Understanding Knee Ligament Injuries: Common Causes and Exercises for Relief

Knee ligament injuries can happen to anyone. While you may often hear about professional athletes injuring knee ligaments, like their ACL or MCL, these types of injuries can occur in everyday life too. Since your knees are vital to almost everything you do — getting out of bed, walking, bending, climbing stairs, getting in and out of your car — knee injuries can make life challenging.

Unlike some injuries like runner’s knee or jumper’s knee that develop over time, knee ligament injuries tend to be sudden, acute injuries tied to a specific action. They’re often referred to strains, sprains, or tears, which can sound scary. But know this: Knee ligament injuries are treatable — often without surgery — and you will be able to get back to doing activities you enjoy.

Read on to learn more about the different types of knee ligament injuries, what causes them, and how to prevent and treat them, including with exercises recommended by Hinge Health physical therapists.

What Are Knee Ligaments?

Ligaments are short bands of tough, connective tissue that connect two bones or hold together a joint. Unlike muscles and tendons that are involved in movement, ligaments work to stabilize joints. “They help prevent movement you don’t want, like overextending your knee,” says Alec Martinez, PT, DPT, a physical therapist at Hinge Health. Think of ligaments like a safety net to protect you from injury.

Your knee has four main ligaments. The first three ligaments connect the femur (thigh bone) to the tibia (shin bone), while the fourth one connects the femur to the fibula (the smaller bone in the lower leg). Despite some similarities, these ligaments have different functions.

• Anterior cruciate ligament (ACL), the most frequently injured knee ligament, controls rotation of your knee and prevents the tibia from moving too far forward.

• Posterior cruciate ligament (PCL) prevents the tibia from moving too far backward.

• Medial collateral ligament (MCL) prevents your knee from moving too far inward.

• Lateral collateral ligament (LCL) prevents your knee from moving too far outward.

Together, these knee ligaments offer full knee protection and ensure knee joint alignment during activities like running, jumping, and pivoting.

Knee Ligament Injury Symptoms

Since the job of ligaments is to stabilize joints, they are quite strong. But they aren’t invincible. Knee sprains can happen, which is when ligaments are overstretched or torn. 

Below are common symptoms of a knee ligament injury. Symptoms can vary, especially in intensity, depending on the severity of your injury. Some symptoms are unique to the ligament that’s injured.

• Sharp knee pain at the moment of injury

• Pain or soreness at the back of your knee (PCL), inside of your knee (MCL), or on the outside of your knee (LCL)

• Feeling or hearing a popping sound when the injury occurs

• Swelling in the first few hours after injury

• Stiffness or loss of range of motion

• Difficulty walking or bearing weight on your injured knee

• Sense of instability or looseness in your knee

• Feeling like your knee is going to give out or having your knee give out

Common Causes of Knee Ligament Injuries

Here are common causes of knee ligament injuries, particularly sprains. (Most knee ligament injuries are sprains, but sometimes, in more serious cases, it can be a rupture in which the ligament is completely torn.) 

• Too much twisting. This is a common cause of ACL injuries. “We refer to this as a stand-and-pivot injury,” says Dr. Martinez. “It occurs when your foot gets stuck on the ground and your knee twists over it, causing a large force in the ligaments.” It can occur when skiing or playing football, tennis, basketball, pickleball, or soccer. 

• Direct impact. Being hit in the knee while playing sports like football, soccer, or hockey can cause knee ligament injuries. This can also occur in a car accident.

• Minor trauma. Even less forceful impacts, such as falling on your knee, may result in a ligament injury. Other minor traumas include stepping off a curb and landing wrong, slipping on a wet surface, or stopping abruptly. “Anytime there’s an acute strain that is more than the muscles can protect against, or when your muscles are not actively able to provide support, knee ligaments can get strained,” says Dr. Martinez.

• The unexpected. Stumbling when you’re on an uneven surface or hiking, a rapid change in direction, or awkwardly twisting your leg when playing with a child could lead to a knee ligament injury. “Any situation where things happen quickly and you don't have the ability to set yourself into alignment are a perfect storm for knee ligament injuries,” says Dr. Martinez.

These exercises will help ease knee pain, promote recovery, and protect you from future knee ligament injuries. If you’re reluctant to exercise with a knee ligament injury out of fear you’ll do more harm, know that movement is often the fastest way to healing. “Inflammation is part of the healing process, sending fluid and nutrients to the injured area. But it can also increase pressure, which can be painful,” says Dr. Martinez. “Regular movement and exercise can ensure good circulation, so fluid moves in and out of the knee joint to prevent too much pressure and discomfort.” Exercise also strengthens the muscles around your knee to ease stress on the ligaments as they heal. 

