I am a zealot on proper technique on tackling.
So much that I would teach how to tackle WITHOUT a helmet FIRST.
Second; The neck muscles are some of the easiest to build up. 4 way exercises with a towel and your partners knee for left/right and up/down sets of 8-10 seconds per rep is an easy way to increase neck strength/size to reduce whip lash and 'stingers' from improper tech.
Ducking your head instead of looking for your impact point and then sliding your head to the side is a sure fire way to a neck/head injury.
IT DISGUSTS me to see these chickenpoop DB's trying for a "kill' shot on REC over the middle. Using the helmet for a weapon should be automatic expulsion for the game and next, second offense add a game, third you're GAWN for the season.
Riddell, I remember when our high school had their rep come around and measure everyone for the new helmet. (1960's) The helmet order came in and my helmet would NOT fit. Dad, was my Head Coach, was sure that it was MY fault and tried to jam that thing onto my head, but it would NOT fit.
The rep came back and remeasured, my head had grown as I had had a growth spurt from 5' 10" and 150 to 6' 4" and 195. So Dad forgave me as he had been worried that I would be "Kirk" sized (my Mom's family were all wee Scots.) and was happy that I had grown.
Csonka was getting bad headaches in Miami his rookie year and the Doc's were clueless. The trainer saw his forehead and the bruises and swelling. "Larry does your helmet fit ? It looks tight."
Larry said it was the biggest helmet the team had in stock. Trainer called Syracuse and had a manager fly the Syracuse helmet (it was a special order from Riddell) to Miami. Repainted the helmet fish colors and that was the helmet he used his entire NFL career, took it with him and had it repainted as necessary.