Here are some good books to start with as under:

Hertling, D. & Kessler, R. M. (1996) Management of Common Musculoskeletal Disorders:Physical Therapy Principles & Methods (3rd ed.) Philadelphia: JB Lippincott.

Kisner, C., & Colby, L. (2002). Therapeutic Exercise: Foundations and Techniques (4th ed.).Philadelphia: F. A. Davis.

Magee, D. J. (2002). Orthopaedic Physical Assessment (4th ed.). Philadelphia: W. B. Saunders.

Michlovitz, S.H. (1996). Thermal Agents in Rehabilitation (3rd ed.). Philadelphia: F A Davis &Company

O’Sullivan, S., & Schmitz, T. (2001). Physical Rehabilitation: Assessment and Treatment (4th ed.). Philadelphia: F. A. Davis.

Klippel, J.H. (ed.). (2001). Primer on Rheumatic Diseases (12th ed.). Atlanta: The Arthritis Foundation.

American College of Sports Medicine. (2006). ACSM’s guidelines for exercise testing and prescription (7th ed.). Philadelphia: Lippincott Williams & Wilkins.

Muscle Testing - Techniques of Manual Examination. 7th Edition By Hislop & Montgomery.

Tidy's Physiotherapy 13th Edition By Stuat Porter