What are the best exercises 16 months post spinal cord stimulator implant surgery? Besides a recumbent bike, is Pilates an option? Weak core.

An approach. I prefer starting with a physical therapist working in a warm water pool, and doing gentle exercises initially. Later, one could start some core exercises working on back and abdominal musculature. At some point, an experienced personal trainer should get involved. The equipment is not the key ingredient, instead, the human support and interactional education.
Spinal surgery. Six weeks after implantation of a spinal cord stimulator, the device will be encased in scar tissue and will not migrate with exercise. In general, low impact exercises such as pilates are excellent to build core strength.