This document describes common terms related to forces and their effects as experienced by human bodies and their support surfaces. It provides further information on concepts around how these forces affect the human body's response to postural support systems, and particularly highlights the impact of the interface between tissues and postural support devices (PSD) on the maintenance of tissue integrity. It provides a general introduction to biomechanical concepts, phenomena, and vocabulary. This is intended to facilitate effective understanding and sharing of information between a range of disciplines/stakeholders involved in providing equipment to manage tissue integrity.

Representative stakeholders include people with a disability, occupational therapists, physical therapists, biomedical engineers, nurses, medical and para medical personnel, device manufacturers, and other professionals facilitating development, provision, and access to seating and mobility equipment.

This document does not provide detailed information that is currently available in physiological text books or scientific literature.