IRCT2016081921459N3 IRCT 2017-06-19 Iran University of Medical Sciences Effect of exercise therapy on thickness change of lower limb musclles Evaluation and comparison of trunk stabilization and lower limb abductor muscles exercises impacts on thickness changes of the selected global and local lumbar and lower limb muscles and its association with the pain intensity and disability in women with chronic low back pa 2017-06-22 anticipated 60 Complete https://irct.ir/trial/18800 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment. N/A Chronic low back pain. Intervention 1: Routine physiotherapy treatment involves the use of device-TENS with frequency 80-100 Hz and surface heat and stabilization exercises, including muscle contraction multifidus and transverse abdomen in diferent positions ( supine, lateral positions and quadrapd position. Intervention 2: Routine physical therapy treatment involves the use of device-TENS with frequency 80-100 Hz and surface heat plus abductor muscle strengthening exercises.