Cool thanks Eric. Good read. I will be more carefull in the future. Only very light stretching in the lumbar region. The Torso twists I was doing are standing and dynamic. I can now see it was very silly.
The Windshield wipers I am talking about are either done with knees bent or legs fully extended. The legs are rotated from side to side while lying on your back.

Thanks MaRvO.