Machines ARE safer strictly with respect to sitting in the machine. Outside the machine, I have personal experience that your shoulder, leg, and arm muscles mi

Machines ARE safer strictly with respect to sitting in the machine. Outside the machine, I have personal experience that your shoulder, leg, and arm muscles might be able to trivially lift a mere concrete block but your back muscles (luckily in my case not a ligament) were not strengthened by the machine to a similar level leading to quite a bit of pain and damage. Which is the short version of life experiences explaining why I'll probably never go back to machines in the future. Given an infinite number of machines, presumably one for every muscle or so, and an infinite amount of knowledge such that you strengthen your back to always be 5% stronger than your arms or whatever, then machines would be safer than free weights. Of course given spherical cows I'd have the same level of knowledge and safety of free weights. You certainly could hurt your back without any relationship to strength training at all. Or even hurt yourself after freeweights. But it is more likely after machine work. There is also a practical matter of scale. Lets be realistic. A really bad day of lifting won't be much worse than naturally happens to fat couch potatoes every day, so its no really big deal. On the other hand a "really bad day" of bicycling means getting turned into grease under the wheels of a truck, or a "really bad day" of hiking means hunters find your body after a couple months. Its not in practice a serious concern, compared to other human activities. Not that opposition to machines is some kind of amish / historical re-enactor philosophical opposition. Not using a squat rack when squatting is probably an excellent way to hurt yourself. Someone should invent a machine or technique to do bench presses safely while alone.