It's possible to calculate probable lifting capabilities and percentage of load which can be handled easily at fingertip point, the 100 percent area, and positions to avoid when lifting loads. The lifting ability decreases rapidly when the height of the lift increases above the optimum lift height.
The lifting ability falls off more slowly as the lift height decreases below the optimum. Near the floor, the ability is about 75 percent of the optimum. Before lifting an object, size up the load. Can you handle it by yourself? Does it have any sharp edges, nails, or slivers? Is the object slippery, hard to handle, or grip?
Test lift the load first to see if you can lift it. Mentally lift the load first. Don't let the size of the contents of the load fool you. For example, which is heavier, 32 pounds of lead or 32 pounds of feathers?
We know both are the same. However, the bulk of the feathers makes the load more awkward to lift, keep close to the body, and carry. Check the load you are going to lift and see if you should be wearing proper protection equipment such as hand protection, safety shoes, goggles or apron.
Before attempting a lift, make sure there is good footing by checking the condition of the floor. Is it slippery or wet? Are there objects that could cause you to trip? Be careful working on docks, walkways, and platforms.
To start the lift, the first thing to do is to make sure you have the proper foot position. Step up close to the load. Place your feet in a comfortable position on each side of the object. This provides a wide, stable support and helps maintain your balance when squatting down.
Some people prefer to place one foot ahead of the other, but any method is good as long as you are comfortable and balanced. Crouch down and keep your back feeling natural by maintaining the natural curves.
Bow in your lower back. This allows the vertebrae, discs, ligaments, and muscles to be in their normal positions. Extend your fingers and hands around the load using the full palm. Don't try to lift with just your fingers. They have very little power and strain will be placed on the forearm.
Bring the load close to your body and keep your arms and elbows tucked in. If you arms are held away from your body they will tire and put a load on your back. Hands should be on the opposite corners of the load.
Now when lifting the load, first raise your head then push up with your legs. Don't crouch down any further than you have to. Maintain those natural curves and know your physical limitations.
If the load is lifted the length of a forearm away from the body, 10 times more pressure is put on the lower back than if it were held close to the body, so hug your work. If the object is too heavy or awkward, don't feel embarrassed to ask for help. Don't try to be superhuman.