What type of movement is "spontaneous movement" if it isnt reflex movement and it isnt purposive movement?
Although I can't read the original article in Czech, from their abstract it is clear that all they mean in differentiating spontaneous versus induced movement is whether the experimenter manipulated the uterus to induce a movement. Movements they observe could still be reflexive, they make no distinction of the type of movement (and do not intend do) except indicating whether the movement was purposefully caused by the experimenter.