Evidently So
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Over the past few years, a buzz-phrase – evidence-based practice – has gained favor in the physical therapy (and medical) community. EBP is an effort to encourage healthcare professionals to examine and critique their treatments and interventions for solid, scientifically-supported evidence that affirms the validity of their choices. Simply stated, there is a feeling that it is no longer enough to say we are justified in performing a particular technique or specific treatment regimen simply because “that’s how it’s always been done,” or, “so-and-so says this works great.” While there is a place for experience and consensus in the decision-making process of selecting a treatment plan, the emphasis now is to choose those interventions that have been shown to be clinically effective by means of controlled studies.
The development of such evidence often lags behind the innovation of new techniques and treatments. There will always be some interval of time between the initial “discovery” of a new idea or process and the “proof” that what was asserted is actually valid. When that evidence is provided, those who have been “true believers” in such theories are rewarded with a sense of gratitude (and relief!) that their viewpoints have been confirmed, or at least strengthened. A recent series of journal articles provides a good example of this.
An early two-part entry in this series (Articles #15 and 16) looked at the injury usually called “runner’s knee.” Known by several names – patellofemoral pain syndrome (PFPS), anterior knee pain, chondromalacia patella – this problem is one of the most common running injuries, affecting the back side of the kneecap. As described previously, this disorder occurs when the cartilage on the back of the kneecap (patella) is damaged. In the runner, the damage is the result of repetitive stress that causes excessive pressure to a small section of the cartilage. We usually blame poor tracking of the patella in the femoral (thigh bone) groove in which it rides up and down as we bend and straighten the knee. This off-track movement causes an imbalance in the compressive pressures to the back of the patella, which causes the breakdown of the cartilage.
When evaluating the causes of this tracking problem, physicians and therapists would traditionally look first at the balance and strength of the four muscles (quadriceps) that move the patella. Treatment would be directed towards selectively strengthening those muscles that would promote proper alignment and movement of the patella. Sometimes this worked well but, if not, surgeons might elect to “release” a tight muscle or realign the patella so that it will slide in the groove properly. Again, sometimes this worked …
After a while, some therapists began to theorize that the tracking problem might not be due to this alleged quad muscle imbalance causing the patella to move improperly on the femur, but rather by the femur moving improperly underneath the patella. Two factors thought to cause this were overpronation of the foot and/or muscle imbalances and improper rotational or side-to-side movement patterns of the hip joint. Therapists treating PFPS in this manner found considerable success in rehabilitating this injury, but the evidence was strictly anecdotal – until now.
The most recent edition of the Journal of Orthopedic and Sports Physical Therapy (November 2003) devotes the entire issue to the question of PFPS, its causes and management. Among the articles is a study that demonstrates the relationship between hip strength and PFPS, a 2-case study on the management of PFPS by targeting hip, pelvis, and trunk strength, and a review of the theoretical and research basis to support the use of foot orthotic devices to manage lower extremity movement, thereby normalizing the movement of the femur beneath the patella.
The articles in this issue of JOSPT clearly are just a starting point in the scientific investigation of the extrinsic causes of PFPS, but they provide the best evidence yet that this “indirect” approach to managing runner’s knee has a valid theoretical basis and, most importantly – it works!