Auteur: Podiatre Montreal
How foot function can affect patellofemoral syndrome, knee arthritis and anterior cruciate ligament injuries.
Causes of knee pain
There are several causes for knee pain. The most common include patellofemoral syndrome, arthritis, ligament injury, meniscus tear, tendonitis and bursitis. Some of the causes of these problems cause injury, obesity, wear and tear over many years and abnormal foot function.
Link between foot function and certain knee pains
Abnormal foot function can cause several types of knee pain. Your feet are the foundation of every step you take; problems with foot function can have repercussions that are felt elsewhere, such as in the knees, back or hips.
In studies of knee pain and foot function, excessive flattening of the foot (pronation) is the most commonly reported problem associated with knee pain. Foot pronation causes the knee to rotate inward, forcing it to function in an abnormal position.
Orthotics for knee pain, arthritis and ACL injuries
Foot orthotics are a proven technique for treating and preventing certain types of knee pain such as patellofemoral syndrome and knee arthritis, and may play a role in the prevention of anterior cruciate ligament injuries. If you suffer from knee pain and want to know if it is caused by the function of your feet, make an appointment to come to our foot and ankle clinic.
It is important to note that while several studies have shown that orthotics can help some patients with these problems, this does not mean that they are effective for all patients.
While orthotics are sometimes an integral part of treatment, they can also be used as a complement to other treatments or not at all. We can help you determine if orthotics are a good solution to relieve your knee pain.
Orthotics for Patellofemoral Syndrome
Patellofemoral syndrome is caused by a displacement of the patella. Several studies have shown that when the foot is in excessive pronation (flat foot), the leg pivots inward and the patella is off its axis.
Studies have also shown that the use of orthotics to prevent the flattening of the foot (and therefore the rotation of the leg) can reduce the pain associated with the syndrome. In fact, a study conducted in 2003 by Gross showed a 67% reduction in pain with the use of a custom-made orthosis.
A study by Johnson in 2001 showed that the pain was reduced within 2 weeks. A 2003 study of more than 100 runners suffering from femoropatellar pain showed that 76.5% of patients noticed a significant reduction in pain when using a custom-made orthosis.
In 2003, a study with 102 athletic patients suffering from femoropatellar syndrome showed an improvement in 76.5% of patients in 2 to 4 weeks with custom-made orthotics. A 2004 study showed a significant reduction in femoropatellar pain with the use of a foot orthosis.
Orthoses to treat femoropatellar syndrome must be specifically designed to reduce leg rotation. When the right leg rotates inward, it offsets the patella and can cause patellofemoral syndrome. A foot orthosis prevents the foot from flattening and the leg from rotating and keeps the patella in the right axis. The best orthosis to achieve this result depends on the specific biomechanics of each patient, but often the best orthosis follows the arch of the foot very closely and covers the entire width of the foot. It should not crush under the weight of the Patient, but should still provide a good cushion.
Orthotics for pain caused by arthritis
Several studies have shown that highly specialized orthotics can help reduce pain in patients with knee arthritis. More specifically, these studies have shown that orthotics can help patients suffering from arthritis of the medial compartment of the knee. The knee is composed of two compartments, the medial (closer to the opposite leg) and the lateral (outside the leg).
Studies have shown that the use of custom-made orthotics with lateral or “valgus” wedges can reduce pain and pressure on the medial compartment of the knee. Our podiatrist doctor is an expert in designing orthotics for patients with medial knee arthritis.
Studies conducted in 1997, 2002 and 2004 have demonstrated with a solid scientific basis that custom-made orthoses with specific types of wedges effectively reduce pain in patients with medial knee arthritis. In 2005, in a study of 30 people with medial knee arthritis, patients received an orthosis with a 5 degree lateral tilt. After 6 weeks, all patients felt less pain and 28 found the orthoses comfortable.
Under what conditions do orthotics work to reduce the pain associated with knee arthritis?
- Studies have shown that orthoses are more effective in reducing pain in cases of arthritis affecting the inside of the knee. They are not effective in all cases, but they can be very helpful.
