When you look more into ergonomics a lot of the information that they use can be directed towards what happens in the weight room or with fitness programs. Once of the big items that we want to look at is the concept of levers. When we lift weights, our body is utilizing levers to lift that resistance. First off, a lever is a rigid bar that rotates around a fixed point and we are going to be using anatomical levers.
These anatomical levers can be classified into three distinct categories and they are 1st class, 2nd class and 3rd class levers. We are not going to get into the technical details of each lever, but I wanted to mention them so you know. The one thing about these different classes of levers is that they all consist of the same basic components and they are: Fulcrum or Axis, an applied force, an effort arm (EA), a resistance force (RF), and the RA, which is the distance from the fulcrum to the point of resistance.
This is important to know when you just want to lift basic objects around the house. A quick calculation you can do is that if you are going to pick of a 50lb object from the ground and lets say it is 10 inches from the object to your stomach, you are putting 500 pounds of pressure on that part of your vertebrae. That is why you always want to bend your knees when you pick up an object and bring it as close to your mid-section as possible, so there is not too much pressure on your lower back.