Lumbar Flexion-Relaxation Phenomenon

This two-page textbook spread was created for a biomechanics assignment in the Biomedical Communications program. Dr. Tyson Beach, a faculty member of the Department of Kinesiology at the University of Toronto, served as the content adviser for this project, providing feedback on accuracy of both text and images. The series of illustrations aims to communicate the hypothesized biomechanical underpinnings of the lumbar-flexion relaxation phenomenon (FRP) and key clinical implications thereof. 

Clients: Prof. Michael Corrin; Dr. Tyson Beach, PhD

Audience: undergraduate kinesiology students

Format: print (textbook)

Medium: Adobe Illustrator

Date: January 2018

Final artwork

Process work

Coming soon!


1. Agur, A. M. R., & Dalley, A. F. (2009). Grant’s Atlas of Anatomy (12th ed.). Lippincott Williams & Wilkins.

2. Andersson, E. A., Oddsson, L. I. E., Grundström, H., Nilsson, J., & Thorstensson, A. (1996). EMG activities of the quadratus lumborum and erector spinae muscles during flexion-relaxation and other motor tasks. Clinical Biomechanics, 11(7), 392–400.

3. Colloca, C. J., & Hinrichs, R. N. (2005). The Biomechanical and Clinical Significance of the Lumbar Erector Spinae Flexion-Relaxation Phenomenon: A Review of Literature. Journal of Manipulative and Physiological Therapeutics, 28(8), 623–631.

4. McGill, S. M. (2007). Low Back Disorders: Evidence-Based Prevention and Rehabilitation (2nd ed.). Winsor, ON: Human Kinetics.

5. McGill, S. M., & Kippers, V. (1994). Transfer of loads between lumbar tissues during the flexion-relaxation phenomenon. Spine, 19(19), 2190–6.

6. Potvin, J. R., McGill, S. M., & Norman, R. W. (1991). Trunk muscle and lumbar ligament contributions to dynamic lifts with varying degrees of trunk flexion. Spine.

7. Schuenke, M., Schulte, E., & Schumacher, U. (2010). Atlas of Anatomy: General Anatomy and Musculoskeletal System. (L. M. Ross & E. D. Lamperti, Eds.). New York: Thieme.

8. Solomonow, M., Baratta, R. V, Banks, A., Freudenberger, C., & Zhou, B. H. (2003). Flexion-relaxation response to static lumbar flexion in males and females. Clinical Biomechanics (Bristol, Avon), 18(4), 273–9.