Samuel
Level 2 Valued Member
There are definitely different acromion types, and the Type III acromion does increase risk of AC impingement. He is not wrong in that regard, and there are other guys who have spoken about this a bit (Eric Cressey and Mike Robertson come to mind - I'm sure there are plenty more).
However...
I don't believe there is clear evidence of the prevalence of the different types overall. I did a quick search and found this paper:
http://www.jshoulderelbow.org/article/S1058-2746%2801%2990918-8/abstract
"Only 4 (2%) of 200 shoulders were found to have a type III acromion by use of the standard subjective Bigliani classification. Eight (4%) acromion were found to be type III by the use of previously published objective criteria for acromial measurement. Our results show the type III acromion to be relatively rare in asymptomatic, young athletes, but the incidence of type III acromion in a general population of both young and older individuals is still not completely understood."
I don't have the time right now to do a more thorough search, but I would caution unfounded generalisations and leaping to conclusions. Think about all the potential structural or genetic differences that exist for predisposing people to certain things. Are we all going to live our lives assuming we have the 'worst' of everything and the highest risk of all problems? Of course not.
I, for one, will keep pressing until I have a real reason not to.
However...
I don't believe there is clear evidence of the prevalence of the different types overall. I did a quick search and found this paper:
http://www.jshoulderelbow.org/article/S1058-2746%2801%2990918-8/abstract
"Only 4 (2%) of 200 shoulders were found to have a type III acromion by use of the standard subjective Bigliani classification. Eight (4%) acromion were found to be type III by the use of previously published objective criteria for acromial measurement. Our results show the type III acromion to be relatively rare in asymptomatic, young athletes, but the incidence of type III acromion in a general population of both young and older individuals is still not completely understood."
I don't have the time right now to do a more thorough search, but I would caution unfounded generalisations and leaping to conclusions. Think about all the potential structural or genetic differences that exist for predisposing people to certain things. Are we all going to live our lives assuming we have the 'worst' of everything and the highest risk of all problems? Of course not.
I, for one, will keep pressing until I have a real reason not to.