Occupational therapists who use a 'top-down' approach begin developing a client's occupational profile to learn about a client's strengths and limitations and how the environment affects the client's occupational performance. Top-down approaches use a global perspective, and foundational performance factors, such as motor movement or range of motion, or activity demands, such as bodily structures, are only considered if needed. Occupational therapists who use this approach are often less concerned with a client's diagnosis and physical deficits and are more focused on how performance affects participation in occupations and life roles. The Canadian Model of Occupational Performance and Engagement is a commonly used model for occupational therapists using a top-down approach as it is occupation-centred and client-centred.

In contrast, a 'bottom-up' approach first considers foundational factors to understand a client's strengths and challenges. The focus is to understand which factors are causing poor participation in occupations and could include range of motion, muscle tone, strength, sensory processing, balance and coordination, or grip strength. A common belief of the bottom-up approach is that improving the performance of foundational factors will result in occupational performance gains. For example, a client practicing finger movements and manipulation would be expected to have improved writing ability.

The workplace setting often affects which approach an occupational therapist chooses to use. For example, in acute care, where hospital stays are short duration, it may be required to focus treatment on a particular movement, such as improving the range of motion of a limb. In contrast, a top-down approach is often used in a school setting when working with children with developmental disabilities.

Brown, T., & Chien, C. W. (2010). Top-down or bottom-up occupational therapy assessment: which way do we go?.