Muscles help us move, enable us to interact with objects and the environment, and regulate critical internal functions. Unfortunately, they are susceptible to damage due to disease, ageing and trauma and are a central factor in diverse serious healthcare conditions including sarcopenia (age-related loss of muscle mass and function, where decline in muscle mass between 40 and 80 years ranges from 30% to 50%), stroke, muscular dystrophy, multiple sclerosis, soft-tissue cancers, venous ulceration, diabetes, degenerative myopathy and incontinence (between 3 and 6 million people in the UK, and 24% of older people, suffer from urinary incontinence). The emPower Transformative Healthcare Technologies 2050 programme will overcome the limitations of current wearable assistive technologies and regenerative medicine by deploying engineered robotic artificial muscular assistance inside the body, exactly where it is needed, to: 1. restore strength and control in mobility and manipulation in older people who have lost muscle strength and precision; and 2. restore controllable muscular capabilities for sufferers of trauma, stroke, incontinence and degenerative diseases. This will have significant knock-on effects on whole-body and mind health through increased confidence, independence and quality of life, massively reducing the healthcare burden and facilitating the return of sufferers to productive and fulfilling lives. The emPOWER artificial muscles will be engineered to bridge the gap between the nanoscale of fundamental energy transduction phenomena and the centimetre scale of bulk muscle action, and will be implantable using minimally invasive (including robot-assisted) surgery and advanced imaging to replace or supplement ailing muscles, providing short-term rehabilitation, long-term assistance or complete functional restoration as needed. To achieve our vision, we have brought together leading experts in soft robotics, regenerative medicine, bio-interfacing, smart structures, synthetic biology, polymer chemistry, self-assembly, bio-printing and tissue analysis, and clinical partners in neuro-rehabilitation, cardiovascular disease, head and neck surgery, urology, geriatrics and musculoskeletal medicine. Together, and with key industrial and social care partners, we will deliver the foundational technologies and first-stage proof-of-concept of the emPOWER artificial muscles within the five years of this transformative project, leading to major healthcare, economic and social impact to 2050 and beyond.