HB/LB squat and back safety

[exter]

I've seen that HB squats are more dangerous for the lower back than LB squats.
Why is that ?
In LB squats you have to lean forward more than in HB squats so that's more torque on the lower back.

[Roy]

I know that if you do the low bar cues like sitting back really far, and you have lots of forward lean...while you have the bar high up on the traps...that's tons of stress on your low back.

Think about the length of a lever increasing its power. The length is determined by the bar position, high or low. If it's in high bar position...the lever is longer. If it's in low bar position, it's shorter...closer to the pivot point (around your low back).

When you have more forward lean you do have more torque, but if you're in low bar the lever is also shorter so there's some balance there. I couldn't tell you the math to calculate which one is actually more torque, but in any case everyone's exact measurements are going to be different anyway.

But, if you have a lot of forward lean and you are in high bar...you will certainly increase your risk of back problems.

[exter]

Let's assume that the distance of the bar in low position from the lower back is 50 cm , and in the high bar position it is 54 cm.
The moment exerted by the bar in the low position is 50/54 = 0.93 as great as the moment exerted by the high bar.
So the lever is longer , yes , but that's only a 7% difference , quite low.
I'm sure the torque caused by leaning forward outweighs that 7% difference (+ high bar allows less weight thus less torque).
The best (regarding torque) would be low bar with minimal forward lean , but I guess sitting back is part of a properly performed low bar squat , and the bar will not be over the mid foot which will cause other problems (knees forward ...).
Still , I don't understand why a low bar squat is safer for the back than a high bar squat.

[Roy]

I think the distance between low bar and high bar might be more like 3-4 inches, not 4 cm. 4 cm just doesn't seem like a very low bar squat. That would still be on my traps.

But again, I couldn't tell you the math/physics of what difference that actually makes.

[Jamie J. Skibicki]

Both are safe if done correctly.

The high bar has greater POTENTIAL of low back issues since the bar is higher up and the affect of form degradations in increased.

[DV]

While I appreciate the theoretical analysis both here, and very much so in the book, I think it comes down to anthropometry and preference. The longer I workout, the longer I start subscribing to Pendlays vision: Just do whatever style suits you best.

I get Rips argument about working more muscle, but I think that in the grander scheme of things, it isn't the most important.

I currently use HB to ease the pressure on my elbows and shoulders. It annoys my knees and lower back/pelvis more than LB, but in sum is better for me at this point. Other people have the reverse happen - with LB annoying the lumbar more.

Also - using LB style (butt back, lots of forward lean) on the HB is no bueno for your lumbar, as Roy pointed out.

[DV]

The high bar has greater POTENTIAL of low back issues since the bar is higher up and the affect of form degradations in increased.

Very true and concise. As I discussed with TBone in another thread, my near max HB is alot uglier and more problematic than my near max LB squat.

[LudwigVan]

mu