Download the full-sized PDF of Therapeutic Contextual Factors in Physiotherapy: Magnitude, Mechanisms and Contributors  of Placebo Mediated Analgesia in Chronic Low Back PainDownload the full-sized PDF



Permanent link (DOI):


Export to: EndNote  |  Zotero  |  Mendeley


This file is in the following communities:

Graduate Studies and Research, Faculty of


This file is in the following collections:

Theses and Dissertations

Therapeutic Contextual Factors in Physiotherapy: Magnitude, Mechanisms and Contributors of Placebo Mediated Analgesia in Chronic Low Back Pain Open Access


Other title
low back pain
Type of item
Degree grantor
University of Alberta
Author or creator
Fuentes Contreras, Jorge Patricio
Supervisor and department
Dr. Douglas Gross, Department of Physical Therapy
Dr. David Magee, Department of Physical Therapy
Examining committee member and department
Saifee Rashiq, BMedSci, BM BS, MSc (Epid) DA (UK), FRCPC, Professor Department of Anaesthesiology and Pain Medicine, University of Alberta.
Sharon Warren, PhD. Professor Faculty of Rehabilitation Medicine, University of Alberta
Bruce Dick, Ph.D. Associate Professor Depts. of Anesthesiology and Pain Medicine, Psychiatry & Pediatrics, University of Alberta
Anthony Joyce, Ph.D. Professor, Department of Psychiatry University of Alberta
Steven George, Ph.D. Associate Professor, Assistant Department Chair, and DPT Program Administrator University of Florida Department of Physical Therapy.
Faculty of Rehabilitation Medicine
Rehabilitation Science
Date accepted
Graduation date
Doctor of Philosophy
Degree level
Mechanisms through which physiotherapy influence musculoskeletal pain include both the specific ingredient of an intervention as well as contextual factors inherent to clinical encounters including the therapist, patient and setting. These contextual factors are often termed “non-specific” effects and are associated with the placebo effect. Although well documented in other areas, the impact of contextual factors in treatment of low back pain (LBP) is unknown. In addition, the contributors to the physiotherapy placebo response in LBP have not been elucidated. This project investigated the effect of contextual factors in patients with LBP receiving either active or sham interferential current therapy (IFC). Determinants of a favorable response to the placebo response were also explored. A sample of 117 chronic LBP participants were randomly assigned into 4 groups: active limited (AL) included the application of active IFC in a limited therapeutic encounter (i.e. limited patient-practitioner interaction), sham limited (SL) included sham IFC in a limited therapeutic encounter, active enhanced (AE) included active IFC in an enhanced therapeutic encounter (i.e. supportive patient-practitioner relationship, encouragement), and sham enhanced (SE) included sham IFC in an enhanced therapeutic encounter. Outcomes included pain intensity (PI-NRS) and muscle pain sensitivity (PPT). Analysis included MANOVA, and logistic regression. Also, clinical significance was determined. There were statistically significant differences between groups on PPT’s and PI-NRS (baseline and after treatment). Mean differences in PI-NRS were 18.3 mm, 10.0 mm, 31.4 mm, and 22.2 mm, for the groups AL, SL, AE, and SE respectively. Clinically important effect sizes were found. Mean differences in PPT’s were 1.2 kg, 0.3 kg, 2.0 kg, and 1.7 kg for the group AL, SL, AE, and SE respectively. Again, clinically important effect sizes were found. The level of therapeutic alliance and pain duration were the factors associated with the placebo response. Results highlight the important role of contextual factors in the treatment of patients with chronic LBP. Enhanced therapeutic relationship was associated with meaningful clinical improvement. Also, perceived therapeutic alliance was associated with placebo response. Factors other than the specific ingredient of a treatment may have a large role in achieving positive clinical outcomes, and exploring them is central to physiotherapy practice.
Permission is hereby granted to the University of Alberta Libraries to reproduce single copies of this thesis and to lend or sell such copies for private, scholarly or scientific research purposes only. Where the thesis is converted to, or otherwise made available in digital form, the University of Alberta will advise potential users of the thesis of these terms. The author reserves all other publication and other rights in association with the copyright in the thesis and, except as herein before provided, neither the thesis nor any substantial portion thereof may be printed or otherwise reproduced in any material form whatsoever without the author's prior written permission.
Citation for previous publication
Fuentes JP, Armijo-Olivo S, Magee DJ, Gross DP. Effectiveness of Interferential Current Therapy in the Management of Musculoskeletal Pain: Systematic Review and Meta-Analysis Physical therapy 2010; 90 (9):1219-1238. Fuentes JP, Armijo-Olivo S, Magee DJ, Gross DP. A preliminary Investigation into the Effects of Interferential Current Therapy and Placebo on Pressure Pain Sensitivity: a Random Crossover Placebo Controlled Study. Physiotherapy 2011; 97(9):291-301.

File Details

Date Uploaded
Date Modified
Audit Status
Audits have not yet been run on this file.
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 8839063
Last modified: 2015:10:12 14:33:51-06:00
Filename: Fuentes_Jorge_Spring 2013.pdf
Original checksum: 10d3034478f65273d6db4c0b61eacb77
Well formed: true
Valid: true
Status message: Too many fonts to report; some fonts omitted. Total fonts = 1107
File title: Microsoft Word - Thesis Complete
File author: user
Page count: 319
Activity of users you follow
User Activity Date