Q.Given below are two statements labelled Assertion (A) and Reason (R). Assertion (A): In a normal standing posture, both knees touch each other, while there is a gap of 3-4 inches between the ankles. Reason (R): It is due to Genu Valgum and it can develop due to an injury or infection in the knee or leg, rickets, severe lack of vitamin D and calcium, obesity, or arthritis in the knee. In the context of the above two statements, which one of the following option is correct? (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A). (B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A). (C) Assertion (A) is true, but Reason (R) is false. (D) Assertion (A) is false, but Reason (R) is true.

Knock Knee Deformity

Knock knee, medically called genu valgum, is a leg alignment where the knees turn inward and touch or knock together in a standing posture, while a gap of roughly 3–4 inches remains between the ankles — the legs form a rough letter X from hip to foot, the mirror opposite of bow legs, which form an O shape.

What Is Happening in the Leg

Normally the thigh bone (femur) and shin bone (tibia) meet at a slight, controlled angle at the knee. In knock knee, the femur slants inward more than it should, pulling the knee toward the body's midline, while the lower leg angles back outward to reach the ground — leaving the ankles apart even when the knees are pressed together.

Who Gets It, and Why It Matters

Mild knock knee is common and normal in young children as part of typical growth, and it usually self-corrects by around age 7–8, though it can persist into adolescence in some cases. When it does not resolve, the uneven angle changes how weight passes through the knee joint — the outer (lateral) side gets compressed and the inner (medial) side gets stretched, which over time can cause pain, accelerate wear on the joint's cartilage, make walking or climbing stairs uncomfortable, and produce an awkward, compensating gait.

Causes

Besides the normal growth phase in early childhood, knock knee can result from injury or infection near the growth plate, rickets, a deficiency of vitamin D or calcium, obesity (which places extra load on developing bones), and arthritis that erodes the joint surface unevenly.

Correctives

The correctives prescribed for knock knee combine simple physical activity with specific therapeutic postures:

• Horse riding, which naturally works the inner thigh muscles against an outward-pulling position …