This is s fairly common issue with IMA. You loose lead arm support and exaggerate the trail arm push and the club head goes through impact without rotating. For me this most often happened with driver and with short wedge shots. Because of it I invented a drill (2.5
) ala the Impact Backwards drills just to practice trail arm extension causing rotation of the lead arm. I actually use this on occasion for short chips and pitches. Here
is more detail from one of the first posts I made about this. If you like diagrams more than words there is a diagram of what I mean here
Note that this rotation is what SHOULD happen if you return to impact position at impact which you should do in the Impact Backwards drills (and with respect to club rotation, for swings as well). Your body and your arms should return to the correct impact position that you set at address and that position had a square club face (for a straight shot).