Q.Deformity of the legs is known as
Concept understanding — Knock Knee Deformity
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
- Holding a pillow between the knees while standing erect, to retrain the legs toward a straighter alignment
- The yoga postures Padmasana and Gomukhasana
- Seated or lying leg raises to strengthen the muscles supporting proper knee alignment
- Walking callipers, used specifically before puberty while the bones are still developing
- Weight loss, where obesity is a contributing factor
Knock knee is not merely a cosmetic concern — left unaddressed, the uneven joint loading it causes can accelerate arthritis and produce chronic knee pain later in life. Because a mild version is genuinely normal in early childhood, the corrective approach differs by age: pre-puberty, walking callipers and postural correctives are the standard first response; a case that persists or is severe enough to affect gait or cause pain needs assessment beyond self-correction.
Among the options given, only Knock knees is a leg deformity — the other three all affect the spine/back.
Why the other options are wrong
- (a) Scoliosis: sideways curvature of the spine.
- (b) Lordosis: exaggerated inward curve of the lower back.
- (d) Kyphosis: exaggerated forward curve of the upper back.
The correct option is (c) Knock knees.
Knock knees (Genu valgum) is a leg/knee deformity; Scoliosis, Lordosis and Kyphosis are all spinal deformities, not leg deformities.
The textbook groups Knock Knees, Flat Foot and Bow Legs as leg-related deformities (sections 2.2.2, 2.2.3, 2.2.8), separate from the spinal deformities Round Shoulders, Kyphosis, Lordosis and Scoliosis (sections 2.2.4-2.2.7). Knock Knees specifically is a knee misalignment where both knees touch in normal standing, with a 3-4 inch gap remaining between the ankles.
The correct option is (c) Knock knees.
- CBSE 2024Set 75/RQPS/41 markMCQQ.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.
›Reveal solutionSolution
The knees-touching, ankles-apart posture is the classic presentation of Genu Valgum (knock knees), and the Reason correctly names both the condition and its causes. Both statements are true and the Reason explains the Assertion, so the answer is (A).
The Assertion. It states that in a normal standing posture the two knees touch each other while there is a gap of 3-4 inches between the ankles. This is precisely how Genu Valgum (knock knees) looks: the knees angle inward, so on standing normally they knock together while the ankles stay a few inches apart. The Assertion is therefore a true description of this deformity.
The Reason. It states that the posture is due to Genu Valgum and can develop from an injury or infection in the knee or leg, rickets, a severe lack of vitamin D and calcium, obesity, or arthritis of the knee. These are all accepted causes of knock knees, so the Reason is also true.
Linking the two. The Reason does more than sit beside the Assertion — it accounts for it. The inward knee alignment named in the Reason is exactly what produces the knees-together, ankles-apart posture described in the Assertion. Because the Reason identifies the condition and the causes that create that posture, it is the correct explanation of the Assertion.
✓Final answer(A) — Both Assertion and Reason are true, and the Reason is the correct explanation of the Assertion: the inward-angled knees of Genu Valgum are what make the knees touch while the ankles stay 3-4 inches apart.
- CBSE 2023Set 75/EF1GH/41 markMCQQ.Match the following: List - I I. Knock Knee / Genu Valgum II. Kyphosis III. Lordosis IV. Bow legs List - II 1. Increase exaggeration of backward curve 2. Wide gap between the knees when standing with feet together 3. Knees touch each other in normal standing position 4. Inward curvature of the spine Choose the correct option from the following:(a) I-3, II-1, III-4, IV-2(b) I-1, II-3, III-4, IV-2(c) I-4, II-2, III-1, IV-3(d) I-2, II-3, III-4, IV-1
›Reveal solutionSolution
Knock Knee = knees touch (3); Kyphosis = exaggerated backward curve (1); Lordosis = inward spinal curvature (4); Bow legs = gap between knees (2) — option (a).
These four postural deformities are distinguished by which direction the body deviates from ideal alignment. Knock Knee (Genu Valgum) is defined by the knees touching each other while there remains a gap between the ankles when standing normally — matching description 3. Kyphosis is an excessive outward/backward curvature of the upper (thoracic) spine, producing a hunched appearance — matching description 1 ("increase in exaggeration of backward curve"). Lordosis is the opposite: an excessive inward curvature of the lower (lumbar) spine — matching description 4. Bow legs (Genu Varum) is the mirror image of knock knee: the knees stay apart while the ankles touch, producing the "wide gap between the knees" described in item 2.
✓Final answer(a) I-3, II-1, III-4, IV-2.
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