The Exercise Therapy: Principles and Practice is divided into two parts. The first part of the book explains principles of the exercises and the advance therapeutic approaches advocated to improve functional limitations and symptoms of various ailments. This part comprises twenty-one chapters. The second part of the book describes the various conditions and diseases practiced by the physical therapists across the globe. The conditions are described with the pathophysiology, clinical feature, assessment, physical tests and advance therapeutic exercises administered to the conditions. I am particularly excited by this third edition because it brings the book to another level in the journey to become the best comprehensive textbook for the learners as well as for the practitioners. Third edition is actually an extension of the first and second editions. The first biggest change in the third edition is manual muscle strength testing which previously in the first edition was covered briefly with the principles and basic concepts. The third edition of the book explains manual muscle testing with the full color presentation designed to maximize text and images quality, clarity and accuracy. This chapter covers the MMT of upper extremity, lower extremity and spine with emphasis on the position of the patient, position of therapist, substitution of the muscles and placement of the hands of the examiner for testing of the strength of the muscles and to minimize errors. I have tried my best to explain the deformities occur following individual muscle weakness or paralysis along with images and clinical manifestations. The second biggest change in this new edition is the addition of the goniometry. The chapter of goniometry describes range of motion, planes, axes, end feels, placement of arms of goniometer, position of the patient and examiner to minimize the errors in measuring range of motion. The third change in this edition is the introduction of some common conditions practiced by the physiotherapists worldwide such as lateral epicondylitis, carpal tunnel syndrome and deQuervain tenosynovitis. The whole arrangement makes reading a pleasure and time effective experience.