Is running bad for your knees and what about continuing to run if you ALREADY have knee osteoarthritis? 

Time and time again we hear about and see runners who are advised to stop running because of knee pain due to a diagnosis of knee osteoarthritis based on symptom presentation with and without an X-ray. This means that a runner has been told they have osteoarthritis of the knee based on signs and symptoms (what you tell the health care professional and based on testing movements they or you perform without investigations) and then confirmed by an x-ray (investigation) that shows “degenerative changes”. 

FACT: Hyaline cartilage has no nerve supply, so it is not capable of causing pain. Cortical bone has a nerve supply so is capable of causing pain. Unless the degenerative changes or osteoarthritis have become so severe that there is no longer any hyaline cartilage within the knee joint and it is just the cortical bones sliding against each other then osteoarthritis cannot cause pain. Look at the third image which shows a real knee joint with all the tendons, ligaments, nerves, muscles and connective tissue in tact. All of these structures have a nerve supply so are capable of causing knee pain!! 

Also consider that usually the pain is only in one knee and the x-ray is usually only performed on one knee so there is rarely a comparison. It is highly likely that both knees on x-ray would show the same amount of “degenerative change”, “osteoarthritis”, “wear and tear”, which does not make sense when the pain is only in one knee. 

If degenerative changes shown in joints are so painful then why are we as physiotherapists not completely overloaded with the ageing population that are constantly in pain??? The facts are we aren’t!! 

Knee Joint Front 

Knee Joint Rear

A real knee joint from the side (outer)

The good news is that further research has just been released that continues to support the mounting evidence that running is not bad for your knees! Read the infographic and the supporting text below.

Running is safe and healthy for your knees 

• Habitual runners have 1/3rd the rate of knee and hip osteoarthritis compared with sedentary individuals. Cartilage quickly (<1 hour) recovers from a run, demonstrating no lasting effects. 
•  Running does not appear to accelerate the progression of knee osteoarthritis in runners
• Runners aged 50+ or over and runners with knee osteoarthritis reported more improvement in knee pain compared with non-runners with osteoarthritis over a 4 year period. 

What should you do if you are a runner and have knee osteoarthritis? 

Runners with knee osteoarthritis should feel safe to continue running, since running does not appear to accelerate the progression of existing knee osteoarthritis. A good strategy to consider is to reduce daily run volume whilst considering more frequent running (5 moderate length runs per week might be better tolerated than 3 longer runs per week) if you are experiencing symptoms. 

Given the overwhelming evidence supporting the general health benefits of running, it is currently not good practice to advise a runner with knee osteoarthritis who is managing their symptoms to cease run participation. 

Continue to lace up those shoes and keep running people. If you are in pain then seek help as the pain is highly likely to be arising from another structure and not the cortical bone. 

Reference 

Alexander JLN, Willy RW, Culvenor AG, Barton C. Br J Sports Med EPub ahead of print: doi:10.1136/bjsports-2021-10432