Knock knees can often be improved through targeted strengthening exercises, weight management, and in some cases medical treatment, but the right approach depends entirely on your age and the underlying cause. In children under seven, knock knees are almost always a normal phase of growth that resolves on its own. In older children, teens, and adults, correction may require physical therapy, lifestyle changes, or surgery depending on severity.
When Knock Knees Are Normal in Children
Children’s legs go through predictable alignment changes as they grow. Knock knees first appear around age two and peak between ages three and four, when a child’s legs can angle inward by as much as 8 to 10 degrees. This is completely normal. Over the next few years, the angle gradually decreases, settling into a stable adult alignment of 5 to 7 degrees by age seven. Most children younger than six who are evaluated for knock knees actually have this normal developmental pattern and need no treatment at all.
The concern starts when knock knees persist or worsen after age seven, when they affect only one leg, or when the inward angle is extreme. A simple clinical measurement called intermalleolar distance helps gauge severity: with the inner sides of the knees touching, the gap between the inner anklebones is measured. A distance greater than 8 centimeters is generally considered abnormal and worth investigating further.
What Causes Knock Knees in Adults
When knock knees develop or persist past childhood, there’s usually an identifiable reason. The most common include:
- Vitamin D deficiency and osteomalacia: Softened bones from poor mineralization can gradually bow under body weight. This is more common in people with darker skin, obesity, limited sun exposure, celiac disease, kidney disease, or a history of gastric bypass surgery. Certain medications, including some anti-seizure drugs, can also deplete vitamin D levels enough to weaken bone.
- Obesity: Excess weight dramatically increases the forces traveling through the knee. Research shows that people with class 2 obesity (BMI 35 to 41) experience roughly 2.5 times more additional compressive load on the knee than their extra body weight alone would suggest. That amplified stress can worsen alignment over time.
- Injury or infection: A fracture near the knee’s growth plate during childhood, or a bone infection, can disrupt growth on one side and create a lasting angular deformity.
- Genetic and metabolic conditions: Conditions like rickets, kidney disorders that waste phosphate, and certain skeletal dysplasias can all produce knock knees that won’t resolve without treating the root cause.
If your knock knees appeared in adulthood or have been getting worse, identifying and addressing the underlying cause is the first and most important step. All the exercise in the world won’t straighten bones that are softening from a vitamin D deficiency.
Strengthening Exercises That Help
Knock knees often involve weak hip and thigh muscles that fail to keep the knee tracking properly. When the muscles on the outside of your hip (the gluteus medius and the tensor fascia) are weak relative to the inner thigh, the knees drift inward during walking, squatting, and stair climbing. A targeted exercise program can improve this muscular imbalance and reduce the functional component of knock knees, even if it can’t change the underlying bone angle.
The key muscle groups to focus on are the gluteus medius and gluteus maximus in the buttocks, the hamstrings at the back of the thigh, and the outer hip abductors. Exercises that target these areas include:
- Side-lying leg raises: Lying on your side with legs straight, lift the top leg to about 45 degrees and lower slowly. This directly works the hip abductors that pull the knee outward.
- Clamshells: Lying on your side with knees bent, keep your feet together and rotate the top knee open like a clamshell. This isolates the gluteus medius.
- Single-leg squats or step-downs: Standing on one leg on a step, slowly lower the other foot toward the ground. Focus on keeping the standing knee aligned over your second toe rather than collapsing inward.
- Standing hip rotation exercises: Internal hip rotation drills work the medial hamstrings, which help stabilize knee alignment from behind.
Aim for two to three sessions per week, starting with 8 to 10 repetitions per exercise and building from there. Stretching the outer hip, particularly the iliotibial band and piriformis, complements the strengthening work by reducing tightness that can pull the leg into poor alignment. Consistency over months matters far more than intensity in any single session. These exercises won’t reshape bone, but they can meaningfully change how your knee moves and reduce pain and strain on the joint.
Does Weight Loss Make a Difference?
Yes, and more than you might expect. Research on knee joint loading shows a clear dose-response relationship between body weight and the compressive forces grinding through the knee. The mechanical disadvantage of extra weight is amplified at the knee because of how forces multiply across the joint during walking. Each pound of body weight translates to roughly two and a half pounds of additional compressive force at the knee. Studies confirm that reducing body mass directly reduces these compressive loads, which can slow cartilage damage and ease symptoms in people with knock knees.
Weight loss won’t change the angle of your bones, but it meaningfully reduces the total force your misaligned knees have to handle every step of the day. For people who are overweight or obese with knock knees, losing weight is one of the most effective non-surgical interventions available.
Do Orthotics or Braces Work?
The evidence on shoe inserts and braces for knock knees is mixed at best. Lateral wedge insoles, which are thicker on the outside edge to shift weight distribution, have been studied primarily for the opposite problem (bow legs), and the research that does exist for knock knees is inconclusive. One long-term study found that wearing wedge insoles for 12 months provided no symptomatic or structural benefits compared to flat insoles. Some researchers have reported that orthotics may slow cartilage breakdown, but other studies directly contradict this.
Braces can help manage symptoms by altering how load distributes across the knee during activity, but they don’t permanently change bone alignment. They’re best thought of as a tool for pain management rather than a correction strategy.
Why Correction Matters Long-Term
Untreated knock knees don’t just cause cosmetic concerns. They shift mechanical stress to the outer (lateral) compartment of the knee, accelerating cartilage wear in that area. A large study combining data from two major osteoarthritis research projects found that people with a valgus angle greater than 3 degrees were roughly 2.5 to 3 times more likely to develop lateral knee osteoarthritis than those with neutral alignment. The same study found that valgus alignment was associated with nearly six times the odds of cartilage damage visible on MRI, even in knees that appeared normal on standard X-rays. Addressing knock knees early, whether through exercise, weight loss, or surgery, is partly about protecting your knee cartilage for the decades ahead.
Guided Growth Surgery for Children
For children whose knock knees haven’t resolved by age seven or eight, a procedure called guided growth (hemiepiphysiodesis) can correct alignment while the bones are still growing. A small metal plate is placed on the inner side of the growth plate near the knee, which temporarily slows growth on that side while the outer side catches up. Once the leg straightens, the plate is removed and normal growth resumes.
The procedure is minimally invasive compared to older techniques that required cutting and repositioning bone. For children with idiopathic knock knees (meaning no underlying disease), guided growth has a success rate of about 89.5%. The child needs to have open growth plates, which is confirmed by X-ray before surgery. Results are less predictable when knock knees stem from conditions like skeletal dysplasias, prior infections, or growth plate injuries from fractures, with failure rates climbing significantly in those groups.
Corrective Osteotomy for Adults
Adults whose growth plates have closed can’t benefit from guided growth, so correcting significant knock knees surgically requires an osteotomy. In this procedure, a wedge of bone is either removed or added near the knee to realign the leg. It’s typically considered for younger adults who aren’t good candidates for knee replacement but have enough misalignment to cause pain or accelerating cartilage damage.
Recovery from osteotomy is substantial. You’ll typically spend two to three days in the hospital, start physical therapy the day after surgery, and use crutches with partial weight bearing for the first six weeks. The transition to a single crutch or cane happens around six weeks, with most people returning to work part-time at two to three months. Full activity, excluding high-impact sports, is usually possible at six months when the bone cuts have healed. Full recovery, meaning the point where your leg feels truly normal again, typically takes 9 to 12 months. Newer techniques using 3D-printed cutting guides customized to your anatomy are improving surgical precision and shortening operating times.