Got Knee Pain? Here Are Some of the Most Common Injuries That Can Cause Pain

If you’re like most adults, you’ve experienced knee pain at some point in your life. It’s a very common issue, accounting for almost four million primary care visits to doctors each year, and it’s due to a lot of different factors. 

“Our knees are the big movers of our legs. They help us get in and out of chairs, up and down stairs, and walk on anything that isn’t flat,” says Cody Anderson, PT, DPT, a physical therapist at Hinge Health. “They carry a lot of resistance and load throughout our lives.”

But just because knee pain is common doesn’t mean it’s inevitable or untreatable. Here’s a guide to understand some of the most common knee injuries and how to recover from and prevent knee pain from flaring in the future. 

To understand the most common knee injuries and conditions, it helps to get a primer on the anatomy of your knee. Here’s a look at its key components:

• Bones. Three bones make up the knee joint: the femur (thigh bone), the tibia (shin bone), and the patella (kneecap).

• Articular cartilage. This is a slippery substance found at the ends of the thigh bone and shin bone, and at the back of the kneecap. It helps the knee bones glide across each other whenever you move your leg.

• Meniscus. This tough, rubbery substance helps cushion and stabilize the knee joint. It also acts as a shock absorber between the thigh bone and shin bone.

• Ligaments. Ligaments are like strong ropes that hold your knee bones together and help with stability. The major ones in the knee include: 

  • Collateral ligaments are on the sides of the knee. The medial collateral ligament is on the inside, and the lateral collateral ligament is on the outside.

  • Cruciate ligaments are inside the knee joint and control front and back movement of the knee.

• Tendons. These connect muscles to bones. There are two main ones in the knee:

  • The quadriceps tendon connects the muscles in the front of the thigh to the kneecap.

  • The patellar tendon connects muscles from the kneecap to the shin bone.

“As you can see, the knee is a very complex joint,” explains Dr. Anderson. And although it’s an incredibly strong and resilient joint, it’s used in a lot of everyday activities, which means it can be prone to some pain and injury at times. 

Common Knee Injuries

A knee injury can affect any of the ligaments, tendons, bones, and cartilage around your knee joint. Some injuries, like osteoarthritis, develop gradually and — for some people — contribute to symptoms over time. Other knee injuries make themselves apparent more quickly, such as: 

• Dislocated knee. Most of the time, this is not a true knee dislocation but is rather due to the kneecap slipping out of place, says Dr. Anderson. It’s usually caused by trauma — like a fall when skiing or a collision during a sports game. 

• ACL injury. ACL injuries usually involve a tear of your anterior cruciate ligament (ACL), which connects the shin bone to the thigh bone. They’re most common among athletes who play sports that require sudden changes in direction, like basketball or soccer. “Making sure you address an ACL injury can help ensure you regain and maintain knee stability in the future,” says Dr. Anderson. 

• PCL injury. This is damage to the posterior cruciate ligament (PCL), the ligament located inside the knee just behind the ACL. PCL injuries are much less common than ACL injuries, and they usually happen because of a major trauma, like a car crash.

• Meniscus tear. These can be common, says Dr. Anderson, and often happen from a twisting or pivoting movement (usually when playing sports). But they can also occur for no apparent reason. Menisci change with age, just like articular cartilage and other structures in the body. While those changes are not necessarily harmful, they can contribute to injuries like meniscus tears as you get older.  

• Tendon tears. Certain sports or activities can cause the quadriceps or patellar tendons to be stretched and torn, resulting in pain. 

• Knee fractures. Fractures involving the knee can happen during something like a fall or an auto accident, says Dr. Anderson. 

When to See a Doctor

Knee pain can be scary and troublesome, especially if you took a fall or had an accident recently. So how do you know if knee pain is considered serious?  

There’s no hard and fast rule, but in general, if your knee pain comes on slowly or it appears to be related to doing a new activity (or increasing the frequency or intensity of an activity), you should be okay to try and manage your symptoms at home. It may help to scale back on your activity level for a short period of time and focus on gentle movement, stretching, and strengthening exercises and monitor your progress. 

