'shoulder-strapped' originates from the combination of 'shoulder' and 'strap,' where 'shoulder' refers to the part of the body and 'strap' refers to a strip of material used to fasten or secure something.

'shoulder' and 'strap' have been used in English since the Middle Ages, and their combination into 'shoulder-strapped' is a modern English formation.

Initially, it meant 'having straps over the shoulders,' and this meaning has largely remained the same in modern usage.