Compensates for gimbal locking effects by unrolling rotations. Unroll Rotations is designed to clean motion capture data that contains large rotations which cause flipping or shaking in animations. 
Unroll rotations filter A. Original curves B. Unroll Rotations applied
When you select the Unroll Rotations filter in the Filters window, you can set the following parameters:
Quality
Lets you manipulate the algorithm that affects the path of rotation curves. The default value (.25) concentrates on the Y curve path. Tweak the Quality value to manipulate the path of the X, Y, and Z rotation curves.
Path
Select Path to enable the Quality field. When Path is disabled, the Unroll Rotations filter searches for and cleans sudden jumps in the Y rotation curves.