But if you experience sudden knee pain accompanied by any of the following, you may need to see your doctor: 

• Significant swelling, redness, and/or tenderness around your knee joint

• Pain so intense you can’t put weight on your knee

• Pain accompanied by fever 

• A popping noise at the time your knee was injured

• Your knee locking up on you that prevents you from moving the joint 

• Bruising around your knee that extends into your upper calf or shin 

Knee Pain: Best Treatments

There are a lot of different ways you can manage and treat knee pain. Some of the most common ones include:

• Physical therapy. A PT can work with you to strengthen your knee muscles to help reduce your pain and improve function. Physical therapy can be especially effective in helping you avoid surgery for certain injuries, like an ACL tear, but it can also be highly effective in preventing future knee pain flares and injuries. You can see a physical therapist in person or use a program like Hinge Health to access a PT via telehealth/video visit.   

• Over-the-counter (OTC) medication. Pain relievers such as ibuprofen (Advil, Motrin), naproxen (Aleve), and acetaminophen (Tylenol) can be helpful for knee pain. It’s important to make sure that you are safely able to take these medications, based on your medical history.

• Ice and heat. Icing reduces swelling and inflammation and can help acute and chronic knee pain. Heating increases blood flow and can reduce stiffness. You can apply either heat or ice as needed for 20 minutes at a time, but avoid using heat to treat a new injury as this may delay healing. 

• Compression and elevation. To manage swelling, you can use a brace or wrap around your knee and elevate your leg so your foot is above your heart.  

Physical Therapy Tips for Knee Injuries

Even if you haven’t had an injury but have been dealing with persistent knee pain, physical therapy can help strengthen surrounding knee muscles and prevent future injuries from happening. During PT, you’ll likely work on: 

• Stretching. This can help with any muscular imbalances that may have contributed to your knee injury, says Dr. Anderson. Note that you may be advised to avoid bouncing stretches — where you use a bouncing movement to push your body past a comfortable range of motion — at first. Some good stretches include a quad stretch, a hamstring stretch, and the runner’s (calf) stretch.

• Strengthening. Your exercises will gradually become more challenging. Some people might start by performing exercises with a straight knee, like straight leg raises, and progressing to exercises that require some degree of knee bending, like squats. If you’re an athlete or work out regularly, this work is even more important. Research suggests that the best way to prevent injuries is to include a combination of dynamic stretches, agility work, strength training (including the core), and even plyometrics (jumping activities) into your exercise routine. 

A Note on Movement 

Moving through knee pain can be scary, and it's understandable to want to avoid any activities that may cause discomfort. Know this: Movement is medicine when it comes to knee pain. Inactivity can actually make the pain worse over time as muscles weaken and the joint stiffens. By taking an active approach to managing your knee pain, you can improve your overall health, prevent future pain flares, and get back to doing what you love. 

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. Bunt, C. W., Jonas, C. E., & Chang, J. G. (2018). Knee Pain in Adults and Adolescents: The Initial Evaluation. American Family Physician, 98(9), 576-585. 

2. Beutler, A. (2022, July 27). Patient Education: Knee Pain (Beyond the Basics). UptoDate. https://www.uptodate.com/contents/knee-pain-beyond-the-basics/print

3. Mulcahey, M. K. (2022, February). Common Knee Injuries. OrthoInfo — American Academy of Orthopedic Surgeons. https://orthoinfo.aaos.org/en/diseases--conditions/common-knee-injuries/#:~:text=The%20most%20common%20knee%20injuries%20include%20sprains%20and%20tears%20of,)%2C%20fractures%2C%20and%20dislocation.

4. Ibeachu, C., Selfe, J., Sutton, C. J., & Dey, P. (2019). Knee problems are common in young adults and associated with physical activity and not obesity: the findings of a cross-sectional survey in a university cohort. BMC Musculoskeletal Disorders, 20(1). doi:10.1186/s12891-019-2487-2

5. Arundale, A. J. H., Bizzini, M., Giordano, A., Hewett, T. E., Logerstedt, D. S., Mandelbaum, B., Scalzitti, D. A., Silvers-Granelli, H., & Snyder-Mackler, L. (2018). Exercise-Based Knee and Anterior Cruciate Ligament Injury Prevention. Journal of Orthopaedic & Sports Physical Therapy, 48(9), A1–A42. doi:10.2519/jospt.2018.0303