Virtual McKenzie Exercises and Centralization of Pain: A Pilot Study

December 3, 2025 updated by: Evidence In Motion

Low back pain (LBP) is frequently managed in physical therapy using the McKenzie method, in which a patient's directional preference-most commonly extension-is used to guide treatment. Extension-based interventions are associated with symptom improvement and centralization in many individuals with LBP. At the same time, research in pain neuroscience has shown that people with LBP may have altered cortical representations of the low back, which may contribute to pain and disability. For patients who experience high pain levels or significant fear of movement, active directional preference exercises may be difficult to perform.

Motor imagery, the mental simulation of movement without physical execution, has been shown to activate brain regions involved in movement and may help modify altered cortical representations. Preliminary research has suggested that virtual or imagery-based McKenzie extension exercises may improve pain and movement-related outcomes.

This exploratory study aims to evaluate the immediate effects of a brief motor imagery-based extension protocol in adults with LBP who demonstrate a directional preference for extension. The study will assess changes in pain intensity, disability, fear-avoidance, pain catastrophization, lumbar flexion, straight leg raise, pain distribution, and symptom centralization following a single motor imagery session.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Background and Rationale:

Low back pain (LBP) is the most common musculoskeletal condition treated in outpatient physical therapy, accounting for approximately 25-40% of patient visits. Directional preference, a key element of the McKenzie method, is widely used in the management of LBP. This approach assesses how a patient's symptoms respond to repeated or sustained directional movements-most commonly flexion or extension-and integrates the direction that reduces or centralizes symptoms into the treatment plan. Previous research demonstrates that extension-based directional preference strategies are effective for a large proportion of patients with LBP and are associated with pain reduction, increased mobility, reduced fear of movement, and centralization of radiating symptoms.

In parallel with traditional mechanical assessment and treatment methods, pain neuroscience research has highlighted the role of changes in cortical body maps, particularly in the primary somatosensory cortex (S1), in individuals with LBP. People with persistent LBP exhibit altered S1 representations, including changes in size and organization of cortical maps, which are associated with pain, disability, and functional limitations. These representations are dynamic, and movement-based therapies can help normalize them.

However, patients with high pain levels, significant fear-avoidance, or sensitized nervous systems may find movement-based interventions difficult to perform. Motor imagery-mentally simulating movement without performing it physically-may provide an alternative method for modifying cortical representations while reducing threat and avoiding symptom aggravation. Motor imagery activates neural regions similar to those used during actual movement execution and may be beneficial for individuals reluctant to engage in active movement.

Preliminary findings have suggested that virtual or imagery-based McKenzie extension movements may improve pain, fear-avoidance, catastrophization, and mobility in individuals with LBP. Because centralization of symptoms is a hallmark feature of directional preference-based care, this study aims to further explore whether a brief motor imagery-based extension protocol can influence pain intensity, body pain distribution, psychological constructs, physical measures, and centralization in patients with LBP who demonstrate an extension directional preference.

Study Objectives:

The primary objective of this study is to evaluate the immediate effects of a guided motor imagery extension protocol in patients with LBP who demonstrate a directional preference for extension. The study aims to determine whether the intervention results in changes in pain intensity, disability, fear-avoidance, pain catastrophization, lumbar flexion, straight leg raise, and pain distribution, as well as whether patients report centralization of symptoms.

Study Design:

This study is a single-group, pre-post exploratory design conducted across three outpatient physical therapy clinics. Institutional Review Board approval will be obtained prior to study initiation. Eligible patients presenting with LBP will be identified during their initial evaluation. Participants must be between 18 and 65 years of age, able to read and understand English, present with no red flags during review of systems, have no prior spinal surgery, and demonstrate a positive response to extension-based directional preference testing. Participation is voluntary and requires written informed consent.

Intervention Procedures:

Following consent, participants will complete a demographics questionnaire. A blinded therapist will administer baseline measures including disability, pain intensity, fear-avoidance beliefs, pain catastrophization, active trunk flexion, straight leg raise (SLR), and a pain body chart.

Participants will then receive a brief educational explanation of cortical map changes associated with LBP. Next, participants will assume a prone "pre-press-up" position, placing their hands under their shoulders. Instead of performing an active press-up, they will close their eyes and receive verbal guidance through a series of ten motor imagery-based lumbar extension movements. The standardized script instructs participants to visualize completing a full press-up, experiencing spinal extension, holding briefly at end range, and returning to the starting position. Total intervention time is approximately five minutes.

Immediately following the imagery protocol, a blinded therapist will repeat all outcome measures. After data collection, clinicians will resume their usual plan of care for each patient.

Outcome Measures:

Pre- and post-intervention measures include:

Oswestry Disability Index (ODI) to assess functional disability

Numeric Pain Rating Scale (NPRS) for low back and leg pain

Fear Avoidance Beliefs Questionnaire (FABQ), including Physical Activity and Work subscales

Pain Catastrophization Scale (PCS)

Active lumbar flexion (fingertip-to-floor distance in centimeters)

Straight Leg Raise measured with an inclinometer

Body chart with grid overlay to quantify pain distribution and potential changes in cortical representation

Data Management and Analysis:

De-identified data will be compiled and analyzed using descriptive statistics for demographic variables. Pre- and post-intervention comparisons will be performed using paired-samples t-tests with significance set at p < 0.05. Significant findings will be confirmed with Wilcoxon Signed Ranks nonparametric testing.

