Leg press hurting lower back?

[Lee]

Well I had a lower back injury that stemmed from many different things. I was talking to a guy at the gym today about it, and I mentioned that one of the reasons may have been squatting. He then told me that a lot of people actually hurt their back by doing leg press with both legs, because when you go deep, the pressure on your hips forces your back to arch. He then recommended that I continue squatting and try 1 legged leg presses after my squat session. Can anyone verify this? Or should I just give it a shot and see how it feels?

 

[bignate73]

it doesn't force you to lose your arch, it forces you to round your back. your hips tuck under and the pressure goes from your hips to whatever the next point of contact on the pad is...your lower back.

 

[Protobuilder]

I've heard that as well. With proper, smart form and adequate flexibility, I don't think back pain should be an issue on squats or leg presses. Any movement performed sloppily can create back pain. I think you could continue w/ two-legged leg presses if you want, but do what's necessary to avoid lower back rounding.

IMO, nothing's better for flexibility and strength than full range of motion squat variations (front, back, overhead).

 

[Lee]

well proto, i would have to use a much shorter ROM to avoid rounding my lower back. but i guess if thats what it takes.

 

[Protobuilder]

Hmmm . . . I guess it depends somewhat on how the machine is set up and on your flexibility. Can you sit down deep in a shoulder-width stance (like the catch position in a C&J or the rock bottom front squat position) w/out rounding your lower back? You probably ought to be able to sit down deep while keeping an arch, and that can be difficult to do at first but is definitely achievable with some practice. I’m speculating that if you can get that deep position, the leg press ROM should be a piece of cake. I’m no leg press expert though. LoL Maybe the angle and feet placement is closer to a PL style squat, with your hips winding up “behind” your ankles a good deal. In that case, stopping about halfway down (similar to a parallel PL squat) is probably best, as you just can’t sink a PL style squat deep while maintaining a back arch (or at least, most can’t just due to the mechanics of that squatting style).

Also, WTF are you doing bothering w/ leg presses anyway? They’re for the elderly or the injured. LoL

 

[stevius]

From what I remember the leg press involves quads, hams, hips and glutes. The function of the *back rest* is ... to rest the back. In other words the spinal erectors are barely involved in this movement, if at all.

There's no reason to think that the thighs are going to bend any better without hip rotatation in a seated position. In fact your legs are already parallel in the starting position (if you can get your knees to your chest without your spine going into a reverse arch you are very flexible indeed). As Bignate mentioned the leg press forces many people to round the back.

Therefore hip rotation is inevitable- due to the fact that the spinal erectors have no work to do muscle tearing is unlikely but if you take your knees to your chest not only is the back rounded but the hips are pushed forward. If, for example you lay on your back and bring your knees into your chest it's likely your hips will no longer be touching the floor. The same thing occurs on a leg press. As the hips are no longer touching the back rest they are not providing any leverage and so the stresses are transferred up the spine. The spinal erectors are in a mechanically weak position but are forced into taking over from the hips- this is not a good thing.

Anyway, in a nutshell, keep your hips firmly pressed against the back rest.

 

[Lee]

I always sit deep in the seat and hold the grips hard enough to keep my ass and hips planted. I bring my legs as far back as they can possibly go, no bouncing, just a clean full ROM rep. Maybe I should try shortening my ROM a bit and see how it goes.

 

[Island Son]

anything over 300 lbs in leg press put too much pressure on my lower back & spine, and I I had to keep a death grip to plant myself in the chair like you said. So i stopped using it 3 years ago and do only back squats now. It was a nice power feeling when going heavy but it's too much pressure.

 

[ProtienFiend]

how tall are you?

 

[al420]

You may want to put some additional padding behind your back - may be what the "how tall are you" question is leading too. I train w/ a guy thats 5'6" (he thinks he is 5'8" but that is a different story). He uses a pad from another machine - it only covers the lower back region - it helps him and he stacks the machine to it's max (28 plates) and reps it for 15+ reps and uses a full ROM (Dorian would cry). I have even seen him use an entire back piece from an old bench to get himself closer. They are certainly not the most versitle piece of machinery in the gym.