The Spring 2006 West Valley College Sports Medicine Symposium was held May 5th. The symposium was organized by John Kao MD for an audience consisting of physical therapists, athletic trainers, and physicians. The purpose of the Sports Medicine Symposia series is to continue improving the standard of orthopedic medicine here in the Bay Area by providing orthopedic professionals an opportunity to share their knowledge with one another and with other medical practitioners. This year’s spring symposium focused on current challenges of treating the lower extremities.

The following local professionals gave presentations:

• John T. Kao, M.D.

• Grady L. Jeter, M.D.

• Robert S. Nishime, M.D.

• Thomas Elardo, D.P.M.

• Paul Christensen, DPT, OCS, ATC

• Rob Naber PT, OCS, ATC

• Ross Nakaji PT, OCS, ATC, CSCS

• Fabrice Rockich, DPT, OCS, CSCS

• Paul Starks, MA, ATC, PTA, CSCS

Physical Therapy of Los Gatos principal Rob Naber spoke about the evaluation and treatment of problems affecting the knee. Rob began by noting the value of recent knee research and the bearing of research findings on the practitioner’s approach to knee conditions and injuries:

“The knee is often the weakest link that defines and limits an athlete’s total competitive capacity. The knee is needed for speed, power and strength, but is also vulnerable to injury. A knee injury not only means missing practice or competition but may also lead to the loss of scholarship support and potential professional opportunities. Extensive research of the knee, and improved diagnostic, rehabilitation, and surgical methods have brought new hope to athletes and clinicians dealing with the challenges of the injured knee.”

– from Current Issues in Sports Medicine: The Knee presented by Rob Naber PT, OCS, ATC

One of the key takeaway messages from Rob’s presentation was the importance of quantifying the capability and condition of the knee while the joint is in motion. In the evaluation and treatment of anterior knee pain, for instance, measuring the concentric vs. eccentric torque capacities of the knee is critically important as a diagnostic aid and as a reliable indicator of treatment progress. In rehabilitation following surgical reconstruction of the anterior cruciate ligament, videographic analysis of lower extremity angles during landing and jumping provides data the therapist needs to design and carry out a course of treatment that brings about rapid restoration of function and corrects neuromuscular control deficiencies that would otherwise invite re-injury.

Using the links below, interested individuals can view visuals and handouts from Rob Naber’s presentation to the Spring 2006 West Valley College Sports Medicine Symposium. For more information about Physical Therapy of Los Gatos’ approach to the evaluation and treatment of knee problems, please call the clinic at (408) 358-6505.

Current Issues in Sports Medicine: The Knee (view presentation visuals)
Current Issues In Sports Medicine: The Knee (download text)

Jump Strength Training Program (download program description)

Jump Strength Training Glossary (download glossary)

Physical Therapy of Los Gatos principal Rob Naber spoke by invitation at the Western Occupational Health Conference 2005, held September 15 – 17 in Monterey, California. The annual conference is sponsored by the Western Occupational and Environmental Medicine Association, an educational and advisory organization that helps bring about and preserve legislation aimed at improving worker injury care. The organization is part of the influential American College of Occupational and Environmental Medicine.

As the only physical therapist invited to speak at the conference, Rob chose to present information on the diagnosis and treatment of knee and back maladies, which can result from on-the-job injuries and overuse.

Information on anterior knee pain has been previously published on this web site. Rob’s presentation on anterior knee pain to conference attendees contained additional clinical information of value to health care professionals involved in setting treatment guidelines for rehabilitation of work-related injuries.

Anterior Knee Pain: The Use of Eccentric Strength Exercise

presentation to the Western Occupational Health Conference 2005

Western Occupational Health Conference 2005: New Horizons in Occupational Medicine
Western Occupational and Environmental Medicine Association
American College of Occupational and Environmental Medicine

Anterior Knee Pain, also known as “runner’s knee,” is the second most common reason for joint pain related physical therapy office visits. Patients with anterior knee pain complain of a dull ache at the front of the knee that feels like it’s coming from behind the patella (kneecap). Patients feel pain most strongly after sitting for a long time with their knees bent, as in a long meeting or at the movies, and when walking downstairs or bending down into a crouching or squatting position. In almost all cases, anterior knee pain can be relieved temporarily by simply straightening the leg. Untreated anterior knee pain is often severe enough to limit knee function, requiring sufferers to discontinue sports activities, avoid stairs, and seek out seating that allows frequent full leg extension.

