Well, in short, yes. Here's the question getting asked and answered from Cressey on his blog...Stephen Johnson wrote: Does that mean that leg curls are counterproductive in training the hamstrings? I've done stability ball leg curls, but I can't do them with more than bodyweight. And without an apparatus, glute ham raises are a bit of a challenge.
http://ericcressey.blogspot.com/2007/03 ... nkers.html
(i just noticed the title of that blog post - quite bizarre / extreme!)
The only benefit in them is hypertrophy - a lot of BB's swear by them. The glutes and hams should work together so it's counterproductive in that sense. But really, if you've got you're big money exercises covered, which i know obviously you do, then leg curls alone aren't going to do you any harm.
The problem really is when you take someone with weak glutes, in anterior tilt, and therefore the hammies are basically the only muscles left to extend the hips. So leg curls just enforce the imbalance of weak glutes and overactive hamstrings. So it's not a case of "if you do leg curls you will get injured!". It's more a case of 'if you have issues, then you go and do leg curls regularly, then you'll make those issues worse."
In terms of strength, I believe they have no carryover at all. Certainly not in my experience and not as far as i've read. But obviously not everyone cares about that.
For GHR's - do you have access to a lat pull down? YOu can kneel on that with your heels under the pads, facing away from it, and lower yourself that way. Quite brutal at first but limited in the long run. You just need to find someting to hook you're heels under.
With stability ball leg curls, all you can really do is go to the single leg version to make it harder. I tend to do these type of exercises after DL's, box squats and the likes so the hammies are just about done...Makes these exercises harder...