We’re suppose to lift with our legs, but whats makes our back not suitable for it. Silly question i know.
In: Biology
Your back is just not built to carry weight. It’s a bunch of small bones to allow *movement*.
Your femur, on the other hand, is the largest bone in your body. It’s the absolute unit of bones, wrapped in the largest muscle group. Weight is what it does.
Further, any lifting you do with your back will require it to be out of position. Not in a nice straight line, but tilted so that it’s taking a side load which will have the effect of pulling all of those little bones out of alignment.
Always lift with your legs while keeping your spine aligned.
In short, the vast majority of people have stronger legs than they have backs. This is because are legs sole purpose is to support weight and move it around. Whereas your back, although it aids in the support of your body weight, is much less used to heavy weight, and more importantly has many more functions to do with the nervous system that make it so muscular growth in your back is harder to achieve than in your legs.
hurt your back once and you’ll know why. you’ll be stuck in excruciating pain and probably stuck in bed for a week and be on painkillers and still hurting for 2-3 weeks
Simple answer is, lifting with your back will cause back problems like hernias and such. Worst case scenario, you could literally end up paralyzed.
If you’re wondering why that’s the case, think about the muscles and bones in those areas. In the back, the whole structure is designed to be able to twist and turn in almost every direction. But the muscles and bones of the legs are built to bend the ankle, knee, and hip joints, mostly in one direction each. That means more muscle and bone strength are used to make those bends stronger, making lifting safer when using those muscles.
As a bonus, lifting with your legs a lot will make your butt look awesome.
Imagine a lever. When bending down to pick something up your torso becomes the lever with its rotary bit at your hips. As you might know, you have more force when working a longer lever. So by bending over you give the weight a greater lever. Similar to standing somewhere high and pulling a weight up on a rope, or having the same weight on the end of a long stick and trying to lift it to your height.
Mechanical advantage, aka leverage.
Your spine is a stack of interlocking bones with tide-pod-like discs inbetween, laced with muscles that can pull it straight.
When it’s nice and vertical, it can bear your weight easily. The force is evenly distributed on all the discs, and everyone’s happy.
But try a little experiment: try straight-arm lifting a heavy weight. Pick up two heavy bags of groceries and hold them close to your chest – it may be an effort, but it’s fairly manageable. Now try lifting them straight out to the side, in a T-pose. It’s *way* harder, and you’ll get fatigued in no time.
The forces involved are way higher, because your arms have all the leverage; they’re acting like a crowbar against the muscles of your shoulder. It’s like trying to close a door against the wind, but from the hinge side instead of the handle.
Now imagine doing that with the stack of jelly and bones that is your spine. Not only does the force required to pull it straight *vastly increase* the more it bends, but the forces on the bones themselves will pinch the fuck out of the squishy discs on the inside of the curve.
Your legs, on the other hand, have long strong bones with the muscles attached a significant way past the joints – a way better ‘gear ratio’, and the strain is taken by bone, not squishy cartilage.
Using your legs instead of your back is like lifting with a seesaw instead of a fishing rod.
As someone who has deadlifted 507 pounds, lifting something off the ground recruits a LOT of your muscles, mainly those of your back, core, ‘grip’ and legs. When you’re lifting something and your form is not correct (arched back for example), your body will compensate by recruiting the wrong muscles like your lower back, making you prime for injury.
This is why a cue for deadlifting is to ‘push’ down into the floor with your legs (to get them engaged more) and to actively pull back your upper back (traps) and contract the large muscle of the back (lats).
This doesn’t mean “don’t lift with your back”, it means “don’t lift *exclusively* with your back.”
I lift with my legs and wrecked my knees. Have had 3 failed total knee replacements. Back is ok though.
When you lift with your back, you put a lot of pressure on all the joints of your spine, causing damage.
Imagine it like a long stack of connected legos. If you put pressure on the middle (which represents bending and lifting) it is more likely to fall appart than if you have a smaller stack of blocks (think of a 1×10 stack as your back vs 2×4 stack as your legs).
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