Not one week goes by w/o someone showing up w/ their saddle too low?

A joint is a structure of peculiar delicacy, and one that responds only too readily to injury. Man was not originally deigned to stand upright, and so it is natural that the weigh-bearing joints, in particular those of the lower limbs and vertebral column should be among the principal sufferers. Add gravity (hill work)and that changes everything as the loads increase.

You can buy the best tires in the world, but if the front end of the car is out of alignment they will wear out quicker. Now think of the chronic wear on the knees.

Rather than having a totally destructive effect on joints, it seems more likely that since we are semi-weight bearing while on the saddle moderate, regular exercise is beneficial. But the truth is anything over moderate can cause you problems.

Use the idea of hanging a plumb line from you knee and you are sure to get things off. For starters, no two people have the same knee cap size/thickness, nor foot size. What about the different sizes of upper & lower legs? Even the inclination and diameter of the pelvis can affect the "human link" chain.

Maybe that is why we consider the hip shape and size as part of the fit. Not just the knee over the ball of the foot.

We can't tell you how many knee problems we seem to relieve from a too low saddle. We ask how did you find you saddle height? They always come back that they used a plumb line?

Even w/ the perfect set up you still need to know how to pedal.