Lifting with a Flexed Spine - Harmful or beneficial?! 

Intra-disc pressure doesn't inherently cause pain. So, clinically, it is not relevant. Unless you have a severe herniation that causes pain each time they flex/twist, then flexion based movement should not be avoided in patients. You want them to get moving without fear and their muscles to strengthen/adapt. As he mentioned in the video, if flexion does cause pain, find other movement patterns in the meantime to avoid this

As long as your back is used to the lifting in that particular position, it may actually be benificial for your intervertebral discs, they need load to adapt. Lifting with a flexed back may be more demanding on the backstructures thus they need slower progression (you can use the Jefferson curl for example). And when we talking about lumbar flexion as as riskfactor for lumbar radiculopathy, I think it all comes down to the duration of the flexed position, as well as what the back is used to. As physiotutors showed in another video, physical exercise decrease the risk of lumbar radiculopathy, while prolonged flexed position at work or strenuous work increases the risk of it: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-VEdUolQ8UJ8.html

@@thierryz1369 as you mentioned is more demanding, simply because instead of using the whole structure in a natural way you're kind o putting extra load on purpose (on muscular activity). You're stronger when you don't feel the effort. This idea of flexing on purpose puts a lot of passive stress on the ligaments, joints and discs. I still can't see the interest on doing this approach.

@@henaken08 but more stress on ligaments discs etc (within there capabilities) aren’t inherently bad. Ofcourse you can lift heavier with only a moderate lumbar flexion instead of with a rounded back, but when it comes to treating fear of movement and cognitive restructuring, but also treating lumbar flexion intolerance I think something like the Jefferson curl could be a good option. It also adds specificity for some daily tasks like gardening or picking things up from the ground.

Added

That's very biomechanical reasoning and not proven in vivo

Valid point. But like he said flexion is inevitable to some degree. Would this not be true in every plane?

@@TheDirthound of course. But the idea that you will "adapt to anything" is nonsense, as is the implication of training everything the same way. You adapt in that you build defenses at some level to *better* accomplish a task, but to think that means you'll ever be 100% adapted and able to do whatever you want is bogus. As far as training, your body responds differently to frequency and volume with pressing movements vs squats. You don't train a barbell triceps extension the same way you'd train a cable pushdown--one is more compound, better suited to progressive weight, lower reps, the latter is much more isolated and better suited to higher reps, etc. Even with variation in load, what does your body automatically do when going from a light load in a squat, to a maximal one? It tightens and stiffens. It doesn't want excess movement, especially in the spine. Partly for efficiency, but I think for protection as well. As far as the position in which it stiffens, I'm not so hard and fast. Deadlifting with a flexed spine, neutral spine, whatever is fine, in my opinion, so long as the rigidity in that position remains relatively unchanged (besides incidental movement). That means your stability in such a position is good. Much more dangerous than a flexed (but rigid) spine, is one that is actively moving under load (what you can see with your eyes, not measurements). This says you're not strong enough to hold a position, and injury is more likely.

Which joints are you talking about when you say the forces are much higher?

@@acxezknightnite1377 i guess lumbar discs.

@@andrei1637 I would be inclined to disagree. The cartilaginous, encapsulated joints of the spine are the facet joints. The discs are reinforced by ligaments (anterior and posterior longitudinal) which hold them in position and resist anteroposterior shearing forces (which result from flex ion and extension of the spine). Where they weaken as part of the structural degenerative cascade, is when there are shearing forces with a lateral component, which discs are not equipped to withstand over time. In my line of work, it is always those lateral forces that result in lower back pain, and I therefore would be inclined to agree with the findings of these studies.

That's not how science works. If it is "proven by millions of observed cases" this would be the results in a lot of longitudinal studies but hey there is isn't. "Why take the Risk?" Because there IS EVIDENCE that being afraid to bend or "load" your spine or thinking that your spine is weak has a negative effect on function and pain. So buckle up your rounded backs and start lifting heavy.

@Alexander BlascoReyes Well, one of the roles of PT is to teach people how to properly use their body and I don't think people need any more strenghtening with a bent back if they do that everyday anyway. Lifting like that can not only get you (in my opinion) a faster "bad back" but you can also develop muscle cramps. The best way to strenghten your back, again in my opinion, is to do it with a big load and tension with a streight back. Speaking from experience, and a rather small pool number, all my acquaintances who had a back problem at the gym did a dead lift with an incorrect form. Now then, there were only 3 people who had some issues but they were at about maximum load. I don't know if it is as bad with normal day to day load. As for this study, I am looking forward for more studies like this to be able to compare.