For example, parkinsonism, such as what you are asking, has a resting
tremor that is termed “pill-rolling”
tremor. The
tremor is typically one sided initially. Other types of tremors include essential tremor (which is a tremor with many different postures/actions), orthostatic tremor, enhance physiologic tremor, etc.
Everyone has a tremor but for most, it is not noticeable unless there is stress, caffeine, anxiety. This is the enhanced physiological tremor.