Motivation is nothing if not multifaceted, and every single element of it is bound up with communication, as is the whole process of management itself for that matter – no communication, no management.
The implications here are clear. Not only is motivation itself primarily executed through communication, but the precise form of that communication needs to be borne in mind and contributes directly to the effect achieved.
Perhaps the first thing to recognise is that sometimes the opportunity to motivate and do so successfully is dependent mostly on the way things are communicated. The following case, something I was involved in a while ago, reinforces this point.
Example: communications – big problem, small ...