What should you know about one bow leg?

Bow legs, also called genu varum, describe an outward curve that may be noticed when the ankles are close together and the knees remain apart. One-sided bowing can be a difference in bone alignment, a result of an earlier injury, or a sign that the leg is developing unevenly. In a child, growth stage matters; in an adult, new change or pain deserves closer review.

Alignment can affect how weight passes through the knee and ankle. Watch for limp, fatigue, stiffness, reduced activity, unequal shoe wear or difficulty keeping up with usual tasks.

Arrange an orthopaedic review if the curve is new, clearly increasing, associated with pain, or affecting walking. Bring information about when it was first noticed, prior fractures or surgery, family patterns and any change in height or activity. A clinician may compare both legs and assess hips, knees, ankles and walking pattern.

For a child, do not use braces, supplements or exercises without guidance. Paediatric physiotherapy may support movement and function when recommended, but exercises do not necessarily change the shape of a growing bone.

Seek prompt assessment for sudden deformity after an injury, inability to bear weight, severe pain, marked swelling, fever, a hot joint, new weakness or numbness. A gradual painless difference can be booked for routine review, but it should still be checked if it progresses.

Ask what is causing the asymmetry, whether an X-ray or other assessment is needed, and whether the alignment is affecting the knee or ankle. Discuss observation, physiotherapy and, for selected cases, whether an osteotomy is appropriate and what recovery would involve.