In the changing landscape of global health, new challenges continuously emerge and new ways of addressing them are needed. There are huge discrepancies between health care services in high- and low-income countries, and those countries' ability to deal with these health challenges. Physical inactivity is recognized as a growing and serious problem for global health. Physical therapy - an allied health profession primarily interested in function and movement of the human body - is well-established and -recognized in most high-income countries. In low- and middle-income countries, however, physical therapists are either severely limited in numbers and inaccessible to most, or services are established largely outside of national health systems. Yet in these countries, physical therapists can have a major role to play from promotion and prevention to habilitation and rehabilitation. Using physical activity as its underpinning approach, there are clear gaps to fill within the spheres of non-communicable disease, maternal and child health, aging populations, HIV/AIDS, musculoskeletal disorders and injuries, and mental health, to name a few. Thus in this discussion paper we propose that, as a component of collaborative interdisciplinary care and with contextually adapted and locally rooted services, physical therapy is an important health profession for health systems in low-income countries.