- Some patients see no improvement, and a small percentage experience more pain and cannot wear an orthosis.
- Orthotics for pain inside the knee are very specialized and standard foot orthotics can increase pain.
- Adjustments are often necessary to achieve better results. Make sure that the person who makes your orthotics is specialized in biomechanics and podiatry.
- Orthotics are not effective in relieving knee pain when arthritis is present in the medial and lateral compartments of the knee; they may even increase the pain.
- Orthotics may be effective in some cases of lateral knee arthritis, but no studies have demonstrated this. These orthoses require different shims than those used to relieve medial knee pain. Lateral arthritis is less common than medial.
- Although they reduce pain, there is no evidence that orthotics slow the progression of knee arthritis.
If you suffer from knee arthritis, come and see us at the clinic. Orthotics can be a good tool to relieve the pain caused by knee arthritis in some patients as part of treatment.
Orthotics to prevent anterior cruciate ligament injuries
Medical literature provides evidence that the use of custom-made orthotics can reduce the risk of anterior cruciate ligament injury.
Research was conducted on a college-level women’s basketball team over a 13-year period and was published in 2008. In the first phase of the study, which lasted 4 years, the team did not use an orthosis.
In the second phase, which lasted 9 years, all team members received a foot orthosis. When the authors of the study analyzed the number of ligament injuries, they found that players who did not wear an orthosis were 7.14 times more likely to suffer an ACL injury.
In addition to the 2008 publication, several studies have shown that when the foot is in pronation (flat foot), the leg pivots inward. This increases the strain on the ligament, which increases the risk of injury.
Who should wear orthotics to prevent ACL injuries?
We do not believe that everyone should wear orthotics to prevent ACL injuries. Based on the results of this study, it is prudent for anyone with a history of ACL injuries to wear orthotics. In addition, women are at greater risk for this injury, so women who participate in high-risk sports (basketball, soccer, etc.) may want to wear foot orthotics as a preventative measure (especially those with excessively pronated feet).
What type of orthosis can prevent ACL injuries?
Our goal, when prescribing orthotics to prevent ACL injuries, is to limit leg rotation to decrease the strain on the anterior cruciate ligament. This is achieved by limiting the pronation of the foot as much as possible. This requires a very specialized orthosis. We usually recommend a total contact orthosis with several features that increase control.
Treatments for knee pain other than orthotics
There are as many possible treatments as there are causes for knee pain. It is very important to understand the cause of the symptoms before starting treatment. Our first job is to determine if the function of your feet is contributing to your pain. We do this by means of an evaluation, and sometimes by giving you a temporary orthotic to check its effect on your pain. If we believe that your pain is not related to the function of your foot, we will refer you to a specialist for another type of treatment.
What type of brace works best for knee pain?
Studies have shown that the best orthotics to use vary according to the type of knee problem you have. A person with pain inside the knee needs a completely different type of orthosis than someone with pain outside the knee. In addition, knee orthotics often require adjustments after a few weeks of use. For most (but not all) knee problems, orthotics need to follow the arch of the foot very closely. For these reasons, it is essential that the person prescribing orthotics be specialized in molding, prescribing and fitting foot orthotics. Our podiatrist doctor is an expert in podiatry and our clinic is a reference for patients requiring state-of-the-art biomechanical treatment.
If you suffer from knee pain and want to know if treating the function of your foot might help, call us today to make an appointment.
What should you bring to your appointment?
If x-rays of your knee show signs of arthritis, bring them to your appointment. If you don’t have x-rays of your knee yet, you will need them before having your brace made. If both compartments of your knee are affected by arthritis, you must inform us; some patients in this situation do not tolerate foot orthotics well.
- Bring short pants or pants that you can roll over the knee.
- We will probably perform an analysis of your gait (how you walk), the function of your foot and knee.
- After the exam, we will tell you if orthotics can help relieve your pain.
- If an orthosis is prescribed, be aware that after reception, several visits may be necessary to find the best adjustment to reduce your pain as effectively as possible.