Genu valgum, commonly known as knock knees, describes a condition where the knees angle inward, causing them to touch or “knock” against each other when a person stands with their feet apart. This inward angling of the knees can lead to long-term issues with joint function and chronic pain. Individuals frequently seek non-surgical methods, particularly exercise, to address this misalignment. This article examines the structural realities of knock knees in adulthood and clarifies the role that targeted exercise plays in managing this condition.
Understanding Adult Genu Valgum
Genu valgum is characterized by a valgus deformity, meaning the lower leg (tibia) is angled away from the midline of the body relative to the thigh bone (femur). The condition is often developmental, with many children exhibiting a temporary form that naturally resolves by age seven. When the condition persists into adulthood, it represents a fixed structural deformation involving the femur, the tibia, or both bones that form the knee joint.
This adult misalignment can stem from developmental issues that never fully corrected, or it can be acquired later in life. Acquired genu valgum often results from underlying medical conditions such as arthritis, especially osteoarthritis, or from poorly healed fractures. The resulting mechanical axis deviation places disproportionate stress on the lateral (outer) compartment of the knee, which can accelerate degenerative changes over time.
Exercise and Bone Alignment in Adulthood
The central question for many adults is whether exercise can physically change the angle of the bones to correct the alignment. The answer is that exercise cannot alter the fixed bony structure of the legs in a skeletally mature adult. This limitation is due to the closure of the growth plates (physes), which occurs at the end of adolescence.
Once the growth plates fuse, the bones lose their capacity for growth-based realignment. Therefore, the structural deviation that defines genu valgum remains a permanent feature of the skeleton. Exercises suggested for adult knock knees are not intended to physically move the femur or tibia, but rather to improve the body’s functional compensation for the misalignment.
The Functional Benefits of Targeted Exercise
While exercise cannot physically realign the bones, it serves a function by improving the dynamics of the knee joint and the entire kinetic chain. The primary goal of a targeted exercise program is to strengthen the muscle groups that stabilize the knee and counteract the inward rotation of the femur. This functional improvement helps to manage symptoms like pain and slow the progression of joint degeneration.
A major focus is strengthening the external rotators of the hip, particularly the gluteus medius and gluteus maximus muscles. When these muscles are weak, the femur tends to rotate internally, which exaggerates the inward angle of the knee and increases stress on the joint. By strengthening these hip stabilizers, patients gain better control over the alignment of the leg during walking and standing.
Targeted resistance exercises, sometimes utilizing elastic bands, enhance muscle electrical activity and improve overall knee stability. These exercises are designed to improve neuromuscular function and balance, which helps to optimize the gait cycle. Improving the strength of the hip abductors and core stabilizers helps create a more efficient movement pattern, reducing the excessive pressure placed on the medial compartment of the knee joint. Specific stretches are also incorporated to address tightness in opposing muscle groups.
When Medical Intervention is Necessary
For some adults, particularly when the structural deviation is severe or when conservative measures like exercise fail to control symptoms, medical intervention becomes necessary. Severe genu valgum can lead to chronic, debilitating pain and contribute to the early onset of degenerative joint disease. In these cases, the fixed nature of the bony deformity requires a structural solution.
Non-surgical medical options include custom-made foot orthotics, which are inserts placed in the shoes to help redistribute the load and correct a faulty gait pattern. These devices work by subtly altering the biomechanics of the lower limb to reduce the abnormal stresses on the knee joint. Bracing may also be used to provide external support and stability to the knee during activity.
For cases that cause significant functional limitation or rapid joint deterioration, surgical procedures are considered. The most common surgical approach for a skeletally mature adult is an osteotomy, which involves surgically cutting and physically realigning the bone, typically the femur or tibia. The goal of an osteotomy is to shift the mechanical axis of the limb to an area of the knee joint that is less damaged, thereby evening out the weight distribution and slowing the progression of arthritis.
In older adults with advanced joint destruction, total or partial knee replacement surgery may be the most appropriate treatment option. This procedure replaces the damaged joint surfaces with an artificial implant that is correctly aligned.