I have no problems putting these on one handed. If they don't fit right out of the box, you can bend the hook a little, it is meant to be shaped but I had no problem right out of the box.
I absolutely love these headphones. I look at them as the perfect runner's head phones. No more wires bouncing on the back of my neck while I run. I have been using them in the gym and home too. For those who say it isn't loud enough, been able to get a good enough seal and loud enough to drown out the wife nagging me.