The exact cause of anterior knee pain is not known, and the condition is considered difficult to treat. Most interventions for anterior knee pain are based on one or the other of two popular theories: “chondromalacia” of the cartilage behind the patella, and “malalignment” between the patella and femur.

Chondromalacia in the context of anterior knee pain refers to softening and degradation of cartilage behind the patella. Chondromalacia is so commonly considered the cause of anterior knee pain that the word is often used incorrectly as a synonym for anterior knee pain.

Cartilage behind the patella is thought to allow the patella and the end of the femur to slide smoothly relative to each other when the knee joint is in motion. Chondromalacia theory says that anterior knee pain occurs when the cartilage is softened or degraded. Chondromalacia is treated by surgery aimed at encouraging new cartilage to grow inside the knee joint or by separating intact cartilage from its original location and moving it to sites where the surgeon believes it will be more useful.

Surgery to correct chondromalacia has not been shown in rigorously designed, statistically valid studies to provide long-term relief from anterior knee pain. This lack of effect is consistent with what we know about joint cartilage: joint cartilage does not have nerve endings and can therefore not be a source of pain. The absence of pain receptors in knee cartilage was confirmed in an unusual experiment carried out on orthopedic surgeon Scott Dye, MD, who reported no sensation during direct probing, without anesthesia, of the cartilage behind his patella.

The presence or absence of chondromalacia does not predict whether someone does or does not have anterior knee pain. Many individuals with advanced chondromalacia do not have anterior knee pain, and many individuals with anterior knee pain do not have chondromalacia.

Malalignment theory proposes that the patella is somehow crooked or is located too far to one side or the other of the knee, causing excessive friction and pain. A number of therapies aimed at correcting malalignment have been developed, including:

• using tape applied to the skin to try to hold the patella in a “medial glide” position
• specific muscle training exercises aimed at changing the position of the patella
• “lateral release” surgery to change the position of the patella

None of the non-surgical treatments for patellar malalignment have been shown to change the position of the patella for any clinically meaningful duration of time. Therefore, it has been difficult to detect a statistical correlation between malalignment and anterior knee pain. In addition, none of the non-surgical or surgical treatments based on correcting malalignment have been shown statistically to provide long-term relief of anterior knee pain.

Like chondromalacia, patella alignment or malalignment does not predict whether an individual will experience anterior knee pain. Chondromalacia theory and malalignment theory are also similar in that they are both based on observations made when the knee is not moving.

At Physical Therapy of Los Gatos, we view the knee as a dynamic process, and we believe that anterior knee pain must be evaluated while the knee is in motion.

Our approach to understanding and treating anterior knee pain is influenced by the work of Bennet and Stauber, who in 1986 noticed that, in individuals with anterior knee pain, the amount of torque produced around the knee joint by the quadriceps muscles during dynamic, eccentric exercise (when the quadriceps muscles are lengthening to allow the knee to bend) was not normal in its distribution around the axis of rotation of knees affected by anterior knee pain. Contrary to the differences normally observed between eccentric and concentric muscle strength, torque measured around affected knees was less than torque measured around the same knees during concentric exercise. Bennet and Stauber also found that specific exercises could restore eccentric torque and torque distribution to normal, and when that was accomplished, anterior knee pain went away.

Analyzing the relative torque-producing capabilities of the quadriceps muscles during eccentric and concentric exercise is a critical aspect of our approach to evaluating patients with anterior knee pain. In our experience, re-defining the eccentric and concentric torque profiles of the quadriceps can be readily accomplished by a motivated patient using specific exercises that emphasize eccentric muscle strength. This approach provides long-term relief from anterior knee pain and allows our patients to return to sports and other activities requiring normal knee function.