Well, definately had to stop at this post!! What an intriguing title!!
Humping pressure on hips...not sure...
BUT, you do realize that humping can have other implications!!
Humping can be due to excitability. It could be due to a dominance issue. It could be due to a female in heat.
Personally, we do not allow humping with our dogs and yes, two boys will do the same because it is a dominance issue. We don't allow it because, a dog is a dog and will do it to small humans if they are led to believe this behavior is alright. Small humans to dogs are meerly another pup to be dominated.
So rather than hip issues...think about what is causing it!!! Trust me, we have had our days with our own Newfs, and you don't want a big dog thinking it can hump on a whim!!!
Luvmenewfs