Knocking Knees: Understanding the Link to Lower Back Pain and Corrective Strategies

Can Knocking Knees Cause Lower Back Pain?

Yes, knocking knees (genu valgum) can significantly contribute to lower back pain by disrupting the kinetic chain, leading to compensatory movements and muscular imbalances throughout the lower body and trunk.

Understanding Genu Valgum (Knocking Knees)

Genu valgum, commonly known as "knocking knees," is a condition where the knees angle inward and touch or nearly touch when a person stands with their feet apart. While some degree of valgus alignment is normal, excessive or persistent genu valgum, especially when dynamic (e.g., during squats, running, or jumping), indicates a biomechanical issue. This inward collapse of the knee joint can stem from various factors, including anatomical structure, developmental issues, or, more commonly in adults and active individuals, acquired muscular imbalances and poor movement patterns.

The Kinetic Chain Connection: From Knees to Back

The human body operates as an integrated kinetic chain, where the movement or dysfunction of one joint can profoundly impact others both above and below it. When the knees collapse inward (valgus collapse), it initiates a cascade of compensations throughout this chain:

• Foot and Ankle: Often, valgus collapse is associated with excessive pronation (flattening) of the foot, where the arch collapses, and the ankle rolls inward. This can be both a cause and an effect of knee valgus.
• Hip: To accommodate the inward knee movement, the femur (thigh bone) typically undergoes excessive internal rotation and adduction (moving towards the midline) at the hip joint. This places undue stress on the hip capsule and surrounding musculature.
• Pelvis and Spine: The internal rotation and adduction of the femurs at the hip can then lead to compensatory movements at the pelvis. This might manifest as an anterior pelvic tilt, excessive pelvic rotation, or altered lumbopelvic rhythm during movement, directly impacting the lumbar spine's alignment and stability.

Muscular Imbalances Associated with Genu Valgum

Dynamic knee valgus is frequently a symptom of specific muscular imbalances, particularly in the hip and thigh region:

• Weakness of the Hip Abductors: The gluteus medius and minimus muscles are crucial for stabilizing the pelvis and preventing the femur from adducting and internally rotating. Weakness here allows the knee to collapse inward.
• Weakness of the Hip External Rotators: Muscles like the gluteus maximus (which also extends the hip) and piriformis are responsible for externally rotating the femur. Inactivity or weakness in these muscles contributes to internal hip rotation and knee valgus.
• Weakness of the Vastus Medialis Obliquus (VMO): This quadriceps muscle helps track the patella (kneecap) and can be less active in individuals with valgus collapse, contributing to patellofemoral pain.
• Overactivity/Tightness of the Hip Adductors: The inner thigh muscles (adductors) can become overactive or tight, pulling the femur inward and exacerbating knee valgus.
• Overactivity/Tightness of the Tensor Fasciae Latae (TFL) and IT Band: The TFL, a hip flexor and abductor, often becomes tight and overactive, contributing to internal hip rotation and pulling on the IT band, which can contribute to lateral knee pain and valgus collapse.

How These Imbalances Lead to Lower Back Pain

The compensatory movements and muscular imbalances stemming from genu valgum directly stress the lower back:

• Altered Pelvic Position and Lumbar Curvature: Weak glutes and tight adductors/hip flexors can lead to an anterior pelvic tilt or excessive pelvic sway. This shifts the natural curve of the lumbar spine (lordosis), increasing compression on the facet joints and discs in the lower back.
• Torsional Stress on the Lumbar Spine: If one hip internally rotates more than the other, or if the hips excessively rotate during gait, the pelvis can twist, creating rotational forces on the lumbar vertebrae. This can lead to muscular strain, disc irritation, or joint pain in the lower back.
• Compromised Core Stability: The deep core muscles (transversus abdominis, multifidus, pelvic floor) are designed to stabilize the spine. When the lower kinetic chain is dysfunctional, the body often struggles to maintain optimal core engagement, leaving the lumbar spine vulnerable to injury and pain.
• Inefficient Movement Patterns: During activities like walking, running, or lifting, the body compensates for the valgus collapse. These inefficient movement patterns place abnormal loads on the lower back over time, leading to cumulative microtrauma and chronic pain.

Identifying Knocking Knees and Associated Pain

You might suspect dynamic knee valgus if:

• Your knees visibly collapse inward during squats, lunges, or when landing from a jump.
• You experience pain around the kneecap (patellofemoral pain), hip pain, or lower back pain.
• The lower back pain is often exacerbated after physical activity, prolonged standing, or walking.
• The pain may be localized to one side of the lower back if the valgus collapse is more pronounced on that side.

A professional assessment by a physical therapist or kinesiologist can accurately diagnose the underlying causes of your knee valgus and its contribution to back pain.

Corrective Strategies and Management

Addressing genu valgum and its associated lower back pain requires a comprehensive approach focused on strengthening, stretching, and neuromuscular re-education:

• Strengthening Key Muscles:
  • Gluteal Muscles: Focus on exercises like clamshells, lateral band walks, glute bridges, hip thrusts, and single-leg Romanian deadlifts (RDLs).
  • Vastus Medialis Obliquus (VMO): Incorporate terminal knee extensions with a focus on VMO activation.
  • Core Stabilizers: Include planks, side planks, bird-dog, and dead bug exercises to improve lumbopelvic stability.
• Stretching and Mobility:
  • Hip Adductors: Perform seated butterfly stretches and standing adductor stretches.
  • Tensor Fasciae Latae (TFL) and IT Band: Utilize foam rolling and specific stretches for these structures.
  • Hip Flexors: Kneeling hip flexor stretches can help address anterior pelvic tilt.
• Neuromuscular Re-education: Actively practice "knees out" cues during squats, lunges, and other lower body movements. Focus on maintaining proper alignment and engaging the correct muscles. This helps retrain the brain to adopt healthier movement patterns.
• Footwear and Orthotics: If excessive foot pronation is a significant contributing factor, consider supportive footwear or custom orthotics to provide better foundational stability.
• Gradual Progression: When starting any new exercise program, gradually increase intensity and volume to allow the body to adapt and prevent further injury.

When to Seek Professional Help

While self-management can be effective, it's crucial to seek professional guidance if:

• Your lower back pain is persistent, severe, or worsening.
• You experience numbness, tingling, or weakness in your legs or feet.
• The pain significantly impacts your daily activities or ability to exercise.
• You are unsure about the correct form or appropriate exercises.

A physical therapist, kinesiologist, or orthopedic specialist can provide a thorough assessment, identify the specific root causes of your symptoms, and design a personalized rehabilitation program.

Conclusion

The intricate connection of the kinetic chain means that a seemingly localized issue like knocking knees can indeed contribute to systemic problems, including lower back pain. By understanding the biomechanical links and addressing the underlying muscular imbalances, individuals can effectively mitigate the stress on their lower back and improve their overall movement quality and pain-free function. A proactive and holistic approach, focusing on strengthening weak muscles, improving mobility, and retraining movement patterns, is key to managing and preventing this common issue.