By Bridget End, PT, DPT. How many times have you told people that you run and the response that you get is, “Isn’t running bad for your knees?” As a marathon runner myself, I have heard that question countless times. Yet, for years before becoming a physical therapist, I didn’t know how to respond. Is running bad for my knees? Will I eventually develop osteoarthritis? I didn’t know the answer, but I continued to log my weekly miles with the hope that I wasn’t doing any long-term damage! Upon doing my research, I found that many moderate to highly quality studies have been conducted to assess the impact of running on knee cartilage and the development of osteoarthritis. The evidence consistently suggests that no association has been found between running and the development of permanent cartilage or meniscus damage and knee osteoarthritis.1,2,3 Some studies did find a decrease in knee cartilage and meniscus thickness and volume, particularly in the more superficial and medial areas, immediately after running. However, these levels returned to normal within as little as 90 minutes for tibiofemoral cartilage and up to 48 hours for patellafemoral cartilage.1,2 Furthermore, in runners who already had some level of cartilage damage prior to the studies, they did not develop more damage over the course of the studies.3 Therefore, the current research suggests that the inherent act of running does not result in long term knee cartilage degradation or the development of osteoarthritis. That being said, as with any joint, poor biomechanics causing increased and abnormal forces on the joint can lead to injuries, both soft tissue and bone related. So, runners can develop knee injuries, such as patellofemoral pain syndrome and patellar tendinitis. These injuries are often due to muscle weakness, muscles tightness, improper footwear, excessive training load, etc. and can be prevented or rehabilitated to avoid permanent damage. The key is to identify the source of the issue, in order to treat the root cause and not just manage the symptoms. This is often easier said than done and can require the help of a healthcare professional (e.g. a physical therapist!). If you are currently experiencing knee pain, or if you want to prevent the potential development of knee pain, you can make an appointment with a physical therapist to develop the appropriate treatment plan. References: