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One of the most common ways that people hurt their back is by simply bending over. A lot of times, it’s just bending over without even lifting anything heavy. There are probably two reasons for this. First, just bad form with bending. There is a misconception that you should bend with your knees not your back. Second, not bracing or activating the core muscles with bending. This can be especially true when someone is not actually picking up something heavy. A lot of people will intuitively brace when picking something up, but will not when they just bend over or are picking up something very light.
Let’s start with this idea of bending at your knees. This old saying is only partly true. You of course want to keep your spine as neutral as possible and this means you do want to bend your knees. However, the more correct saying would be to stick your butt out and bend at your hips. What I’m describing is called a hip hinge and as the name implies, you hinge at the hips. You can and should also bend your knees, but the focus shouldn’t be on the knees. If only focusing on the knees, there is a tendency to let them come too far forward which places stress on the knees. If you only focus on bending the knees, there is also a greater chance that you will end up rounding the back too much. By focusing on getting your butt back first, you will get more of the movement at the hips and naturally be more likely to keep the spine neutral.
The next idea is that the core should be braced when bending and especially lifting. Most people will automatically brace their core if lifting something heavy, but they might not when just bending. If you have a history of ‘throwing out your back’ with bending, it is important to always tighten up your core during bending. This tightening acts as a brace and supports the spine and pelvis so that unstable joints are less likely to get irritated. To make a brace you think of tightening your stomach muscles. For some people this is hard to do. Some cues are make yourself laugh and feel your stomach muscles naturally get tight. Another way is to purse your lips and do a quick/short burst of an outbreath. Again, feel your stomach muscles get tight with your fingers. This is the feeling that you want to recreate when bending.
Another consideration is to make sure that you don’t bend and twist. Lumbar spine flexion with rotation is one of the hardest things on the spine. Always keep objects directly in front of you and as close to your body as possible.