The new model presented in this edition - The Integrated Systems Model and the Clinical Puzzle - co-developed by Diane Lee & Linda-Joy Lee, facilitates effective clinical reasoning, hypothesis development and prescriptive treatment. It is highly unlikely that there will ever be enough research evidence to mee the needs of a clinician who is faced with patients presenting with a wide and variable range of single and multiple impairments every day. Clinical expertise (knowing how to do the right thing at the right time) comes from disciplined, reflective practice and it is hoped that this text will help more clinicians become expert in this field.