Abstract Healthcare practitioners (HCPs) from all backgrounds will encounter children who require and variably use orthoses to improve or maintain function. A basic understanding of why and when these are required is helpful, as it can allow a deeper discussion between HCPs, the family, child and carers. Orthotic interventions involve complex science and complex goal setting from birth to adulthood. This article presents a systematic ‘Inside-Out Approach’, incorporating all components of the International Classification of Functioning, Disability and Health and the International Standards Organisation objectives for orthotic interventions. This identifies the potential goals for bones and joints, muscles, motor control, motor learning, development of standing and walking, functioning, activities and participation, and prevention of pain, an indicator of quality of life. Achieving short and long term goals requires early intervention. The design and dosage, the duration and frequency the child needs to wear the orthosis, required to achieve goals will be determined by an understanding of natural history and prognosis, the goals set and the child's schedule of activities. Recent improved understanding of the contribution of the footwear, joint and segment alignments and segment proportion is discussed.