Knee valgus, commonly known as knock-knees, is a biomechanical issue where the knees angle inward. This misalignment causes the knees to track toward the midline of the body, often touching while the ankles remain separated. An excessive inward angle increases the stress placed on the knee joint and surrounding structures. This altered load distribution can increase the risk of knee pain, patellofemoral issues, and the premature development of osteoarthritis. Correcting this common movement pattern through targeted exercise is a proactive step toward maintaining long-term knee health and function.
Understanding the Biomechanical Causes of Valgus
The inward collapse of the knee during movement is often a symptom of underlying imbalances throughout the entire kinetic chain, connecting the foot, ankle, knee, and hip. The primary driver of dynamic valgus is typically a lack of control and strength in the muscles surrounding the hip. Specifically, weakness in the hip abductors and external rotators, such as the Gluteus Medius and Gluteus Maximus, prevents the femur from being stabilized.
When these stabilizing muscles are weak, the thigh tends to adduct and internally rotate when the foot is planted, forcing the knee inward. This pattern is often exacerbated by tightness in opposing muscle groups. Overly tight hip flexors or hip adductors can encourage the thigh’s internal rotation, further contributing to the valgus position.
The foot and ankle also play a significant role, as excessive foot pronation (flattening of the arch) causes the lower leg to rotate internally. This inward rotation creates a ripple effect that contributes to the knee’s collapse. Therefore, correction requires a comprehensive approach that addresses both strength deficits in the hips and mobility restrictions.
Targeted Strengthening and Mobility Exercises
A corrective exercise program focuses on two main components: lengthening tight structures and strengthening weak, stabilizing muscles. Gluteal strengthening is the cornerstone of this approach, specifically targeting the muscles responsible for abducting and externally rotating the hip. The Banded Clamshell is an excellent starting point, performed by lying on your side with a resistance band looped around your knees, then lifting the top knee while keeping the feet together.
For functional strength, Banded Side Steps are highly effective, performed by placing a resistance band around the ankles or thighs and stepping laterally while maintaining a slight squat posture. This exercise trains the hip abductors to resist the inward pull of the knee during weight-bearing movement. The Single-Leg Deadlift (SLDL) progresses this stability work by challenging the hip to maintain neutral alignment during a single-leg hip-hinge motion.
To address common mobility restrictions, the Half-Kneeling Hip Flexor Stretch is performed by kneeling on one knee, then gently pushing the hips forward while squeezing the glute of the kneeling leg. This movement helps to lengthen the often-shortened hip flexors, which can reduce the pelvic tilt contributing to knee valgus. Combining these strengthening and mobility exercises helps to reprogram the neuromuscular system for lower body stability.
Supportive Aids and Movement Pattern Correction
Correcting knee valgus includes conscious adjustments to everyday movement and the use of external aids. Footwear and orthotics are important considerations, especially when foot overpronation is a contributing factor. Orthotic insoles, whether over-the-counter or custom-made, are designed to support the arch and help control excessive pronation, which reduces the internal rotation of the lower leg.
For individuals with significant foot involvement, orthotics with medial posting (thicker on the inner edge) can help realign the foot and ankle, influencing the mechanics of the knee joint above. Orthotics are generally used in conjunction with a strength and mobility program, not as a replacement.
The most powerful tool for long-term correction is conscious movement pattern training. This involves focusing on maintaining proper knee alignment during functional activities like squatting, climbing stairs, and walking. The key cue is to ensure the knee tracks directly over the second toe, preventing inward collapse. During a squat, using a resistance band looped just above the knees provides a constant sensory cue to push the knees outward, retraining the motor pattern.
Recognizing When Professional Intervention Is Necessary
Many cases of knee valgus are dynamic, resulting from muscle imbalance and poor movement patterns that can be corrected with exercise. However, a distinction must be made between dynamic valgus and structural valgus (genu valgum), which is caused by a fixed anatomical deviation, such as a malformation in the bones of the femur or tibia. Structural valgus is less responsive to exercise alone and may require medical intervention.
If a dedicated strengthening and mobility program fails to produce noticeable improvement after several weeks or months, or if the valgus is accompanied by persistent, severe pain, professional consultation is necessary. A Physical Therapist (PT) can perform a detailed gait analysis and a personalized assessment to confirm the root cause and establish a specialized treatment plan. Consultation with an orthopedic specialist is warranted if the pain is acute, if there is a noticeable and fixed deformity, or if the knee feels unstable.