Small back could be described with alternative words such as "petite back", "compact back", "dainty back", or "slender back". To further emphasize the small size of one's back, other synonyms could include "narrow back", "restricted back", "modest back", or "limited back". Depending on the context, alternatives such as "delicate back", "tiny back", or "diminutive back" may be more suitable. Describing one's back in this way may be helpful in situations such as clothing shopping or when discussing body measurements with a healthcare provider.