The knee joint is more complicated than first meets the eye – the seemingly simple hinge joint is the location of the largest sesamoid (floating within a tendon) bone in the body, the thick meniscal cartilages and 4 main ligaments. If you have knee pain, understanding the nature of the joint is the first step in understanding the cause of your pain and how to solve it.
A Big Mover
The knee bends to an impressive range in the healthy individual – but did you know you have other small movements that the knee performs to compliment it’s main bending movement? To bend, the knee first rotates ever so slightly to “unlock” itself. The quadriceps muscle uses the knee cap as a fulcrum to exert force “around the corner” of the bent knee, to straighten it back out. This is why we have a knee cap, otherwise we wouldn’t be able to straighten our legs!
When the knee is straight we have very small side shifting movements available to prevent damage to the internal knee structures should we take a little stumble.
Menisci Make It Fit
Our femur (thigh) bones and tibia (shin) bones are two very different shapes, and they don’t fit together particularly well where they meet one another in the knee. To make them fit together better, we have two big wedges of cartilage called menisci in each knee. They’re just like using a washer when you tighten a bolt – they allow flex and movement, while keeping everything nice and congruent (well fitting).
Lots of Ligaments
There are 4 main ligaments in the knee joint. One either side, bracing the thigh to the shin, called the collateral ligaments. These ligaments help to make the knee strong to sideways movement.
There are then two internal ligaments of the knee called the cruciate ligaments, which can be quite easily damaged with shearing forces. Inside the knee one ligament comes from the front to the back of the knee, and the other comes from the back to the front. In the middle of the ligaments, they loop around one another – which is why they can be damaged if your toe gets stuck, just as in a misplaced football kick, or a skiing accident.
If you have a painful knee, or a knee that’s limited in movement, it’s a good idea to have your local osteopath take a look! They’ll be able to help you work out the cause and how to rectify the problem.
