The hip and knee are anatomically very close to one another. Functionally, there are several muscles that attach above the hip and below the knee joint. Hence, depending on the position and/or activity, the same muscle can move the hip and/or the knee. This close relationship crosses over in dysfunction as well, as patients with knee pain move differently, and the hip joint is ultimately affected. But which one is the real culprit, the chicken (hip) or the egg (knee)?
In a quest to answer that question, one study asked patients with patellofemoral pain (PFP) and without hip pain to perform either knee exercises or hip exercises. Each group consisted of nine men and nine women. The knee exercise group performed quadricep or knee strengthening exercises while the hip exercise group engaged in hip strengthening exercises. The specific hip exercises included hip abduction (outward resistance) and hip external rotation muscle strengthening exercises. Both groups performed their exercises three times per week for a total of eight weeks. All participants experienced improvements in pain and function; however, the patients in the hip exercise group reported greater improvements than those in the knee exercise group. These results persisted for the next six months.
Why did hip exercises help patients with PFP knee pain MORE than knee-specific exercises? Weight-bearing dynamic imaging studies (x-rays) have shown that patients with PFP knee pain frequently have a lateral or outward displacement of the knee cap as well as lateral tilt due to femur/hip internal rotation (IR) rather than just abnormal patella motion due to muscle imbalance (the “old” theory).
Other recently published biomechanical studies have reported that persons with PFP demonstrate excessive internal rotation and adduction (inwards positioning) of the hip that isn’t generally observed in pain-free subjects. Further, those with PFP tend to have weak hip abductors, extensors, and external rotator muscles than pain-free individuals.
Chiropractic care focuses on whole body care, and patients are often surprised that doctors of chiropractic frequently treat hip, knee, ankle, and foot conditions. Posture and gait assessments, which may be included in an initial patent examination, frequently reveal abnormal movement patterns, leg length discrepancy, pelvic rotation, and lower lumbar spine dysfunction that may contribute to a patient’s chief complaint. Often, treatment must address these issues for the patient to achieve a successful outcome.