I am starting to get concerned about the compressive and shear forces acting on the lumbar spine during the SLS. Is anyone able to maintain a neutral lumbar spine while doing this? I imagine it would take excellent hip ROM and flexible hamstrings.
Single leg squat and lumbar flexion
Started by Shnordle, May 20, 2014 · 11 Replies · 3,781 Views
Really, you mentioned this about the arch too? Don't exercise you may very hurt.
I imagine, that unless you have a pre-existing back condition, it shouldn't be a problem because you are not bearing load on the spine, you're just bending it a little.
Normal human movement involves all sort of arching and bending of the spine.
The lumbar spine is meant to flex and the load with the SLS is minimal. Just as it is ok to flex the spine to pick things up. Many health professionals will tell you otherwise. I was one of them until I started this program. I had the same concerns as you, but once I got deeper into this program I realised my preconceived ideas were wrong.
once you have a strong jefferson curl you do not have problem here.
howens said:Really, you mentioned this about the arch too? Don't exercise you may very hurt.
I am just voicing some concerns and looking for clarification. I am not saying that these exercises are detrimental or dangerous. I have only recently learned about the biomechanics involved for a lot of these exercises, so I was curious what people knew about them. Just trying to be safe!
Thanks for the feedback guys!
It's my bad. I'm sorry, I was edgy this morning and it got the best of me.
Mark Collins said:The lumbar spine is meant to flex and the load with the SLS is minimal. Just as it is ok to flex the spine to pick things up. Many health professionals will tell you otherwise. I was one of them until I started this program. I had the same concerns as you, but once I got deeper into this program I realised my preconceived ideas were wrong.
It is interesting how a lot of what I am learning here is contrasting what I am learning in Physiotherapy. I suppose this is where 1 on 1 coaching can be that much more beneficial. I am just wanting to iron out all these kinks so that I actually am achieving mastery before I move on to the next stage of exercises. Definitely learning a lot!
howens said:It's my bad. I'm sorry, I was edgy this morning and it got the best of me.
No worries mate! A lot of this stuff is just challenging what I am being taught 
SAID principle applies strongly here. (Specific Adaptation to Imposed Demands)
If you progressively and intelligently load the spine in a rounded position, your body will adapt. I'm not sure how far this can be taken. As with anything, the problem comes when you are completely unprepared and approach something with no body awareness, and too much intensity and volume.
Just look at this profession strongmen pick up a 558 lb (254 kg) atlas stone (video here). His entire spine is FLEXED, and then he extends it under MASSIVE load.
I don't think loading a flexed spine is inherently a problem. The problem is being dumb about how you approach it, and not using intelligent progressions, volume, and intensity.
Justin Goodhart said:Just look at this profession strongmen pick up a 558 lb (254 kg) atlas stone (video here). His entire spine is FLEXED, and then he extends it under MASSIVE load.
Although, to be fair, he does try to keep his lumbar spine neutral...
OP, don't worry about sheer/compressive forces when it comes to unweighted squats. The whole reason they are a problem with weighted squats (or deadlifts) is because the bar is connected to the top of your body, so your spine has to transmit power from your legs. With an unweighted squat, you don't really have to transmit power anywhere except evenly throughout everything above the hips.
no compression, or almost the same as you would experience standing. shear is minimal because although you are flexing you are not bending over much and certainly not picking anything up. shearing forces work on the spine when you deadlift or to a lesser extent squat depending on how perpendicular your trunk is, less perpendicular more shear.
I have injured my lumbar spine and right sacroiliac joint more times than I care to remember, a couple serious enough to keep me in bed for a week and out of the weight room for a few months. SLS has been excellent in rehabilitation bc it works each leg separately and works balance and stabilization much more extensively than a weighted squat.
not handing out any lifting advice but one of my injuries resulted from trying to keep a neutral spine while deadlifting.