Q: Do you treat knees?
A: Yep, if it’s a joint we’ll usually treat a problem associated with that joint & knees are no exception.
We’d usually take a case history about how & when the knee pain/problem started and then examine it.
The examination would also probably include related areas like the hip and ankle/foot as well as gait (how you walk) in case the knee was being affected by other joints in the kinematic chain.
There are many causes of knee pain. Some are age related; like Osgood Schlatters disease in the young or osteoarthritic changes in the older patient.
It may be that the pain is being caused simply by a strain of a muscle like Popliteus which is responsible for correct functioning of the knee.
Whatever the cause, it needs a proper examination and perhaps a couple of x-rays to try to get to the root cause of the injury before treatment can begin.