Will I hurt my knee if I do running exercises?

Q: I do exercise daily almost for one hour. This includes running, stretching, bending exercises. I want to know: 1. whether running on hard surface such as on tar roads can damage my knee joints? 2. whether rotating knees in a clockwise or anti-clockwise can make any injury to knees? I had been told long back that knees should not be rotated in a circular direction as mentioned above. This may cause internal injury to the knees. No of physical institute has stopped such type of exercises.

A:If you wear shoes which have an adequate cushioning, then the risk of injury to the joints can be minimised but not all together removed. In general, it is safer to run/jog on a softer surface, (like a mud track) especially if you are prone to joint discomfort or injury. Knee rotation can be continued if you have been practicing it for a long time and there is no discomfort to the knees. If you feel uncomfortable, you would have to check it with a doctor.