Over many years, it has been believed that the repetitive action of running increases the risk of developing arthritis in the knee and hip. Without the accurate imaging that is available today, it would be obvious to hazard a guess at running being a risk factor. After all, our joints aren’t designed to withstand the forces involved with running long distances, right?
First of all, what is arthritis?
Osteoarthritis (OA) is a common condition and effects around 20 million people in the USA alone. It is often thought of as degeneration or wear and tear of the bone. Evidence now shows that OA is a process that involves many structures of the joint, including the synovial fluid (acts as a shock absorber), underlying bone, the joint capsule and other joint tissues.
With this degeneration, space between the joint can be lost, whether it is in the lower back, neck or knee. Often, in regards to the knee, the space on the medial side of the knee is often lost, which can cause the knee to adopt a position pointing inward. Symptoms are often reported as a deep ache in the joint, limited range of movement and often worse in a morning and eases once mobile.
The most common risk factors for OA are;
· Age (80-90% of people over 65 have signs of arthritis, it isn’t always symptomatic)
· Repetitive use???
If repetitive use is a risk factor, shouldn’t that correlate with running? Surprisingly not. Various evidence, including imaging of the knee shows no significant difference when comparing elite runners (100km per week) to those who run 20km per week.
Theories suggest that knee OA is predisposed by a collective amount of force on the joint over a period of time, this is called cumulative load. When compared to walking, running has a higher peak load per stride (as a higher load goes through the joint with each stride), however the cumulative or average load per stride over the same distance as walking is quite the same.
Another suggestion is that cartilage in a healthy state, adapts to the load and is able to withstand the greater stress frequently sustained when running. The exact reasoning is not definite, more research is needed but there is enough evidence to indicate that, if someone does not have predisposing risk factors, there is no correlation between running and knee OA.
Various problems can occur with the knee joint, its important to accurately identify the causation and effect to manage the pain and tackle the problem at hand. As an Osteopath, a hands-on assessment helps to do so.
Don’t be scared to run, it won’t ruin your knees.
Josh Kelsall (M.Ost)