In doing a PubMed search on the risk of injury from back squats (I was thinking humans), I came across the abstract of a study from Iran of resistance training in rats
and it's effect on ability to recover from heart attacks. (BTW, I'm not criticizing the use of rats for this study, which required removing the hearts from the bodies, and artificially inducing a heart attack. I'm not planning to volunteer for the human version of the study!) What I found funny, and a little interesting was this line in the abstract:
The rats were exercised in squat-training apparatus (12 repetitions/set, four sets/day and five days/week for 12 weeks).
Since the full-text article was available on line for free, I looked at it, hoping for an illustration of the "squat-training apparatus". I was just trying to picture how you can make lab rats do squats! I didn't find an illustration, but reading the article, I learned that the rats were in a cylinder where they pushed up on an overhead piston. So it was more of an overhead squat (TimD would have approved!). They lifted in response to an electrical stimulus applied to their tails. This implies interesting techniques that trainers could use to get reluctant clients to squat!
Then I got worried about the ability of the poor little guys to recover, given this brutal 4x12, 5 day-per-week training regimen. (I assume that the rats only trained 5 days a week because the lab assistants only worked 5 days a week.) The study didn't seem to concern itself with overtraining.
Finally, here is how the authors stated their conclusion:
We have shown that long-term resistance training confers a cardioprotective effect against myocardial infarction in a defined region subjected to ischemia-reperfusion.
They jumped from squats conferring cardioprotection in rats, to resistance training in general conferring cardioprotection in general, presumably any species! This is, BTW, a serious criticism. You can't just assume that findings in rats proves a similar affect in humans!
Next time I hear anyone criticizing squats, I'll just tell them that some guys in Iran proved that if I do squats, any heart attacks I have in the future will be smaller than they would be otherwise. So KEEP SQUATTING!