closest to your knee cap. The VMO is doing it’s best work when your knee is very close to being straight, between about 15 degrees of knee bend to straight, so to strengthen it you must fully extend your knee. This muscle helps support the ACL, track your kneecap in the right groove, and keeps your knee from buckling. Hi, I’m Josie, the licensed physical therapist that created insight into injury. And I want to teach you today the number one exercise to avoid an ACL strain. The single leg mini squat. This exercise is a bit complicated but proper technique is important whenever you’re trying to avoid an injury. I’d suggest you stand in front of a mirror and have something sturdy to hold on to to help with balance if needed. Basically you’ll be standing on one leg and bending that knee about 15 degrees, then fully extending it, repeating it 10 times. There are a few pointers that make or break this exercise though so please pay attention. You should feel your body weight distributed evenly throughout your foot, slightly favoring your heel rather than your toes. As you bend your knee, your hips should translate backwards, rather than your knee sliding forward. Your knee should never end up in front of your toes. When looking down at your foot, or in the mirror, your knee should never be any more towards the inside than your big toe – keep your kneecap in line with the middle of your foot. You don’t have to squat very low- the important part is fully extending your knee with good control. It will probably only take a few of these to make you feel like you’re getting a good muscle burn in your lower quad muscle if you’re doing it right. Having good strength when fully extending your knee, and doing so with good control is a way to train your knee to stay in control if your knee is on track to hyperextend like with a sudden slip and fall. This exercise is also a very important one to do if you are recovering from an ACL injury. Please check out the full length PT session where I break the exercise program down into step by step instructions and give you all the ins and outs of what to expect during recovery, and why each exercise is important for good knee health. Thanks!