Is the Knee the Most Commonly Injured Joint in the Body?
The knee is the largest joint in the human body and one of the most complex. Because it is used in so many daily activities, it's prone to a variety of injuries. Indeed, knee injuries rank at the top of statistics for the most common musculoskeletal injuries.
- Knee injuries were the most common of all reported musculoskeletal injuries in 2012 (accounting for 10% of all reported injuries), according to the National Center for Health Statistics.1
- In the US, there are between 100,000 and 200,000 ruptures per year of the anterior cruciate ligament (ACL), the most commonly injured knee ligament.2
- More than 2 million individuals were diagnosed with patellofemoral pain in the period from 2007-2011.3
Why are there so many Knee Injuries?
The knee is one of the most active joints in the body, whether we're walking, running, lifting, squatting, riding a bicycle or simply standing still. It might seem like a simple hinge, but the knee joint must be able to bend and rotate with every movement, often while bearing most of our weight.
The knee is composed of three separate areas, or compartments: the medial, the lateral and the patellofemoral - each of which is lubricated and cushioned by cartilage and stabilized by ligaments and tendons as we move. Over time, the repeated actions and stresses our knees go through can take a toll, causing the parts of the knee to wear and break down. Injuries can also be the result of sudden impact or movements, such as twisting, pivoting or stopping while playing sports, or simply stepping off a curb.4
Some of the Most Common Knee Injuries
Of the four ligaments of the knee joint, perhaps the most well-known in regard to injury is the anterior cruciate ligament (ACL). The ACL can rupture during athletic activities that require quick cutting, running, and jumping movements.
Patellofemoral syndrome, also known as Runner's Knee, is a knee injury that can cause pain around your knee cap. This syndrome can worsen gradually over time due to overuse, or be the result of a traumatic fracture (from a fall or a car accident, for example).
Another often injured part of the knee is torn cartilage such as the Menisci, which are C-shaped pieces of cartilage that function as "shock absorbers" between the tibia and femur. The Menisci may be torn in a fall or from participating in a sports activity. The Menisci may also be damaged because of weakening and degeneration due to aging and osteoarthritis.
Ways to Help Prevent Knee Injuries
- Maintain your weight, to decrease stress on your knees and reduce chances for knee injuries.
- Wear sensible shoes that fit properly, for better balance and alignment.
- Warm up with stretches and light exertion before starting exercise.
- Do low-impact exercise. Elliptical trainers, rowing or step machines offer exercise without the stress of running.
- Swim or walk, for exercise with lower joint stress.
- Weight train. Well-toned leg muscles help support your knees and avoid injury. Consult with an expert first on proper technique.
- Don't decrease your activity, because it can lead to weakness and instability.
- Build up the intensity of your exercise gradually.5
If you have knee pain that is severe or does not improve after a day or two, it is very important to see a doctor for expert evaluation of the injury. Untreated injuries can lead to chronic pain or deterioration and reduced function of the knee joint. When in doubt, always seek medical attention for knee injuries.6,7
- National Center for Health Statistics 2012 Data Release, BMUS table. bmus.latticegroup.com/docs/T6A.1.1.2.pdf (Accessed 1/21/2019)
- Gordon MD, Steiner ME. Anterior cruciate ligament injuries. Orthopaedic Knowledge Update Sports Medicine III, Garrick JG (Ed), American Academy of Orthopaedic Surgeons, Rosemont 2004. p.169
- Glaviano, et. al., Demographic and Epidemiological Trends in Patellofemoral Pain Int J Sports Phys Ther. 2015 Jun; 10(3): 281-290. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4458915/ (Accessed 1/22/2019)
- ShareCare. "Why is the knee joint so prone to injury?" Sharecare.com. sharecare.com/health/bone-joint-injuries/how-do-knee-joints-work (Accessed 1/22/2019)
- Everyday Health. "9 Ways to Avoid Knee Pain and Injuries." Everydayhealth.com. https://www.everydayhealth.com/knee-pain/how-to-avoid-knee-injuries.aspx (Accessed 1/22/2019)
- American Academy of Orthopaedic Surgeons. "Common Knee Injuries." Orthoinfo.aaos.org. https://orthoinfo.aaos.org/en/diseases--conditions/common-knee-injuries (Accessed 1/11/2019)
- Medline Plus. "Knee Injuries and Disorders". Medlineplus.gov. https://medlineplus.gov/kneeinjuriesanddisorders.html (Accessed 1/11/2019)
The information in this article is for informational and educational purposes and is not meant as medical advice. Every patient's case is unique and each patient should follow his or her doctor's specific instructions. Please discuss nutrition, medication and treatment options with your doctor to make sure you are getting the proper care for your particular situation.