No no no! Ok, let me explain.
Speed waxing covers the general body of the male and female. Everything apart from the intimate areas.
Once you are qualified in general body waxing or speed waxing (that's just a term), then you can wax a back, legs etc etc. It's all of the general body.
However, to wax a a male and female intimate area, you need to get trained to be insured. It's an odd thing as most insurers say that if you can wax a leg, that you can wax every part of the body, however, they are all asking for certificates, so it's a bit confusing.
So back to your question:-
If you have done my Speed waxing or you have a certificate from anyone else in basic body waxing, you are covered to wax a mans back.
NOTE: The term Back, Sac & Crack is very misleading as it doesn't mean the full back and shoulders; it's just the small of the back (the area above the coccyx/tailbone).
HTH's x