Let me see if I can clarify as I do not pay as much attention to the details of the head forms because I do not understand all that is entailed in the whole thing. But I do my best in the meetings to understand the main points. The head forms VT uses are football head forms. Therefore the head form is not attached tot he head the same and is modified to do so.
The IE and HECC and CSA all use a standardized head form for hockey helmets. They all fit and are attached the same way.
However, VT uses a modified neck form that NOBODY else uses to attempt to simulate rotational impacts. The neck form used is made in a way that is not the way a hockey player would take a hit and the end result would be squed, from an actual real-life playing situation. My understanding is all the hockey helmet testing programs have been vigorously working over the last 4 years to come up with a test for rotational impacts and the present hockey helmet using the head form used in testing now. It's not as simple as sticking a head form on a neck form and calling the test results facts. So far all the testing has given non-consistant data and hence why there is no set program yet for rotational impact testing.