The knee is a joint that often spurs a patient into booking into clinic. We’ve touched on it before, from a few different perspectives:
This post will focus more on the joints’ relationships with other areas, and general advice to keep it as happy as possible.
The Overall Anatomy
Although we think of the knee as a single joint, it is actually made of three.
- The main hinge joint between the femur (thigh bone) and tibia (shin bone)
- The joint between this area and the patella (knee cap) – the patellofemoral joint
- The smaller joint on the outside between the tibia and fibula
Ligaments support the complex. The cruciate ligaments (ACL and PCL) prevent too much forward or backward slide. The collateral ligaments (MCL and LCL) limit lateral movement or “gapping”.
The Knee’s Likes and Dislikes
The primary movement of the knee is simple flexion (bending) and extension (straightening). There is some allowance for accessory movements too: slight gliding and gapping. One movement the knee absolutely does not like is rotation, especially if it happens while weight bearing. This puts force through the two menisci that they are not capable of handling, and can cause tears.
Using the whole range of flexion and extension is good for joint health. It ensures that all cartilage on the joint surfaces is compressed and decompressed, giving it the opportunity to expel waste and absorb nutrients. The overall movement also encourages the fluid in the joint to refresh, further clearing waste and bringing in new nutrients. This is the underlying logic behind movement to discourage or manage the development of osteoarthritis.
That said, traumatic hyperextension is a common method of injury for the ACL. This can happen when landing awkwardly after a jump, which puts a lot of force through the leg and can cause a rupture as the ACL tries to prevent the movement.
Impacts of Exercise
Sometimes we hear people pass off their aches and pains as simply age related, then they compare the symptomatic area to a car- like there are only so many miles you can anticipate to get out of a joint. The difference between a body and a car is their reactivity: the body will react to the demands placed on it whereas a car will simply wear out. Cartilage is a great example of this; although arthritis is colloquially known as “wear and tear”, it’s not that simple. Overuse or misuse, as well as under-use, are more accurate causes to blame.
It is true that exercise will put demands on some areas more than others. But gently graded exercise will actually encourage the affected cartilage to thicken and provide more protection. That said- there is a limit. People who do unusually intense or prolonged exercise are at higher risk of osteoarthritis. Despite this, there is still no guarantee that ultra-marathons will give you arthritis, as the development of the condition is dependent on a number of factors.
Click here to make an appointment for your knees in Wiltshire
