A person may choose to walk, whereas a tremor or involuntary movement can occur without such a choice. Both movements are created, but their relation to voluntary agency differs. Walking is directed by an aim; an involuntary tremor is not acquired in the same manner.
This distinction underlies moral responsibility. A movement occurring without meaningful choice cannot automatically be treated like an act performed with intention, capacity, and choice.
Preserving the difference between voluntary and compelled movement is essential if belief in divine creation is not to be confused with a theory that erases human action altogether.