The semantic role of manner adverbials is to describe the manner in which the action named by the verb is executed. In chronological order, the state portrayed by a manner adverbial starts before or, at least, simultaneously with the action. The state co-exists with the action during its process. Therefore, according to the conceptual structure of the Chinese, it is ordered prior to the verb it modifies.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.