Valgus And Varus Knee Patterns And Knee Pain
Knee pain is complex, varied, and has many sources. Causes range from acute trauma, like broken bones, to chronic aches and pains with no obvious source. One potential contribution to knee pain can simply be our postural patterns. In this article, let’s take a closer look at a particular knee-related aspect of our posture that can sometimes lead to knee pain: valgus and varus knees.
What are valgus and varus patterns?
A valgus knee pattern is what is colloquially sometimes called “knock-knees.” In this case, the angle between the tibia and the femur on the lateral side is smaller than it should be ideally and that angle is wider on the medial side than the ideal. In contrast, a varus knee pattern, colloquially called “bow legs,” is the opposite. The angle between the tibia and the femur is reduced on the medial side and greater on the lateral side than what is considered neutral. To simplify the naming of these patterns, Tom Myers of Anatomy Trains and others refer to the valgus knee pattern as an X-leg pattern and the varus knee structure as an O-leg pattern.
Either of these patterns might be mild, with small variations in angle size in relation to what is considered neutral. In that case, the person might not experience any reduced function or pain. At the other end of the spectrum, these patterns can show up in more extreme variations. More extreme versions of these patterns can negatively affect function and sometimes cause pain.
What drives these knee patterns?
The source of these patterns is complex. It may be congenital, the result of disease complications, the result of acute trauma like a broken bone, or other reasons. And, these postural patterns don’t exist in isolation, of course. They’re in the middle of the whole lower kinetic chain between the pelvis and the feet and ankles.
For that reason, tension above or below can influence knee position. And, the reverse is also true. These patterns affect the way tension is held at joints above and below the knee. So both acute trauma, as well as patterns from chronic use acquired elsewhere in the body, can contribute to valgus or varus knee position.
Do you have a valgus or varus knee position?
Let’s do a little experiment to learn about your own posture. Stand in front of a mirror where you can see your knees. Slowly scoot your feet together. Notice which touches first, your feet or the insides of your knees. When you bring your feet together, do the insides of your knees meet first? Then, you have a valgus, or X-leg pattern. Do your feet meet first and do you also have significant space between your knees when your feet are together? Then you have a varus, or O-leg pattern. If your feet and the insides of your knees meet at about the same time, then your knee pattern is neutral with respect to an X-leg or O-leg pattern.
How are these patterns related to knee pain?
The knee is primarily a hinge joint. That is, it flexes and extends easily in the frontal plane. On both the medial and lateral sides of the knee are ligaments holding the knee in place and resisting any pressure too far in either direction. On the medial side is the medial collateral ligament. And, on the lateral side is the lateral collateral ligament. You could imagine then that if we chronically put pressure on either of these ligaments with a valgus or varus-positioned knee that those ligaments could get over-stretched and then irritated and sore after a while.
Additionally, we have both a medial and lateral meniscus. Remember our menisci are semi-circular discs that help cushion the knee. They allow the femur and tibia to glide past each other during movement. If we’re chronically putting more tension on either the lateral or medial side of our knee joint, then we can potentially pinch the meniscus on the side where the tibia and femur are closer together. That can also irritate the tissues in that area and cause soreness.
In both the X-leg and O-leg positions, the load-bearing force is not going through the center of the knee. Instead, the line of force is more off to one side or the other. That affects where tension goes. Over time it can increase the chances of osteoarthritis due to the extra stress either on the inside or outside of the knee and potentially result in pain (Miura et al., 2009). In an X-leg position specifically, the pattern has been linked to an increased likelihood of patellofemoral pain (Gwynne and Curran, 2018; Herrington, 2014).
Can we change knee patterns?
Yes, it is possible to change these patterns, to a point. But, if we really want to change them, we have to look more holistically at the body. There may be a genetic component to the angle of the joints at the hip, knee, and ankle. Those aren’t likely to change. Our knee position may also result from something we can’t change like a disease or acute injury.
But we also acquire our patterns from activities we do as well as accidents and injuries we’ve experienced. If those patterns are held in the soft tissue (muscles and fascia), then there is some potential to change them. We would need to consult with an appropriate medical professional like a physical therapist or experienced bodyworker for a full assessment to understand the range within which change might be possible for our pattern.
Valgus and varus knee positions describe the way the tibia meets the femur at the knee joint. They refer to a pattern where the knee is positioned either medial or lateral of the ideal. In this position, the knee is more vulnerable to some types of strain on tissues surrounding it, which may cause pain as well as reduced function.
Gwynne, C.R. and S.A. Curran. 2018. Two-dimensional frontal plane projection angle can identify subgroups of patellofemoral pain patients who demonstrate dynamic knee valgus. Clinical Biomechanics. 58:44-48.