Knee pain is fairly common - around one in four adults experience it at some point in their lives - and it often seems to get worse after walking. Many people assume it is simply due to age, but in many cases there is an underlying cause that may be treatable. Figuring out the root cause of the pain is important, as it helps guide recovery and prevent long-term issues. How the Knee Works The knee is one of the most complex and hard-working joints in the body. It is made up of