ACCESSORY, BUT MAYBE MORE IMPORTANT!!!
Your knee joint is not as simple of a joint like we’ve been lead to believe. The knee joint is considered a ‘hinge joint’ traditionally, meaning that it can only bend and extend like a hinge for a door. From a reductionistic and mechanistic view of the human body, this would be accurate enough. However, your body is not like a machine. It is three dimensional and functions as much.
When examining the knee, the major motions about the knee joint are flexion and extension, or bending and extending, however there are subtle accessory motions that as far as the knee is concerned is much more vital in functioning and health for the knee joint.
ACCESSORY BUT VITAL
The subtle accessory motion that I am referring to is the rotation of the tibia (lower leg bone) and femur (thigh bone). There is quite a degree of rotation in a healthy fully functioning knee as you can see in this video.
This accessory motion is seen when we do a simple task such as walking. When we walk and land on the ground, our tibia (lower leg) rotates inward until we start to transition our weight onto the other leg, at which point the tibia starts to rotate outward. As you can see, this subtle motion that we mostly don’t think of or are even aware of is involved greatly during even the simplest of motions such as walking.
When you start to lose this range of motion you can start to expose yourself to various injuries and pain, in fact osteo-arthritic changes develop due to a loss of tibial rotation at the knee.
ADAPTABILITY, THE SAVING GRACE
Fortunately, your body has the ability to adapt by having other joints that perform a similar motion help out. The hip and ankle joint perform a similar rotational motion, that when you aren’t able to produce at the knee they can compensate. The ability for your body to compensate however can only last so long. Your credit card that you use to pay for cash you don’t have on hand will eventually reach a limit. Once that limit is met, your purchasing capacity is…well…also at its limit. Similarly, you can lose your capacity to compensate at other joints.
Therefore, it is important to take the time to maintain, and in most people’s cases, improve the accessory motion at the knee. You can test how much rotation you have at your knee joint simply by having feet flat on the ground with knee roughly at 90 degrees. Now keep heel down and hold knee on either side so it doesn’t move and try to rotate foot in as far as you can, then out as far as you can. You should be able to have your pinky toe go past the centre of your knee when you rotate in. And When rotating out, you should easily clear your knee with your big toe.
(the pen represents the midway point of your knee)
How did you do? If you had difficulty or a lack of motion, regaining that is of utmost importance.
POST SURGICAL IMPORTANCE
This is of special importance for those who have had knee surgery in the past. Intra-articular effusion (swelling in the knee joint itself) will lead to neuro-inhibition of a key muscle to tibial rotation, your popliteus. This muscle is intimately related to your knee joint capsule as well as sharing connection with your meniscus and a knee ligament. Thus a lack of function in this muscle will lead to poor loading of the knee joint structure mentioned above, your meniscus. This can lead your exposed to meniscal injury.
At the clinic we can restore that lost functional capacity in this muscle, and restore optimal tibial rotation through precise use of electro-acupuncture within a single treatment. I cannot stress the importance of doing that for long term health.
If you have questions on this or need some help with knee or other body related pains and limitations contact me here.