Group A (Post Isometric Relaxation + Conventional Physiotherapy): This group will receive Muscle Energy Technique in addition to conventional physiotherapy for the treatment of erector spinae tightness. The treatment will be given on alternate days for four weeks with 8 - 10 repetitions of METs per session.

Range of motion will be measured by using universal standard goniometer.The goniometer comprises a body (rotation axis) with two arms attached to it, one being fixed and the other movable. The measurement of the ROM is performed by direct reading of the angle between the axis of rotation at the end of the active ROM of the movement assessed.

The Visual Analogue Scale (VAS) is an instrument for the measurement of subjective characteristics or attitudes that cannot be measured directly. It consists of a horizontal line with markings from 0 - 10 where "0" represents "no pain" and "10" represents "worst pain possible". The patient is asked to mark the number on the scale which best describes the level of his/her pain.

The Oswestry Low Back Pain Disability Questionnaire is designed to assess the level of functional limitations or disability in activities of daily living of the patients with acute or chronic low back pain. It gives subjective percentage score. The questionnaire consists of 10 questions each having 6 options. Each option carries from 0-5 marks in descending order. The total score of the questionnaire is 50 while the minimum score is 0. The patient is asked to fill the questionnaire and their level of disability is assessed by scoring in the end. Their attained score is divided by the total score i-e 50 and is then divided by 100 to get the percentage