Knock Knees

Quick answer: Knock knees (genu valgum) is when the knees angle inward toward each other while the ankles stay apart. In young children it’s a normal stage of growth that usually straightens out on its own. In adults it most often reflects how the hips, legs and feet work together, with the inward pull usually starting at the hip rather than the knee itself.

Maybe you’ve noticed your knees touch when you stand with your feet a little apart, or they drift inward when you squat, run or take the stairs. Maybe you’re a parent wondering whether your child’s legs are developing normally. Either way, the first step is understanding which kind of knock knees you’re looking at.

What Are Knock Knees?

With knock knees, the thighs angle inward so the knees come close together or touch, while the lower legs angle out and the ankles stay apart. The medical term is genu valgum, and you’ll also hear “valgus knees.” It can be static, visible when you simply stand, or dynamic, when the knees cave inward only as you move. In adults, the dynamic kind is far more common.

Knock knees are the opposite of bow legs (genu varum), where the knees bow apart and the ankles come together.

Do I Have Knock Knees? A Simple Self-Test

1. Standing test. Stand barefoot in front of a full-length mirror and bring your knees gently together, without forcing. Is there a gap between your ankles? A small gap is common; a larger one suggests knock knees.
2. Mini-squat test. Stand with your feet hip-width apart and slowly bend your knees into a shallow squat. Watch your kneecaps. Do they stay over your second toe, or drift inward toward each other?
3. Single-leg test. Stand on one leg and bend the knee slightly. Does that knee cave inward, or your hip drop on the other side? Compare both sides.

If only the mini-squat and single-leg tests show it, your knock knees are probably dynamic, which is the kind most influenced by muscle control and movement habits.

Are Knock Knees Normal in Children?

Usually, yes. Most babies are bowlegged, their legs straighten as they learn to walk, and then many children become knock-kneed. According to KidsHealth from Nemours, knock knees are a normal part of development between about ages 2 and 4 and usually improve by age 7 or 8. Special shoes and braces aren’t needed for this normal pattern.

Talk to your child’s pediatrician if the knock knees are much worse on one side, appear or get worse after about age 6, are severe, or come with pain, limping, or short stature for their age.

What Causes Knock Knees in Adults?

• Hip control. When the muscles on the outside and back of the hips (the glutes) aren’t steering the thigh well, the thigh rolls inward and the knee follows. This is the most common pattern we see.
• Feet and ankles. Arches that flatten and roll in (overpronation) let the shin rotate inward, pulling the knee with it.
• Pelvis and trunk position. A forward-tipped pelvis (anterior pelvic tilt) or a lateral pelvic tilt changes how the thighs hang and often shows up as one knee caving more than the other.
• Joint changes. Knee osteoarthritis that wears the outer part of the joint can gradually angle the knee inward.
• Childhood or structural causes. Knock knees that didn’t fully straighten in childhood, an old growth plate injury, or bone conditions such as rickets.

Knock Knees When You Move

Knock knees often matter most in motion. When your foot lands and your knee caves inward, the load that should run straight through the knee gets twisted. A keen hiker we worked with came in with pain on the inside of one knee after long hikes. The knee was the place that hurt, but the pattern started above it: the hip wasn’t controlling the thigh as her foot hit the ground, so the knee dropped inward with every step.

What Are the Symptoms of Knock Knees?

Many people with mild knock knees have no symptoms at all. When there are symptoms, people commonly describe:

• Aching on the inside of the knee, or around the kneecap
• Knee discomfort with running, stairs, squats or walking
• Hip or foot discomfort, often on the same side
• Knees brushing together when walking or running
• Feeling less stable landing from a jump or on uneven ground

None of these proves knock knees are the cause. See a doctor if you have knee swelling, locking, giving way, or pain that doesn’t settle.

How Do You Fix Knock Knees?

If you’ve tried to fix your knees by pushing them outward as you move, you’ve probably found it’s hard to remember and feels awkward. That’s because the knee is mostly following orders from above and below. Working on the knee alone rarely changes the pattern.

What tends to help with dynamic knock knees is retraining the hips to steer the thighs, improving how the feet and ankles move, and practicing movements until good knee alignment happens without thinking about it. How much the alignment changes varies from person to person. Structural knock knees, from bone shape or joint changes, won’t change the same way, and severe cases are sometimes treated surgically.

Exercises for Knock Knees

Three starting points. Move slowly, and stop anything that causes pain.

1. Static Wall

Lie on your back with your legs straight up a wall, hip-width apart, and your arms relaxed out to the sides with palms up. Your buttocks should touch or be just off the wall, with the back of your pelvis on the floor. If your lower back lifts, or you can’t straighten your legs, scoot away from the wall until it’s comfortable. Tighten your thighs, point your knees straight toward the ceiling rather than letting them roll in, and pull your feet down toward you so they’re parallel. Hold for 3 to 4 minutes.

2. Gravity Drop

Stand on a step or stair with the balls of your feet on the edge and your heels hanging off, holding a railing or wall for balance. Keep your feet hip-width apart and pointing straight ahead. Let your heels drop below the step until you feel a stretch in your calves, with your hips stacked over your heels and your upper body upright rather than leaning forward. Keep your knees straight and facing forward. Hold for 1 to 3 minutes.

3. Sitting Floor

Sit on the floor with your back upright against a wall and your legs straight out in front of you, hip-width apart. Pull your toes back toward you, tighten your thighs, and keep your kneecaps pointing straight up rather than rolling inward. Rest your hands on your thighs, draw your shoulder blades gently back, and breathe easily. Hold for 1 to 3 minutes.

For more work on the hips and pelvis, see our lateral pelvic tilt exercises.

Choosing Your Next Step

There’s no single right path. It depends on how you like to work:

• You’d like to start on your own. The self-tests and exercises above are a sensible place to begin.
• You’d like someone to find what’s driving it. A free 30-minute consultation includes a postural assessment of how you stand, walk and squat. We have clinics in Newton, Gloucester, Santa Monica, Beverly Grove and Middletown, RI.
• You’re not near a clinic. Virtual posture therapy brings the same assessment approach to you.

Frequently Asked Questions About Knock Knees

Are knock knees normal?

In young children, yes. It’s a normal stage of growth. In adults, a small amount is common and often causes no problems. Lurie Children’s Hospital notes that people with a small amount of knock knees can usually play sports and lead a normal life.

Can knock knees be corrected in adults?

Dynamic knock knees, where the knees cave in during movement, often change with consistent work on hip and foot control. Structural knock knees from bone shape or arthritis won’t change the same way, though better muscle control can still help how the knees handle load. An assessment can help tell which you have.

Do knock knees affect running?

They can. When the knees cave inward as each foot lands, the knee, hip and foot all absorb load at an angle. Many runners with knock knees notice discomfort around the kneecap or the inside of the knee, especially on longer runs.

Do braces or orthotics fix knock knees?

In children with normal developmental knock knees, braces and special shoes aren’t needed. In adults, orthotics can help if flat or rolling-in arches are part of the picture, but they don’t retrain the hips. If a doctor or podiatrist has prescribed them, keep using them unless they advise otherwise.

Do I need surgery to fix knock knees?

Most people don’t. Surgery is usually reserved for severe structural cases or those caused by bone conditions or injury. That decision belongs with an orthopedic surgeon, and posture work can sit alongside it.

This article is general education, not medical advice. If you have knee swelling, locking, giving way, or persistent pain, see a physician or orthopedist first. For children, start with their pediatrician. Posture therapy works alongside medical care, never instead of it.

Related reading: Leg and Knee Alignment: the complete guide.