manual handling calculations
Out of interest, it is possible to produce calculations which show the approximate effect of holding a load either close to or far away from the body.
The twisting force on the body is a combination of force times distance and is known as torque. It may seem odd mixing up weight and distance but it is common in engineering. In the picture above on the left, a person is picking up a box at arms' length. The effect of the box weight and the weight of his upper body is shown as 2,100 ins/lbs. That's the measure of the twisting motion on his lumbar discs.
On the right hand picture the person has moved the load as close as possible to his body. The calculation is now shown as 480 ins/lbs...... virtually a quarter of the picture on the left.
Don't worry about the maths involved. It's only for illustration purposes.