I've been doing these weighted. at first i would hold a plate like in the pic...

i've been doing these weighted. at first i would hold a plate like in the pic, but once i got to 20kg+ it became unwieldy. so now i let my arms hang vertically and just grip a plate in my hands. this means that i don't get to a 45 degree angle. should i stop doing this?

Yes- hold a barbell across your back instead

>it became unwieldy

So do lower weight until you get better control.

thanks, i'll try that.

how would i "get better control"? it's nothing to do with my strength.

Put a bar on your back and you'll die. Put the bar on the ground.

i already tried that, it shortens the ROM even more than what i've been doing.

Dumbells work well for me

Then you have must have a tiny bench or you're a giant.

Use a kettle ball or dumbbell if you need more than 20kg in a small size.

i'm not very tall so i can't set the bench very high

i tried dumbbells and kettlebells. the only way to get a 45 degree back angle is to bend my arms, which i'd rather not do.

put the bench on these things to raise it up.

Just do seated good mornings

raising the bench is a great idea. thanks.

np. but still don't put a bar on your back.

as long as it isn't on my neck, what's the problem?

Sometimes when I do these I get a sharp pain at the back of my knee. Any idea what could be causing that?

Hyperextension I'd guess

use kettle bell

Don't sweat it. Google a video of Aleksey Torokhity doing hypers with the bar. I see the article on allthings.gym but too lazy to link.

good video. my gym's bench is a piece of shit compared to that.