What you need to know about back protectors
A back protector is a safety device all skiers should have, regardless of age. It's therefore important to find a back protector that fits your specific height and body shape. Back protectors protect against direct blows to the back but not to compression injuries such as a vertical impact (should you land on your head or flat after a big jump).
There are soft and hard back protectors. A general recommendation is to use a hard back protector for skiing off-piste and in parks, since it provides better protection against blows from sharp rocks, rails and boxes. The softer back protectors are suitable for skiers who stick to the groomed runs and wish to maintain maximum mobility.
It is very important that the back protector is not too big. You should be able to bend your head backwards, as far as you normally can, without the neck and head touching the back protector. A small back protector will not hurt or be uncomfortable like too big a one can. However, too small a back protector will not protect the entire back like a protector of the correct size will.
Be sure to carefully read the recommendations that each brand offers, and ask the staff at the store to help measure your back and advice you on the right size and brand for you.
Vest or pad
There are different forms of back protectors on the market. Which one you choose, whether a vest or a pad with straps, is up to you. Generally a vest stays snugly positioned but can be warm and sweaty. A pad might feel lighter and compromise mobility less.
Regardless of what you choose, make sure to ask a professional for help with finding the right size and fitting for you.