How many times have you heard this said? Well, in short it is a fact, it is likely better to use your legs than using your back to pick things up, especially if you don't usually lift heavy things. There is one issue with the theory around using your knees - are we using the right musculature from our waist down to lift? Or are we still overusing our back even though our knees are bent? Perhaps we need a movement assessment?
Our lower spines are strong and designed to flex back and forth freely. However, when flexed and under high load the soft discs in between our vertebrae can be pushed backwards which can result in what is called a disc protrusion. Bending our knees is a great way to initiate a straight back and puts less backward pressure on the discs, possibly reducing injury. Furthermore, do you lift heavy things usually? If not, your back may not have the capacity to handle this load - causing an overload of the tissues and therefore an injury.
With all of this said, it is totally OKAY to bend your spine day to day.
I have bent my knees and I am about to lift - now what?
Standing up with the load is now the important part, the knees are bent, the back is straight, and it will feel like you are pushing your buttocks back which is great because it is your buttocks that are going to help get you up.
Bending your knees has helped you to also bend at the hips (hip hinge) and this 'hopefully' causes the powerful muscle group called your gluteus maximus (buttocks) to help out with lifting.
Where lifting technique goes wrong
The knees are bent, everything looks great and you are ready to lift, here is where technique can go pear-shaped. The problem here lies in the fact that most of us have forgotten how to activate our gluteal muscles. We tend to come forward on our forefoot which causes the load to be distributed into our thigh muscles. We then tend to extend through our lower back to counter-balance. This will fatigue our lower back muscles making them sore and achy.
Tips on getting those gluteals to do the work
Distributing the weight down through your heels will help ignite those gluteals.
Consciously squeezing the gluteals before lifting will prime them to activate.
Turn the feet outwards slightly whilst ensuring the knees track over the second toe.
Still having trouble?
You may still find that lifting hurts your back. There could be an underlying cause that has not been diagnosed. In this case it is best to visit your physiotherapist to have a thorough movement assessment .