Q.Define Knock Knee and Bow Legs. Explain their causes and the corrective measures for each.

Knock Knee (Genu Valgum) is a condition where the knees touch or overlap when standing with the feet apart. The lower legs angle outward, creating a gap between the ankles. This misalignment shifts the body's weight line to the inside of the knee, straining the medial ligaments.

Bow Legs (Genu Varum) is the opposite deformity. The knees remain apart even when the ankles are together, causing the legs to curve outward like a bow. The weight line falls to the outside of the knee, stressing the lateral structures.

Causes of Knock Knee:

• Nutritional: Severe deficiency of Vitamin D and calcium (rickets) softens the leg bones, causing them to bend under body weight.
• Postural: Habitually standing with the feet turned outward and the knees forced together.
• Structural: Loose medial knee ligaments or weak quadriceps muscles.

Causes of Bow Legs:

• Nutritional: Rickets is the most common cause in children, leading to soft, bowed tibias and femurs.
• Postural: Premature walking before the bones are strong enough, or habitually standing with the feet turned inward.
• Structural: Tight lateral knee ligaments or weak hamstring muscles.

Corrective Measures for Knock Knee:

• Exercises: Practice sitting in a "diamond" position (soles of feet together, knees pressed toward the floor). Perform straight-leg raises while lying on the side to strengthen the outer thigh (vastus lateralis). Walking on the outer edges of the feet is a specific corrective gait.
• Postural: Avoid standing with the knees locked together. Use a rolled towel between the ankles while sleeping to maintain alignment.
• Medical: In severe cases, a doctor may prescribe a night splint or, rarely, surgical correction.

Corrective Measures for Bow Legs: …

Understanding Postural Deformities of the Legs

Postural deformities are deviations from the normal alignment of body segments. When we talk about the legs, the ideal alignment is a straight line from the hip through the knee to the ankle. Two common deviations from this line are knock knee and bow legs. These aren't just cosmetic concerns — they affect gait, joint health, and can lead to pain in the knees, hips, and lower back over time.

The key to understanding both conditions lies in the distribution of body weight through the knee joint. In a normal leg, weight passes evenly through the medial (inner) and lateral (outer) compartments of the knee. In knock knee, the weight shifts to the outer compartment; in bow legs, it shifts to the inner compartment. This imbalance stresses the ligaments and cartilage, particularly the menisci.

Knock Knee (Genu Valgum)

Definition: Knock knee is a condition where the knees touch each other while the ankles remain apart when standing with feet together. The lower legs angle outward from the knee, giving the legs an "X" shape.

Causes

• Rickets: Vitamin D deficiency leads to soft, weak bones that bend under body weight. This is the most common cause in children.
• Flat feet: When the arches collapse, the ankles roll inward, which can force the knees together over time.
• Muscle imbalance: Weakness in the hip abductors (gluteus medius and minimus) and tightness in the hip adductors (inner thigh muscles) pull the knees inward.
• Obesity: Excess body weight increases the load on the knees, worsening any tendency toward valgus alignment.
• Poor posture: Habitually standing with knees locked and weight on the inner edges of the feet.
• Arthritis: In adults, osteoarthritis can erode the outer knee cartilage, causing a gradual knock knee deformity.

Corrective Measures

1. Stretching exercises — target the tight structures on the inner side of the leg:

• Adductor stretch: Sit on the floor with soles of feet together and knees dropped toward the floor. Hold for 20–30 seconds.
• Inner thigh stretch: Stand with feet wide apart, shift weight to one side, keeping the other leg straight.

2. Strengthening exercises — target the weak muscles on the outer side:

• Hip abduction: Lie on your side and lift the top leg straight up, keeping the knee extended. Do 3 sets of 10–15 reps per side.
• Ankle eversion: Sit with legs extended, loop a resistance band around the outer edge of one foot, and turn the foot outward against resistance.

3. Walking with a book between the ankles: This simple drill forces the ankles to stay together, training the brain to maintain proper alignment.

4. Footwear correction: Use arch supports or orthotics if flat feet are contributing to the problem.

5. Sleeping posture: Avoid sleeping with knees pressed together; place a small pillow between the knees when lying on the side.

Bow Legs (Genu Varum)

Definition: Bow legs is the opposite condition — the ankles touch while the knees remain apart when standing with feet together. The lower legs angle inward, giving the legs an "O" shape.

Causes

• Rickets: Again, vitamin D deficiency is the primary cause. The soft tibia and femur bow outward under body weight.
• Blount's disease: A growth disorder of the tibia that causes the upper shinbone to grow abnormally, leading to progressive bowing. This is more common in children who start walking early and are overweight.
• Improper walking posture: Walking with feet turned excessively inward (pigeon-toed) can contribute.
• Ligament laxity: Loose ligaments on the inner side of the knee allow the joint to open up.
• Arthritis: Osteoarthritis that erodes the inner knee cartilage can produce bow legs in adults.
• Congenital factors: Some children are born with mild bowing that resolves naturally.

Corrective Measures

1. Stretching exercises — target the tight structures on the outer side of the leg:

• Hip adductor stretch: Sit with legs spread wide apart, lean forward from the hips, keeping the back straight.
• IT band stretch: Cross one leg behind the other, lean to the opposite side, and hold.

2. Strengthening exercises — target the weak muscles on the inner side: …