Create Control of the Pole Vector

1.Create Nurbs Primitves>circle,set Radius to1.5 in the inputs of the Channels Box.

2.Rename the circle to "L_leg_poleCtrl"

3.Hold "v"key and Move the Contrl  to joints of  the L_hip

and then move a little from body,keep alignment

4.Choose Edit>Delete All By Type>Non-Deformer History

5.Modify>Freeze Transformation

6.Select L_leg_poleCtrl then select L leg ikhandle

7.Chosse Constrain>Pole Vector(Note that  L leg ikhandle is no keyframe in timeline)

8.Finish