Occupational therapy practitioners use their knowledge of the transactional relationship among the person, his or her engagement in valuable occupations, and the context to design occupation-based intervention plans that facilitate change or growth in client factors (body functions, body structures, values, beliefs, and spirituality) and skills (motor, process, and social interaction) needed for successful participation. Over the course of the physical therapist's career, scope of practice evolves based on considerations including, but not limited to, societal needs; progressive professional development activities of the physical therapist; modifications to jurisdictional laws and regulations; advancements in knowledge, research, clinical skills, and technology; and the evolving health delivery system.