1. Multifidus and Paraspinal Muscle Group Cross-Sectional Areas of Patients With Low Back Pain and Control Patients: A Systematic Review With a Focus on Blinding by Maryse Fortin, and Luciana Gazzi Macedo ptjournal Volume 93(7):873-888 June 30, 2013 © 2013 American Physical Therapy Association

2. Flowchart of systematic review inclusion and exclusion of case-control and symptomatic/asymptomatic studies. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

3. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

4. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

5. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

6. Mean differences and 95% confidence intervals (95% CIs) of blinded and unblinded studies evaluating multifidus muscle cross-sectional area (in square centimeters) at (A) L4 and (B) L5 between patients with chronic low back pain (LBP) and control patients. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

7. Mean differences and 95% confidence intervals (95% CIs) of blinded and unblinded studies evaluating paraspinal muscle group cross-sectional area (in square centimeters) at L4–L5 or lower L4 between patients with chronic low back pain (LBP) and control patients. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

8. Mean differences and 95% confidence intervals (95% CIs) of blinded and unblinded studies evaluating paraspinal muscle group cross-sectional area ratio at L4–L5 or lower L4 between patients with chronic low back pain (LBP) control and control patients. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

9. Mean differences and 95% confidence intervals (95% CIs) for symptomatic/asymptomatic studies comparing (A) multifidus muscle cross-sectional area (CSA) (in square centimeters) between sides in patients with acute low back pain (LBP) at the pathologic spinal level, (B) multifidus muscle CSA or functional CSA (in square centimeters) between sides in patients with chronic LBP at level below lumbar pathology, and (C) multifidus muscle CSA or functional CSA (in square centimeters) between sides in patients with chronic LBP at the pathologic spinal level. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

10. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association

11. Maryse Fortin, and Luciana Gazzi Macedo PHYS THER 2013;93:873-888 © 2013 American Physical Therapy Association