Patellofemoral Syndrome (PFS), often called “runner’s knee,” is a common musculoskeletal condition defined by pain in the front of the knee. While the connection between knee pain and hip discomfort may seem counterintuitive, PFS can indeed cause hip pain. The body functions as an interconnected chain of joints and muscles, known as the kinetic chain. This means a mechanical problem starting at the knee can directly influence the mechanics of the hip joint.
Identifying Patellofemoral Syndrome
Patellofemoral Syndrome is characterized by a dull, aching pain felt under or around the patella (kneecap). Symptoms typically worsen during activities requiring repeated knee bending or sustained flexion under load, such as climbing stairs, squatting, or kneeling.
A common symptom is pain after prolonged sitting, often called the “movie theater sign.” Some individuals may also hear or feel a grinding or clicking sensation, known as crepitus, when the knee is bent and straightened. This discomfort is often related to altered loading of the kneecap, which can be due to overuse or an imbalance in the muscles controlling its movement.
The Biomechanical Path to Hip Pain
Hip pain is frequently a secondary issue resulting from the body altering its natural movement patterns to protect the painful knee. This is driven by the kinetic chain, where movement changes in the knee cause stress transfer up the leg. When the knee is painful, an individual instinctively changes their gait to offload the patellofemoral joint.
This altered movement often manifests as dynamic knee valgus, where the knee collapses inward during weight-bearing activities like running or jumping. This inward collapse is linked to weak hip stabilizing muscles, specifically the gluteus medius and gluteus maximus, which control hip abduction and external rotation. When these stabilizers are weak, the femur rotates excessively inward and adducts, placing greater stress on the knee joint and forcing improper patellar tracking.
The hip pain arises from chronic strain on the surrounding tissues compensating for the lack of gluteal control. Constant internal rotation of the femur can place excessive tension on the iliotibial (IT) band, a long strip of connective tissue running down the side of the thigh, potentially leading to IT band syndrome. Altered mechanics and muscle imbalance can also overload the tendons and bursae around the greater trochanter, the bony prominence on the side of the hip, potentially resulting in trochanteric bursitis.
Addressing Knee and Hip Pain Together
Because PFS and subsequent hip pain are interconnected, effective treatment requires a holistic approach addressing the entire lower extremity kinetic chain. Physical therapy is the centerpiece of this management, emphasizing the restoration of muscle balance and proper movement patterns. Focusing solely on the knee is often ineffective if the underlying mechanical drivers originating from the hip are ignored.
The strengthening protocol must prioritize the hip abductors and external rotators, such as the gluteus medius and maximus, to stabilize the pelvis and control femoral rotation. Exercises like side-lying hip abductions, clamshells, and single-leg deadlifts are commonly used to build this proximal strength. Research indicates that incorporating hip strengthening yields superior results in pain reduction and functional improvement compared to knee strengthening alone.
Beyond strengthening, physical therapy includes neuromuscular training and gait retraining. This ensures the new strength translates into correct functional movement, helping the patient consciously correct excessive hip adduction and internal rotation during activities like walking. Supportive measures, such as over-the-counter or custom orthotics, may also be recommended to stabilize the foot and ankle, influencing the alignment of the kinetic chain.
For short-term relief, pain management may include the temporary use of non-prescription nonsteroidal anti-inflammatory drugs (NSAIDs) and the application of ice after activity. These measures manage symptoms while long-term mechanical correction is achieved through a comprehensive rehabilitation program.