1. Lee, A.Y., et al., Effects of abdominal hollowing during stair climbing on the activations of local trunk stabilizing muscles: a cross-sectional study. Annals of rehabilitation medicine, 2013. 37(6): p. 804-813.##
2. Parfrey, K., et al., Effect of head and limb orientation on trunk muscle activation during abdominal hollowing in chronic low back pain. BMC musculoskeletal disorders, 2014. 15(1): p. 1. ##
3. Been, E. and L. Kalichman, Lumbar lordosis. The Spine Journal, 2014. 14(1): p. 87-97. ##
4. Sorensen, C.J., et al., Is lumbar lordosis related to low back pain development during prolonged standing? Manual therapy, 2015. 20(4): p. 553-557. ##
5. Kim, H.-J., et al., Influences of trunk muscles on lumbar lordosis and sacral angle. European Spine Journal, 2006. 15(4): p. 409-414. ##
6. Cho, S.-H., et al., Comparison of contraction rates of abdominal muscles of chronic low back pain patients in different postures. Journal of physical therapy science, 2013. 25(8): p. 907-909. ##
7. O'Sullivan, P.B., L. Twomey, and G.T. Allison, Altered abdominal muscle recruitment in patients with chronic back pain following a specific exercise intervention. Journal of Orthopaedic & Sports Physical Therapy, 1998. 27(2): p. 114-124. ##
8. Oh, J.-S., et al., Effects of performing an abdominal drawing-in maneuver during prone hip extension exercises on hip and back extensor muscle activity and amount of anterior pelvic tilt. journal of orthopaedic & sports physical therapy, 2007. 37(6): p. 320-324. ##
9. Madokoro, S., H. Miaki, and T. Yamazaki, The effect of the abdominal drawing-in manoeuvre during forward steps. Journal of physical therapy science, 2014. 26(6): p. 889. ##
10. Ashraf, A., et al., Correlation between radiologic sign of lumbar lordosis and functional status in patients with chronic mechanical low back pain. Asian spine journal, 2014. 8(5): p. 565-570. ##
11. Sparrey, C.J., et al., Etiology of lumbar lordosis and its pathophysiology: a review of the evolution of lumbar lordosis, and the mechanics and biology of lumbar degeneration. Neurosurgical focus, 2014. 36(5): p. E1. ##
12. Teyhen, D.S., et al., The use of ultrasound imaging of the abdominal drawing-in maneuver in subjects with low back pain. Journal of Orthopaedic & Sports Physical Therapy, 2005. 35(6): p. 346-355. ##
13. Hides, J., et al., An MRI investigation into the function of the transversus abdominis muscle during “drawing-in” of the abdominal wall. Spine, 2006. 31(6): p. E175-E178. ##
14. Suehiro, T., et al., Comparison of spine motion and trunk muscle activity between abdominal hollowing and abdominal bracing maneuvers during prone hip extension. Journal of bodywork and movement therapies, 2014. 18(3): p. 482-488. ##