I happen to have a lot of training in spinal biomechanics and know the coupled motions of the lumbar spine very well. I learned the "counter-rotary phenomenon" as an un-named mechanism associated with connecting the lumbar spine and the pelvic motions--at that time it was prior to Gracovetsky's spinal engine theory. I understood it as a biomechanical mechanism based on anatomical structure and didn't really think of it as a phenomenon with the meaning of an exceptional, unusual, or abnormal, thing, or occurrence.