This week, I'm answering a question from a reader. It's a subject we hear a lot about and is one of our more popular posts on knee pain. In fact, this question or something like it hits either our blog or my inbox just about every week. So, following the comment below, are my thoughts on how to overcome Patellfemoral Syndrome.
Doug - I'm grateful for your post.
I'm currently doing research into Patellofemoral Syndrome rehab, as I've been suffering with knee pain in my right leg after running, on and off for 3 or 4 years. I have seen a physio four times over the last couple of weeks, who diagnosed the issue as a maltracking patella, caused by a combination of overpronation and a weak VMO. I've been given a selection of exercises and 'treatments' to address the issue and reduce pain during exercise. These include:
1. Stretching of hamstrings, quads and calf muscles (all are very tight, hamstrings are particularly short).
2. Theraband balance exercises and quad strengthening exercises (straight leg raises, partial squats etc.) - all outside the pain zone.
3. Molded orthotics for running and every-day shoes.
4. Strapping/taping instructions for when I need/want to exercise with reduced discomfort.
Although I acknowledge your point on isolation of the VMO, are you making any alternative suggestions for therapy, or would your opinion be that the above treatments are suitable and sufficient. Many thanks for your help.
Jules
Jules,
The list of treatments is not uncommon nor would I consider any of them to be inappropriate. But, the list is incomplete. And, yes, I do have suggestions on how to improve the solution.
The main problem with Patellofemoral Syndrome (PFS) is that the physical demand of the activity is greater than your physical capability. When the physical demand is too high, symptoms appear. For example, if you pull your index finger back slowly until you feel some resistance, you will notice a sense of tightness or pulling in your finger but it probably will not hurt. But, if you increase the pressure (the demand), your finger will begin to hurt.
When your foot hits the ground, the force of your body weight travels back up the leg and through the knee. The lining on the ends of your bones, the articular cartilage, disperses some of that force but when the cartilage is too soft (as in the case of Patellafemoral Syndrome), more of the force travels into the bone and other structures (tendon, ligament, joint capsule). As the force accumulates and exceeds the tissue capability, for example while running, your knee may hurt.
The treatments you listed are common so, here's the list again along with my impression of the purpose and the pitfalls:
1. Stretching of hamstrings, quads and calf muscles (all are very tight, hamstrings are particularly short).
Purpose: Tight muscles lead to more rapid increases in force production. A more elastic muscle would then logically absorb the force over a longer period of time.
Pitfall: If the muscle is tight from irritation of the joint (which is almost always the case), stretching proves to be exceptionally frustrating. You're flexible right after the stretching but within hours or days, you're just as tight as before the stretch.
2.
Theraband balance exercises and quad strengthening exercises (straight
leg raises, partial squats etc.) - all outside the pain zone.
Purpose: Stronger muscles help protect the joint.
Pitfall: The force required to fatigue the muscle is typically greater than what the joint can withstand. You either end up with a sore, swollen joint or muscles that have gained little strength.
3. Molded orthotics for running and every-day shoes.
Purpose: Orthotics alter the movement of the leg (tibia and femur) via the foot thereby reducing the pressure under the patella (kneecap) and improving general alignment of the leg.
Pitfall: Small changes in foot alignment can lead to large changes in joint pressures sometimes for the better and sometimes not. Secondary complaints of lower back or hip pain are common.
4. Strapping/taping instructions for when I need/want to exercise with reduced discomfort.
Purpose: Reduces pain by altering sensory input to the brain.
Pitfall: You have to wear tape and unless your exercise is designed to improve the joint health, you may exercise too hard and not know it....until later.
The missing ingredient is an exercise regimen targeting the soft joint surface. Almost every exercise program that you find for PFS targets muscle (quadriceps strengthening, stretching of the hamstrings, etc.) and having stronger muscles is helpful but weak muscles are not the primary problem. The muscular weakness is in response to the changes in the joint. Some clinicians argue that cartilage does not respond to exercise; that it is biologically inert. However, there is ample scientific evidence proving that cartilage does respond like other biologic tissues of the body (muscle, tendon, ligament, bone) as long as the motion-force combination is within a certain range. You may not be able to regenerate articular cartilage with exercise but you can certainly improve the health of the injured or diseased cartilage. And, healthier cartilage translates into increased physical capability.
The ideal combination is low force (no greater than 50% of of your identified Load Tolerance - our e-booklet, Torn Meniscus, provides more detail on Load Tolerance) combined with very high repetitions (thousands) to facilitate biologic adaptation of the cartilage. Week by week, your Load Tolerance should increase and typically within six to nine months, reach full body weight (some people have been able to accomplish this in two to three months).
Once you address the core issue, joint health, the other treatments become even more effective. So, my opinion is to target the joint first, muscles second, and other treatments third (taping, orthotics, etc.)
Doug Kelsey
Roos, E. M. and L. Dahlberg (2005). "Positive effects of moderate exercise on glycosaminoglycan content in knee cartilage: a four-month, randomized, controlled trial in patients at risk of osteoarthritis." Arthritis Rheum 52(11): 3507-14.
Doug -- Is it safe to do hip push ups instead of the bird dog? Here is an example video link:
http://www.posetech.com/video/index.php/weblog/2005/11/