The following are the basic options in the Muscle Spline Deformer window:

Name

Enter a unique name not used by any Muscle Spline or Muscle Spline deformers. The rig nodes created use this name.

Num Controls

Sets how many controls are used by the spline and deformer. You must have at least two, one for the start and one for the end of the spline.

Type

Lets you select the shape of the spline controls.

Make Muscle Object

If checked, the object is also converted to have a Muscle Object shape node so that it can be connected to the Muscle skin deformer.

Setup Muscle Spline Deformer

Applies a deformer to the selected object with the provided settings.