Arching at the top on back hyperextensions

Just curiosity
Any downside (medical/injury) to arch at the top when doing a back hyperextension or just useless?
Not only on this machine but on the GHR machine too
Like this one does here
[youtube]t0SRpgp5_rg[/youtube]

I’d advise against THAT much arching, some is fine but it should mostly be a hinge at the hips.

I would depend on what your intent is.
Excessive arching can be a negative thing for the spine/discs.
That being said bodybuilding wise a little extra arch adds to lumbar contraction to help build that deep valley look on the spinal erectors..
On the other hand if your doing them for strength purposes a neutral straight back is all you really need especially if you add weight like holding a plate.

[QUOTE=jaxqen;1644813913]
Any downside (medical/injury) to arch at the top when doing a back hyperextension or just useless?
[/QUOTE]

As Garage Rat posted, it depends on your intent.

I actually prefer rounding my back with 45 degree hypers, so the opposite of that arch. The intent when I perform 45 degree hypers is to pull using my hamstrings and glutes. I imagine it's almost like I'm performing a hip thrust into the machine, and the squeeze comes 100% from my posterior chain, not my lumbar erectors.

If I'm loading up with weight, my weight loaded will be limited if I throw in that extra backwards arch, and so my intended target of hamstrings and glutes would be minimized.

[youtube]jh45myksaEs[/youtube]

If your intent is to work your lumbar erectors, then sure, arching your back like that could have merit. Although personally, if I wanted to work my lumbar erectors, I would just perform explosive landmine rotations.

[youtube]mMP8fd2tRHk[/youtube]

It's fine....
Its a longer rom for your erectors ect.
Injurious? No.. * your body is designed to move.
A reverse hyper would be better than this in all likelyhood

Its just a different variation to the usual hip/ass/ham Hinge focused back extension


*unless you had a preexisting condition.