To avoid injury when you're putting an item down, proper technique involves:
a) positioning your hands so your fingers don't get caught under the load
b) placing the load in the center of the surface so it doesn't fall
c) keeping your back arched
d) lowering the item quickly, locking your knees so your back does the work

positioning your hands so your fingers don't get caught under the load  ( A )

Explanation:

To avoid injury injury while putting an item down it is important your place your self in a safe position and also your hands so that the load does not come down on you awkwardly.

so positioning your hands so your fingers don't get caught under the load is a very good technique while lowering the item quickly locking your knees so your back does the work is a very bad technique because this can lead to severe back injury and back pain. while placing the load in the center of the surface is a way of securing the item and not a technique been used by you to avoid injury.