Knees swinger

[dkerby]

I have a friend that starts the downswing with a big
knee swing/drive and as a result falls back to the right
side, hitting shots thin. For years he has done this and
had played in low 70s. Now 55 years old, he cannot do
it any more. No way the guy can get on the left side.

His head seems to be set correctly at address. I have
tried to focus on a stationary head to correct the head
from falling back in the downswing, but as Skywalker mentions
"Actually, the primary function of Knee Action - as with
Waist Bend - is to maintain a motionless head during the
stroke".

I have also tried downswing waggles, Correst axis tilt, Right shoulder on plane, hitting with right forearm takeaway, slow start in downswing, the Hogan Move of Trolio, single and double anchors, magic of the right forearm , but the guy just can't stop swing his knees.

Homer mentioned, "Besides, habits can be harder to to break than
to resuffle a little." Can anything be done to help my friend?