IK is suppose to help this but when importing a BVH or using the Walk desiginer to create initial movement. The IK means absolutely nothing. Imean the feet will not lock down. I have tried to keeframe the foot so that it does stay put uppon impact but always with poor results. I'll take a look at the hip z axis but again The BVH file seems to change things. I'll double check that hip. Acceleration would occur as the foot is leaving the ground. Deceleration would occur just after the foot passes the top of the arc of the foots path and then continue to a brief stopping point when it actually hits the ground before beginning to accelerate again. JanP