Originally Posted by
twilkins9076
Standard wisdom that I've always heard is that you should cover your knees at anything below 60 degrees. I'm not sure where that originated, but you see it in a lot of articles. The reasoning behind it is that all the ligaments and tendons in your knee are so close to the surface that they are easily impacted by the cold and become more susceptible to injury.
The bottom line for me is that I would prefer to be warm than cold, so I tend to overdress when the temps are "between" cold and hot.
This comes from the sports medicine people so I am inclined to think that it is a good idea. But for short durations it is probably not so critical.
Your body secretes a fluid in the joint for lubrication called bursa. When it is cold this process does not work as well so during extensive exercise in the cold the joint will actually wear out faster because it gets less lubrication. There are not a lot of muscles surrounding the knee joint to keep it warm. Most of the muscle mass is above or below the knee so it may be more vulnerable to the cold.