The information contained in these videos is intended to be used for educational purposes only and does not constitute medical advice or treatment for any specific condition. Hinge Health is not your healthcare provider and is not responsible for any injury sustained or exacerbated by your use of or participation in these exercises. Please consult with your healthcare provider with any questions you may have about your medical condition or treatment.

Treatment Options for Knee Ligament Injuries

Most knee ligament injuries can be treated without surgery. And, in many cases, conservative treatment options, like the ones below, can get you back to doing all the activities you enjoy. 

• Physical therapy. Physical therapy is a research-backed treatment for knee ligament injuries. Using targeted exercises, like the ones above, and neuromuscular stimulation (low-level electrical impulses that cause muscles to contract), a physical therapist (PT) can help you rebuild strength and function in the surrounding knee and leg muscles. You can see a physical therapist in person or use a program like Hinge Health to access a PT via telehealth/video visit.

• P.E.A.C.E and L.O.V.E. protocol. This new self-care model is more comprehensive than the R.I.C.E. (rest, ice, compression, elevation) approach for knee ligament injuries, and prioritizes movement and exercise over rest. “While you don’t want to overdo it, movement is the best medicine,” says Dr. Martinez. “The more you isolate your body, the more atrophy occurs in surrounding muscles and the more swelling tends to accumulate because there’s less circulation in the area.”

• Ice and heat. Icing can help reduce swelling and pain immediately following a knee ligament injury. Heating increases blood flow and can reduce stiffness. You can apply ice or heat as needed for 10 to 20 minutes at a time, but avoid using heat to treat a new injury, which may delay healing. 

• Knee bracing. Bracing is more often recommended for PCL and LCL injuries. Evidence for its effectiveness after an ACL or MCL tear is inconclusive. No matter what type of injury you have, you should follow your doctor’s or PT’s advice when it comes to braces. Sometimes, a knee brace can help you to be more active, which promotes healing.

5 Tips to Prevent Knee Ligament Injuries

While you may not always be able to prevent an injury from happening, you can reduce your risk and minimize the severity of a knee ligament injury with these tips.

• Ease into activity. Dynamic warm-ups prepare your body for activity and have been shown to reduce injury. To warm up your lower body and knees, do exercises like butt kicks, side shuffles, high knees, and squats for five to 10 minutes.

• Use the right gear. You should wear properly fitting, sports-specific footwear for activities like pickleball, soccer, tennis, or basketball. Activities with lots of side-to-side movement and quick changes in direction require shoes with lateral support to reduce your risk of injury. Running shoes won’t cut it for these sports. If you’re a skier, make sure your bindings are properly adjusted.

• Practice good technique. There are many ways to move your body, and you should do whatever works for you. But your movement mechanics may help prevent a knee ligament injury during certain activities like downhill skiing, soccer, tennis, or pickleball. Lessons can be helpful if you’re new to an activity. Even if you’ve been doing a sport for a while, a refresher lesson may help. A physical therapist can also provide sport-specific recommendations.

• Exercise regularly. You’re more likely to get injured if you’re inactive during the week and then go out and play hard on the weekend. “Exercise increases the resiliency of tissues, including improving the strength of ligaments and muscles for better stability in the knee,” says Dr. Martinez. “It also trains your neurological system to make adjustments as you’re doing activities to avoid too much strain on ligaments.” Include a combination of dynamic stretches, agility work, strength training (including your core), and plyometrics (jumping activities) in your workouts to protect your knees.

• Get rest. This includes regularly getting a good night’s sleep and allowing recovery time in your workout routine. You’re more susceptible to injuries when you’re fatigued or overtraining.

PT Tip: Avoid Sitting Still

“Being static and over resting is one of the things I've seen that increases people’s pain over time,” says Dr. Martinez. “Movement is the best medicine with any sort of knee ligament injury.” This includes targeted exercises for the injured area, like those above, and general, everyday activity.

How Hinge Health Can Help You

If you have joint or muscle pain that makes it hard to move, you can get the relief you’ve been looking for with Hinge Health’s online exercise therapy program.

The best part: You don’t have to leave your home because our program is digital. That means you can easily get the care you need through our app, when and where it works for you.

Through our program, you’ll have access to therapeutic exercises and stretches for your condition. Additionally, you’ll have a personal care team to guide, support, and tailor our program to you.

See if you qualify for Hinge Health and confirm free coverage through your employer or benefit plan here.

This article and its contents are provided for educational and informational purposes only and do not constitute medical advice or professional services specific to you or your medical condition.

References 

1. Knee Ligament Injuries: Causes, Symptoms & Treatment. (n.d.). UW Medicine. Retrieved from https://www.uwmedicine.org/conditions-symptoms/bone-joint-muscle/knee-ligament-injuries

2. Ligament Injuries to the Knee. (2019). John Hopkins Medicine. https://www.hopkinsmedicine.org/health/conditions-and-diseases/ligament-injuries-to-the-knee