Just a quick suggestion: an easier way to do this would be to create a locator, and point and orient constrain it between the 2 feet. then just use the expression: pelvis_control.tx=center_locator.tx; // I don't think you want the ty controlled by the locator, but if you need to: pelvis_control.ty=(center_locator.ty + <offset>); // then you can use the adjust node to adjust the up/down movement of the pelvis. pelvis_control.tz=center_locator.tz; pelvis_control.ry=center_locator.ry; It might be a good idea to create a second control object for the pelvis that can be used as an adjustment node for the hips. The hierarchy should look like: Pelvis_control > Adjust_Pelvis_control > Pelvis Just a suggestion...take it or leave it. Good luck. c.