I found that there are five components in knee and ankle reaction forces in my ChartFX1, I think there should be three, and have no idea about why five components? Could you tell me how this happen?

Hi,

In principle a joint has 6 degrees of fredom: 3 translations and 3 rotations. Ankle and knee are revolute joints, that means only one rotation is free. The remaining 5 DoF are locked and have a reaction force (or moment) each.

So the 5 component of the reaction forces you see in the chart are the 2 rotations and the 3 translations locked.

Best regards, Sylvain.

Thank you. so the first 3 are translations from x, y,z and then rotations, right?

1 Like

Yes, Exactly.