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)

This entry is adapted from a talk presented by Physical Therapy of Los Gatos principal Rob Naber at the Western Occupational Health Conference 2005, held September, 2005 in Monterey, California:

Active Range of Motion (AROM) refers to the range of motion for a specific movement that a patient can achieve without assistance, such as a measurement of how far the back moves when a patient bends forward to touch his or her toes. The distance or angle between the starting and finishing position is the AROM. A reduction in AROM can impair routine, vocational, and athletic movements and overall functional capability. Restoring AROM following injury, surgery, or the effects of an illness on the musculoskeletal system is often the goal of physical therapy and the principal reason that many patients are referred to physical therapy.

In the past, physical therapists used goniometers to quantify lumbar AROM. Though practical for AROM measurements around knees and shoulders, the goniometer was of of very limited clinical utility as a means of measuring motions of the spine and surrounding joints. Other tools and methods, such as flexible rulers and measuring tapes, suffered from a lack of precision and reference values, and were also of little diagnostic value.

In 1984, Mayer, et al. proposed a method using specific inclinometer measurements to enable quantification of lumbar forward bending AROM and discrimination between the contributions of the hip and spine to the overall motion. In 1986, Keeley, et al. published a follow-up article that validated the reliability of the inclinometer-based technique and presented the reference values needed to make measurements made in the clinic meaningful.

While necessary as components of a complete evaluation, individual inclinometer measurements of lumbar AROM offer little information of clinical value and should not be used to report degrees of impairment. Multiple inclinometer measurements are necessary to determine the effects of the patient’s starting posture and the relative contributions of hip, pelvis, and lumbar joints to forward and backward bending. A patient can present with a normal lumbar AROM but still suffer from a “weak back” and recurring back pain and disability.

Physical therapy to restore a diminished lumbar AROM is not simply a matter of achieving a specific AROM value. A more nuanced therapeutic goal of restoring ideal ratios between the contributions of involved joints to composite lumbar motions will lead to more rapid and sustained reductions in impairment and more complete and satisfying recoveries.

Lumbar Spine Active Range of Motion: Significance and Relevance in Rehabilitation presentation by Rob Naber to the Western Occupational Health Conference 2005
Western Occupational Health Conference 2005: New Horizons in Occupational Medicine

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.

An unintended consequence of the increase in sports participation by girls and young women over the past thirty years has been an extraordinary rise in the incidence of anterior cruciate ligament (ACL) injuries in young female athletes. At the college level, one in ten young female athletes participating in sports such as soccer, volleyball, and basketball will suffer an ACL tear injury. These girls are typically unable to practice or compete for one or more seasons and face potential loss of scholarship funding and significant psychological trauma. A widely cited 1985 study found that at the high school level, the knee injury rate among female athletes is one per 100 participants, and noted the need for preventative measures.

In 1983, sports medicine researchers determined that four-fifths of ACL injuries are non-contact injuries, that is, they are caused by the athlete’s own motions rather than collisions with other players. To the researchers, this finding meant that the high incidence of ACL tear injuries in young female athletes might be greatly reduced if those motions could be identified and avoided.

The ACL is one of four major ligaments that connect the upper and lower leg at the knee. The ACL provides joint stability and supports cutting and pivoting motions. Oftentimes, the ACL will tear with a “pop” that can be heard by spectators and other players. Pain and immediate swelling follow. ACL tears require surgical reconstruction using tendon grafts from other areas of the knee or from cadavers, followed by a long period of rehabilitation.

The frequency and seriousness of ACL tears in young female athletes has led to research studies aimed at understanding the problem. These studies are now yielding valuable data. Three major hypotheses to account for the higher number of ACL tears in female athletes versus male athletes have been examined: hormonal differences causing laxity of the female athlete’s ACL, a smaller and more narrow space within the knee for the female athlete’s ACL, and sex-based differences in lower extremity strength and coordination. The last of these three hypotheses is receiving the most scientific support from study data.

Certain aspects of lower extremity strength and coordination can be captured and measured by videotaping athletes while they perform athletic movements in the research lab. While video recordings do not capture complex three-dimensional movements and the rotational stresses that these movements place upon the knees, the recordings do enable researchers to make close measurements of joint and limb positions in a single plane. These measurements were found to have predictive value.

In one well-designed study of 205 young female athletes, researchers found that athletes with a specific way of posturing their lower extremities, known as “valgus” (or “knock-kneed”) alignment, during certain athletic movements were more likely to suffer ACL injury than athletes with more “neutral” or straighter lower extremity alignment. This valgus alignment can be seen by analyzing the angles formed between the ankles, knees, and hips when the athlete lands from a jump off a small box and when she jumps vertically from a crouched position. A separate study that included videographic analysis of 325 young female athletes showed that a six-week neuromuscular training program corrected the lower limb valgus alignment associated with injury during jump landing and takeoff.

It is already well-known to physical therapists that muscular strength stabilizes the knee by helping to maintain the correct relative positions of knee structures during sports movements and by allowing muscles in the legs to absorb forces that would otherwise subject the joint to potential injury. But physical therapists treating young female athletes must now consider the implications of the new studies. Physical therapists familiar with these studies infer that rehabilitation from ACL injury should, in addition to conventional strength training treatment methods, include specific neuromuscular training aimed at improving the athlete’s ability to avoid valgus alignment of the lower extremities during high-risk sports.

It is no longer acceptable to reconstruct the ACL but leave neuromuscular control deficient.

The jump strength training program at Physical Therapy of Los Gatos is an element of rehabilitation from surgical reconstruction of the ACL as well as a standalone performance improvement module. The program includes jump analysis, strength conditioning, and neuromuscular training designed to improve power and acceleration. The neuromuscular training methods employed include visual, auditory and proprioceptive cues to train athletes to use muscular strength to absorb jump impacts in a controlled fashion, and, if necessary, to correct jumping, landing, and pivoting techniques in order to avoid forces associated with injury. For additional information about prevention of ACL injury, rehabilitation from surgical ACL repair, and jump strength performance training for athletes, please call Physical Therapy of Los Gatos at (408) 358-6505.