### Summary
This paper analyzes the correctness of linearly interpolated motions during the flight phases of motion, the contact phases, and the transitions between them.
### Problem
This paper examines the physical plausability of motions generated by a linear blend of input motions.
### Methods Used
This paper examines the mathematics of blended motions using simple rules for correctness based on Newtonian mechanics.
### Key Ideas
With a few modifications to the blending function, linearly blended motions can be obtained with a number of physically correct properties, including no extra forces, no footskating, correct friction, constant angular momentum, and continuity in center of mass velocity.