To Insert a Kink Point in a B-spline Curve

Select the Edit Kinks tool ( Modeling > Curves > Modify Curves .
Select the Insert Kink Points icon.
Select the B-spline curve.
Graphics display the proposed kink point on the curve. Its position is controlled by the pointer.
Enter a data point to place the kink point.
(Optional) Press <Ctrl+data point> to place more kink points.
Enter a data point to accept the insertion.

Inserting a Kink Point in a B-Spline Curve