Electronics is the LEAST of your worries. You have torque/rotation requirements that you've not well defined and are required to be before you can advance to prototyping the electronics, the physics alone are difficult because of the high torque involved and safety issues.
One thing I can tell you is that a few AA's is not going to cut it, to do what you want would require modest power, at least if you wanted it to last more than about 60 seconds. If it's actually for a personal massager trust me you will also require heat, which is totally not practical with battery power, I would strongly suggest you start with a power wire. Nothing wrong with the idea, but before you go defining your absoulte requirements, please learn as much as you can about the practicalities from every aspect, as that's the only chance you have of succeeding.
At this stage it's techincally 'off topic' for the forusm, but there are plenty of people here that are knowledgable about general engineering topics as well, and it's going to lead to electronics as well, so a good place to start.