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

Age 18 to 65 years

Presenting to outpatient physical therapy with low back pain (LBP)

Able to read and understand English

No red flags identified during review of systems and initial physical therapy evaluation

No prior spinal surgery

Demonstrates a positive response to extension-based directional preference testing

Willing and able to provide written informed consent

Exclusion Criteria:

Age younger than 18 or older than 65

Inability to read or understand English

Presence of red flags during review of systems (e.g., suspected fracture, malignancy, infection, cauda equina symptoms)

History of spinal surgery

No demonstrable directional preference for extension during evaluation

Any condition that the evaluating clinician determines would preclude safe participation

Declines to participate or is unable to provide informed consent

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Motor Imagery Extension Protocol
Participants with low back pain who demonstrate a directional preference for extension will receive a single session of a guided motor imagery protocol simulating lumbar extension movements based on the McKenzie method. The intervention is designed to mentally replicate an extension press-up without requiring physical movement.
Behavioral: Motor Imagery-Based Lumbar Extension

Participants will lie prone with hands positioned under the shoulders in a standard "pre-press-up" position. With eyes closed, participants will be verbally guided through ten imagined lumbar extension press-ups. The standardized motor imagery script includes:

Focusing attention on current back and leg symptoms

Imagining pushing the arms into extension

Visualizing the back arching into extension

Holding the imagined end-range position for several seconds

Imagining returning to the starting position in a controlled manner

Repeating this process ten times

Total duration of the protocol is approximately 5 minutes.

Mode of Delivery:

In-person, guided by a physical therapist trained in the study protocol.

Purpose:

To evaluate immediate changes in pain, disability, psychological measures, physical mobility, neurodynamic measures, and symptom centralization following a motor imagery-based extension intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Low Back Pain Intensity (NPRS - Low Back)
Time Frame: Pre-intervention to immediately post-intervention (same session).
Change in self-reported low back pain intensity measured using the 0-10 Numeric Pain Rating Scale (NPRS), where 0 = no pain and 10 = worst imaginable pain.
Pre-intervention to immediately post-intervention (same session).
Leg Pain Intensity (NPRS - Leg)
Time Frame: Pre-intervention to immediately post-intervention (same session).
Change in self-reported leg pain intensity using the 0-10 NPRS.
Pre-intervention to immediately post-intervention (same session).

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Oswestry Disability Index (ODI)
Time Frame: Pre-intervention to immediately post-intervention.
Change in disability level measured by the 10-item ODI questionnaire. Scores range from 0-50, multiplied by 2 to produce a percentage (0-100%), with higher scores indicating greater disability.
Pre-intervention to immediately post-intervention.
Fear-Avoidance Beliefs Questionnaire (FABQ) - Physical Activity Subscale
Time Frame: Pre-intervention to immediately post-intervention.
Change in fear-avoidance beliefs related to work. The 7-item FABQ-W yields scores from 0-42, with higher scores indicating greater work-related fear-avoidance.
Pre-intervention to immediately post-intervention.
Pain Catastrophization Scale (PCS)
Time Frame: Pre-intervention to immediately post-intervention.
Change in pain catastrophizing as measured by the 13-item PCS. Total scores range from 0-52, with higher scores indicating greater catastrophic thinking about pain.
Pre-intervention to immediately post-intervention.
Active Lumbar Flexion (Fingertip-to-Floor Distance)
Time Frame: Pre-intervention to immediately post-intervention.
Change in active trunk forward flexion measured in centimeters from the tip of the longest finger of the dominant hand to the floor. Lower values indicate greater lumbar and hamstring mobility.
Pre-intervention to immediately post-intervention.
Straight Leg Raise (SLR)
Time Frame: Pre-intervention to immediately post-intervention.
Change in SLR measured using an inclinometer placed on the tibia. SLR is measured on the most affected leg, with the ankle maintained in neutral. Degrees of hip flexion are recorded.
Pre-intervention to immediately post-intervention.
Pain Distribution (Body Chart Grid Count)
Time Frame: Pre-intervention to immediately post-intervention.
Change in pain distribution measured using a standardized body chart. Pain areas are quantified using a grid overlay, producing a count of regions marked by the participant.
Pre-intervention to immediately post-intervention.
Symptom Centralization (Qualitative Report)
Time Frame: Immediately post-intervention.
Presence or absence of centralization of symptoms based on patient self-report during or after the motor imagery extension protocol. Centralization is defined as a proximal shift of pain toward the lumbar spine.
Immediately post-intervention.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Evidence In Motion

Collaborators

University of Nevada, Las Vegas
College of St. Scholastica, Inc.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

December 1, 2025

Primary Completion (Estimated)

May 1, 2026

Study Completion (Estimated)

November 1, 2026

Study Registration Dates

First Submitted

December 3, 2025

First Submitted That Met QC Criteria

December 3, 2025

First Posted (Actual)

December 16, 2025

Study Record Updates

Last Update Posted (Actual)

December 16, 2025

Last Update Submitted That Met QC Criteria

December 3, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • VirtualMcKenzie2025

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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