Low Back Pain has remain one of a common musculoskeletal disorder affecting 80% of people at some point in their lives..There is rarely any individual including the medical professional who has not suffered with low back pain.This pain if is severe has become the reason for disability for many patients.In the United States it is the most common cause of job-related disability, a leading contributor to missed work, and the second most common neurological ailment - only headache is more common.It can be either acute, subacute or chronic in duration. With conservative measures, the symptoms of low back pain typically show significant improvement within a few weeks from onset.There are various scales of disability for low back pain ,among them Roland And Morris Functional Disability Questionnaire is best used to know level of disability. Straight Leg Raise(SLR) is 'Diagnosis Directive' test done by almost every Doctor.The angle of SLR at which back pain,tingling,etc.starts play an important role to know the level of disability.If a Doctor knows the Angle of SLR for symptoms it can make diagnosis very simpler.This book gives correlation of SLR and Low Back Pain in terms of disability.