Lack of the training led to the accident

I hurt my back when I was lifring the boxes. The weight of the box which I was supposed to lift was about 25-30 kg. I was aware how heavy it is as I was lifting this kind of boxes all the time in my job and it was one of my duties. The only one, but at the same time  very important difference is the fact that the box was placed. It was on the pallet  but under the shelf which was assembled on the high about 1 m  over the floor. I had to go under the shelf  and work in very uncomfortable position. I couldn't use my legs in order to lift it properly. That was the main reason why this seemingly action become very difficult and affected my back. The force was concentrated on my back instead of being dissolved evenly. There is a rule how to lift heavy objects in order o avoid congestion: the back should be straight and the legs should seize the weight. It was impossible to aply this rule in that position. To my mind the boxes which are placed under the shelf should not be there because it may lead to another accident like mine. Furthermore, I was thought about the mentioned rule only on the training which was organized after my accident. There was no training when I started working there. I am sure that this kind of the training would help me to avoid the situation in whih I became injured. How to claim? I feel that it was a negligance and I should get some money for it.