The method obtains a signature (S) of a gesture produced in free space, e.g. for producing gesture recognition commands, by deriving at least one time-evolving signal representative of muscular activity involved in producing the gesture and determining at least one value of a parameter yielded by that signal.The method comprises the steps of: time dividing the time-evolving signal (14) into sub-frames (SF1, SF2, . . . ), and for at least one sub-frame: determining at least one parameter value (Psfi) yielded by the signal over at least a part of that sub-frame, and expressing said parameter value as a component of a vector (S) along a dimension thereof specifically allocated to that sub-frame (SFi), the resultant vector yielding the signature (S) of said gesture. The invention also relates to an apparatus producing such signatures and commands by gesture recognition.