Many of us suffer from chronic pain in the knees, hips or lower back. Often there is a connection between these complaints and the way you walk. This article sheds more light on knee pain and in particular how abnormal foot mechanics or asymmetry in our gait can affect knee function, causing pain and discomfort.

Typical knee pain symptoms...

"A sharp pain in the knee and a grinding sensation, especially when getting up out of chair or walking up stairs."

This description of knee pain is most common and refers to a condition called Patello-femoral Syndrome. Patello-femoral Syndrome is the most common form of chronic knee pain. It refers to pain occurring between the knee cap (the patella) and the underlying thigh bone (the femur). Patello-femoral Syndrome causes pain and tenderness in the front of the knee. The pain gets worse when you sit for a long period and get up. Or when you walk up stairs. Often, one will experience a grinding or crunching sensation in the knee.

What exactly causes knee pain?

There are number of different causes for knee pain. With age wear and tear occurs in the knee joint. Also over-use causes knee problems (for example in rugby/football players, and in tradespeople such a carpenters, bricklayers etc). Over time softening of the cartilage beneath the knee cap (the patella) will result in tissue breakdown and pain in the knee joint. Instead of gliding smoothly over the knee the knee cap grinds against the thigh bone when the knee moves. In turn this may result in heavy erosion of the cartilage. Apart from age and over-use the third most common cause of knee pain is faulty gait (i.e. the way we walk). Overpronation (=rolling inwards of the feet and lowering of the arches) is a major contributing factor to knee pain.

Here's why...

The knee joint forms the link between the upper and lower leg. It is a hinge joint, which means it is only designed to flex and extend the lower leg, and not to rotate it. Unlike for instance your elbow joint which allows your underarm to move up and down, as well a twist (rotate). Overpronation of the feet means that with every step your foot rolls inwards too much. As the foot rolls inwards the bones in the lower leg are forced to rotate internally and this results in a twisting motion at the knee joint. This irregular motion of the knee will inevitably lead to excessive wear and tear in the knee joint causing long-term damage and chronic knee pain. Over-pronation not only causes bad knee function. An estimated 70% of the population suffers from some degree of over-pronation and this becomes evident in other areas of the body, especially at an older age. People with overpronation can display symptoms such as frequent ankle sprains, pain in the arches, leg pains, shin splints, hip pain, even lower back pain.

Treatment options for knee pain

The most commonly prescribed treatments by physiotherapists include rest (or decreased activity), ice packs and sometimes wearing a knee brace and also strengthening exercises. In addition, orthotic shoe inserts will be recommended to stabilise the feet and correct poor foot function. Footlogics orthotics can be used to prevent the unnatural rotation of the lower leg, thereby treating the cause of this type of knee pain. By supporting the arches they force the ankles and legs back into alignment, reducing the twisting on the knee and thereby providing relief to the painful knee joint.

A number of studies have shown that bad knee function can be restored by using foot orthotics. Below are the extracts of two of these studies:

Study 1) The Effect of Foot Orthoses on Patellofemoral Pain Syndrome (Knee Pain) - Amol Saxena, DPM and Jack Haddad, DPM - Department of Sports Medicine, Palo Alto Medical Foundation, Palo Alto, CA.

In a retrospective review of 102 patients treated for chondromalacia patellae and patellofemoral knee pain syndrome/retropatellar dysplasia (PFPS/RPD), the effectiveness of semiflexible foot orthotics was investigated. The combined disorders were diagnosed in 89.3% of the patients. Subjects were 46 women and 54 men, aged 12 to 87 years (mean, 37.9 years; SD, 15.9), who exhibited excessive forefoot varus or rearfoot varus. The initial screening and clinical diagnosis were based on an examination by an orthopedist. Particular attention was directed to patellar crepitation, patellofemoral malalignment, Q-angle measurements, limitation of range of motion, and knee effusion. Patients were evaluated for the onset and duration of patellofemoral pain and degree of knee joint disease. Semiflexible orthoses for each subject were fabricated, based on a clinical lower extremity biomechanical examination. At their follow-up visit, 76.5% were improved, showing a significant decrease in the level of pain with orthotics intervention (chi-square P < .001). Although multiple treatment modalities are used for these patients, the results suggest that the use of semiflexible orthoses is significant in reducing symptoms of PFPS/RPD. (J Am Podiatr Med Assoc 93(4): 264-271, 2003)

Study 2) The Role of Foot Orthotics as an Intervention for Patellofemoral Pain (Knee Pain) - Michael T. Gross, PT, PhD1- Judy L. Foxworth, PT, MS, OCS2

Foot orthotics often are prescribed for patients with patellofemoral knee pain. The purpose of this clinical commentary is to review the theoretical and research basis that might support this intervention and to provide our own clinical experience in providing foot orthoses for these patients. Literature is reviewed regarding (1) the effects of foot orthoses on pain and function, (2) the relationship between foot and lower-extremity/patellofemoral joint mechanics, (3) the effects of foot orthoses on lower-extremity mechanics, and (4) the effects of foot orthoses on patellofemoral joint position. The literature and our own clinical experience suggest that patients with patellofemoral pain may benefit from foot orthoses if they also demonstrate signs of excessive foot pronation and/or a lower-extremity alignment profile that includes excessive lower-extremity internal rotation during weight bearing and increased Q angle. The mechanism for foot orthoses having a positive effect on pain and function for these patients may include (1) a reduction in internal rotation of the lower extremity; (2) a reduction in Q angle; (3) reduced laterally-directed soft tissue forces from the patellar tendon, the quadriceps tendon, and the iliotibial band; and (4) reduced patellofemoral contact pressures and altered patellofemoral contact pressure mapping. Foot orthotics may be a valuable adjunct to other intervention strategies for patients who present with the previously stated structural alignment profile. J Orthop Phys Ther 2003;33:661-670.