The investigators will recruit up to 20 volunteers with chronic, supra-sacral SCI. Following screening, eligible participants will enter 'Phase I', they will complete baseline outcome measures and then have the epidural spinal cord stimulator (eSCS) implanted with either percutaneous or paddle electrodes. Preoperative and intraoperative testing will determine exact location of electrodes. Mapping and optimisation of stimulation parameters will be performed simultaneously with urodynamic investigations of bladder function, and anorectal physiology investigations of bowel function. The acute effects of eSCS to suppress bladder overactivity, facilitate voiding, prevent unwanted reflex sphincter activity, and pelvic floor function will guide development of eSCS programmes for use at home. In 'Phase II', participants will use eSCS at home for 12-weeks. Participants will also be taught how to perform bladder and pelvic floor muscle training (PFMT) in combination with eSCS. Outcome measures assessing bladder, bowel, sexual function, quality of life, motor function and spasticity will be captured prior to and following the 12-week intervention, and at 3 and 6 month follow up.