I think everyone is confusing the issue. There is a big difference between a collapsed arch and a pronated ankle. Pronation of the ankle can be caused by ankle mobility or weakness and does not have to be a byproduct of heavy lifting or a collapsed arch. If your ankles are rolling inward during heavy squats you should address that issue directly.
I do not like lifting with insoles or arch supports, or even shoes with arch supports, because of the pressure that the arch support puts on my foot during heavy lifting. Let's not forget that one of the big problems with a collapsed arch or pronated ankle is that you are changing the way loads are distributed on the foot. It has also been advocated by many people that training barefoot or in thin flat shoes helps to improve the foot by working the small muscles that would otherwise be obsolete because of the support and padding provided by orthotics or soles with arch support. But again, arch support or not, you can damage the foot by overworking or straining the small muscles of the foot.
To me this whole argument is very similar to the "grippers will give you carpal tunnel". The answer is yes, you can get carpal tunnel from grippers, but only if you train like an idiot. If you train correctly they are of significant benefit to hand/wrist health and function. The same can be said here and in many other cases. If you train improperly you can turn something beneficial into something damaging.
Now "Years of Heavy squatting" is similar to what Joe has mentioned above as Overuse without using precautions and It is the precaution which Kaizaad has suggested. Let us see what Eric has to say on this.
I think you are missing my point. It does not have to be overuse over a period of years. It could be days or weeks or months.
Harish, If your arch is collapsed wouldnt the pronation of foot occur? It is not unstable knee causing pronation of foot, it is collapsed arch causing pronation.
I disagree. You can have ankle pronation with a healthy arch.
I've noticed a trend of "waiting for Eric". Eric is not on retainer to answer everyone's questions and although he is a very smart and knowledgeable person, he's human and can't know the answer to everything. He does his best to address everything on the site, but it is more than enough work to keep the site going and produce content. Everyone should be researching and looking for information and discussing. The point of the forum is to discuss things. Eric did not do laboratory research on the risk of arch collapse due to the use of orthotics in exercise and he wasn't born with the answer. He had to work hard to get to where he is at. You don't get to that kind of knowledge level by having answers given, you have to do the leg work.