If your knees touch when you stand but your ankles stay apart, you might have a condition called knock knees. This means your legs angle inward. It’s the opposite of bowlegs, where the knees bend outward. Doctors call knock knees “genu valgum.” For some people, especially those living with obesity, this condition can lead to joint pain or other problems because of added pressure on the knee joints.

Although obesity is one of the causes of knock knees, there are others as well. Learn more about how obesity and knock knees are connected, other potential causes, and how to manage the condition.

What Causes Knock Knees?

In children, knock knees affect girls slightly more often than boys, according to Boston Children’s Hospital. Adults with obesity have a higher risk of knock knees, and the journal Acta Medica notes that this risk is similar in both men and women. Knock knees affect normal walking patterns and cause people to rotate their feet outward.

Children and Babies With Knock Knees

Knock knees are common in toddlers and young children. Kids may angle their knees inward to help with balance. Less often, the cause is a genetic condition or a bone disease. Knock knees are more likely to be a concern if they develop before age 2 or after age 7.

Adults With Knock Knees

In adults, knock knees may result from an injury, a bone infection, or a noncancerous bone tumor. Kidney and metabolic disorders can also play a role, sometimes related to obesity.

Children who don’t have enough vitamin D are prone to a bone disease called rickets. Rickets can cause knock knees and bowlegs. When adults have severely low vitamin D, they can develop a similar problem known as osteomalacia (soft bones). This is a different condition from osteoporosis.

Knock knees don’t always cause other symptoms, but they can lead to pain in the knees or ankles over time. If the condition isn’t treated, knock knees can cause complications like joint damage, osteoarthritis, bone fractures, or problems with the ankle joints.

How Does Obesity Affect the Knee Joint?

Obesity puts more pressure on the knees, which increases the risk of pain and joint problems. For some people, knee issues that start in childhood continue into adulthood.

Up to 71 percent of kids with knock knees have obesity. Children with a higher body mass index (BMI) are also at a greater risk of developing osteoarthritis later in life.

Obesity can change how someone walks, which may make it look like they have knock knees — even if their joints are otherwise healthy. Extra body weight from obesity puts pressure on the knees and can push them out of normal alignment. Over time, this added strain can cause lasting damage, like osteoarthritis. Joint damage from obesity isn’t limited to the knees — the ankles and hips can also be affected.

Researchers have also found strong links between vitamin D deficiency and obesity, but they’re not sure exactly why this connection exists. Low vitamin D in adults doesn’t necessarily cause physical changes in the bone tissue. However, it could raise inflammation levels throughout the body. Other knee problems, including arthritis, tendinitis, and bursitis, are also caused by inflammation.

Living With Obesity and Knock Knees

If you have pain or notice changes in the way you walk, be sure to speak with your doctor. Sometimes, family or friends may notice changes before you do. Your healthcare provider can examine your legs, order tests, and discuss treatment options.

Treatment for Knee Problems

A physical therapist can suggest exercises or other changes to strengthen and support the areas surrounding your knees. They can also teach you ways to avoid strain and injuries. In some cases, knee surgery may be recommended to correct severe knock knees.

Knee Surgery

Two types of surgeries can be used to fix knock knees in adults. The first is called a distal femoral osteotomy (DFO). During this procedure, the surgeon cuts just above the knee into the femur. Then, they reshape and realign the bones. Everything is stabilized with screws and a strong plate. Most people need to stay in the hospital for two nights to recover, followed by several weeks of physical therapy.

Another procedure, called a tibia osteotomy, is better for more extensive knee deformities. It may be combined with DFO to treat a larger area of the leg. The recovery time is the same for both procedures.

Weight Loss and Exercise Considerations

Losing weight can take a lot of pressure off your knees each day. For every additional pound of weight on your body, 5 extra pounds are put on your knees. Ask your healthcare provider for help with weight loss. There are a few different options that can help you reach your goals, even if you’ve struggled to lose weight in the past.

Exercise is important for weight loss and overall health, but it can be tricky with knee problems. High-impact exercise can do more joint damage. Instead, talk to your doctor about exercises that don’t put additional strain on your joints, like swimming, water aerobics, or cycling. Well-cushioned shoes or specialized shoe inserts (orthotics) can also help.

Home Care

If you’re experiencing knee pain, there are some things you can do at home for temporary relief. Start by resting your knee and avoid putting weight on it. To reduce swelling, apply an ice pack and keep your knees raised. Over-the-counter pain medication and supportive bandages are also helpful, but you should discuss using these with your doctor first.

Members of MyObesityTeam have shared their self-care tips for knee pain. “The thing that held me back was pain in both my feet, making it hard to walk. Arthritis left both knees hurting. A friend told me to buy Penetrex to rub on the areas that hurt. I also bought turmeric root to help with inflammation. Today, minimal pain,” shared one member.

It’s important to treat the cause of knee problems, rather than just trying to manage the symptoms. Knock knees and other knee problems can be a sign that obesity is taking a toll on your health. Finding support and treatment that works can help improve your situation so you can live life to the fullest.

Talk With Others Who Understand

On MyObesityTeam, the social network for people with obesity and their loved ones, more than 57,000 members come together to ask questions, give advice, and share their stories with others who understand life with obesity.

Do you have symptoms of knock knees or osteoarthritis? If so, how do knee problems affect your daily life? Share in the comments below or on your Activities page.