Supplemental PowerPoint Slides McKenzie Lumbar Classification: Inter-Rater Agreement by Physical Therapists with Different Levels of Formal McKenzie Post-graduate Training Mark W. Werneke, PT, MS, Dip. MDT, Daniel Deutscher, PT, PhD, Dennis L. Hart, PT, PhD (deceased), Paul Stratford, PT, MSc, Joel Ladin PT, Jon Weinberg, PT, Dip. MDT Scott Herbowy, PT, Dip. MDT Linda Resnik, PT, PhD Copyright © 2013 Lippincott Williams & Wilkins. Unauthorized commercial reproduction of this slide is prohibited Israel McKenzie Reliability Study Purpose was to: determine if the level of formal McKenzie postgraduate training (Parts A& B, C, and D) was associated with inter-rater chance-corrected agreement for classifying patients with LBP into the following McKenzie classification levels: Main McKenzie syndromes Presence of Reducible lateral shift and irreducible derangement Directional preference Centralization Israel McKenzie Reliability Study Results and Key Points: Results indicate below acceptable agreement for judging all levels of the McKenzie classification system between physical therapist raters completing McKenzie post graduate training Parts A-D. The unacceptable agreement levels raise questions about the clinical utility of the McKenzie classification system at these training levels. Future research is warranted to examine the implementation and educational processes required to obtain adequate agreement in the McKenzie classification system.