For decades we’ve been brainwashed to believe this poster.
There is in fact ongoing debate regarding the optimal posture during lifting. This study used motion analysis and EMG to evaluate 3 different lifting postures.
- Maximal extension (lordotic)
- Mid-range (flat-back)
- Fully flexed
They concluded that, “A flexed-back posture is associated with increased strength and efficiency of the back muscles compared to a lordotic posture.”
I know that one may argue and say, “But Bahram, many people hurt their back while bending to pick up a heavy box in a flexed posture.”
My counter-argument would be that they simply lifted an item that exceeded their tolerance and that the posture was not the issue. In fact, they need to lift using a flexed posture MORE often in order to become more resilient to lifting in a flexed posture.
One could argue that the avoidance of lifting with a flexed posture could place one at a greater risk of low back injury related to lifting.
Reference: Mawston G, et al Flexed lumbar spine postures are associated with greater strength and efficiency than lordotic postures during a maximal lift in pain-free individuals. Gait Posture. 2021 May;86:245-250.