Ano
Hall of Fame
Equally Ano, I bet you yourself don't subject yourself to leg extensions or curls (I think you've said as much before)! When I was training other people, I'd never recommend them either, and I would certainly never do them myself....
For the record - for the sake of others, both the Fitness Association I trained at, and my Physio (a highly experienced sports physio) also are collectively against extensions and curls.
There's so many other ways to work legs, and anyways: when there's two options, a machine or a free-weight, ALWAYS choose the free-weight
If every trainers agree with this one, I would die a happy man.
I've been in some gyms where I see trainers use nothing but machines with their clients under the assumption that doing so is safer.
Listen, any movement or exercise can be dangerous if done with improper form and with a load you can't handle, regardless of whether or not you're using a machine or free-weights.
However, it's rather presumptuous, not to mention foolish, to proclaim that machines are inherently safer than their free-weight/compound counterparts.
And yes, I will never do leg extensions and leg curls myself.