This paper outlines a method for eliminating a problem that occurs when motion capture data fails to reproduce the footplants of a character and artifacts called footskates occur.  A footskate appears when the feet of a character move during a period when the feet should remain in a fixed position, also known as a footplant.  The algorithm devised in this paper attempts to solve this problem by precisely enforcing footplant constraints without causing additional visual artifacts.  

Motions are processed sequentially, and the algorithm uses the information from nearby frames to maintain continuity.  Once the position of the ankle has been calculated so that it satisfies the plant constraints, the algorithm allows for the length of the leg to be adjusted to avoid sharp changes in orientation.

Other work has been done to automatically identify fotplant constraints, including methods that rely on analytic inverse kinematics algorithms.