The wider the base the support, the greater the stability
The lower the centre of gravity, the greater the stability
The equilibrium of an object is maintained as long as the line of the gravity passes through the base of its support
Facing the direction of movement prevents abnormal twisting of the spine
Dividing the activity between arms and legs reduces the risk of back injury
It is easier to push, pull or roll an object that it is to lift it
Movements should be smooth and coordinated rather than jerky
When friction is reduced between the object to be moved and the surface on which it is moved, less force is required to move it
Use the arm and leg muscles as much as possible, the back muscles as little as possible
Keep the work as close as possible to your body. It puts less strains on your legs, arms and back
Keep the work at comfortable height to avoid excessive bending at the waist
Keep your body in a good physical condition to reduce the chance of injury
Rest between periods of work promotes work endurance