Investigating the Hypoalgesic Effects of Manipulative Therapy Using Pain Conditioning and Expectations in Low Back Pain

Summary

The objective of this study will be to identify whether a conditioning procedure by the surreptitious downgrade of a noxious stimulus intensity associated with induced positive expectations about treatment will result in greater hypoalgesic effects when compared to positive verbal suggestions (positive expectation induction) alone regarding the effects of spinal manipulative therapy intervention in patients with CLBP. This study will enroll 264 individuals with CLBP aged between 18 and 60 years. Spinal Manipulative Therapy in the lumbar spine will be administered to all participants during 5 sessions.

First assessment session - participants will be submitted to a quantitative sensory testing (QST) to determine the heat pain threshold (calibration test) to run the conditioning procedure. Afterward, participants will be allocated by a blinded researcher into the following subgroups: hidden conditioning + positive expectation (G1); positive expectation alone (G2) and a group submitted to neutral expectations (G3) about the treatment.

First treatment session - Firstly, participants will receive instructions with the aim to induce positive (or neutral) expectations by means of a workshop. Secondly, all the participants will be submitted again to the pre-conditioning test, using the more intense pain stimulus obtained in the calibration test, then patients will be assessed regarding pain intensity and finally submitted to the manipulative therapy. At the end of the first treatment session, the conditioning test will be repeated, but the heat pain threshold of the hidden conditioning group (G1) will be surreptitiously downgraded (from intense pain stimulus to moderate pain stimulus) as a means of conditioning patients to believe that manipulative therapy promoted pain relief. Pain intensity will be assessed again to confirm a decrease in pain intensity.

Outcomes will be assessed three times: immediately after the five therapy sessions, one month later, and three months later. The primary outcomes assessed will be pain intensity and global perceived effect of improvement. The secondary outcome will be low back pain disability.

Conditions

• Chronic Low Back Pain

Interventions

PROCEDURE

Procedure/Surgery: Experimental: Hidden conditioning + Positive Expectation

Patients will be submitted to quantitative sensory testing to determine different thresholds of noxious heat pain stimulus (intense, moderate or weak). Afterward, participants will receive instructions with the aim to induce positive expectations about the treatment by means of a workshop. Immediately after the first session of manipulative therapy, participants will be submitted again to the QST but now the heat pain threshold of the hidden conditioning group will be surreptitiously downgraded (the intense noxious stimulus will be downgraded to the moderate stimulus - individually obtained during the QST) as a mean to conditioning patients to believe that spinal manipulative therapy promoted pain relief. Patients will be invited to report the pain intensity perceived just after the QST (second test - conditioning procedure). The objective of questioning the pain intensity after the conditioning test is a procedure check to ensure that the conditioning procedure worked.

PROCEDURE

Procedure/Surgery: Active Comparator: Positive Expectation

Patients in this group will be submitted to a quantitative sensory testing to determine different thresholds of noxious heat pain stimulus (intense, moderate or weak). Afterward, participants will receive instructions with the aim to induce positive expectation about the treatment by means of a workshop. Immediately after the first session of spinal manipulative therapy, participants will be submitted again to the QST (without downgrading of the intense noxious heat stimulus). Patients will be invited to report the pain intensity perceived during the QST after the intervention. The objective of questioning the pain intensity in this group is a procedure check - to investigate whether the positive instructions will show any effect.

PROCEDURE

Procedure/Surgery: Active Comparator: Neutral Expectation

Patients in this group will be submitted to a quantitative sensory testing to determine different thresholds of noxious heat pain stimulus (intense, moderate or weak). Afterward, participants will receive instructions with the aim to induce neutral expectation about the treatment by means of a workshop. Immediately after the first session of spinal manipulative therapy, participants will be submitted again to the QST (without downgrading of the intense noxious heat stimulus). Patients will be invited to report the pain intensity perceived during the QST after the intervention. The objective of questioning the pain intensity in this group is a procedure check - to investigate/confirm the effect of neutral instructions.

PROCEDURE

Spinal Manipulative Therapy

All the groups recruited in the study will receive five sessions of Spinal Manipulative Therapy. The intervention will be performed with the patient in the supine position. The clinician-researcher will passively lean over the patient to the side to be manipulated and ask the patient to place their hands behind their head. The researcher will then passively rotate the patient on the side to be manipulated and perform a posterior and inferior thrust on the opposite anterosuperior spine. The patients will receive 4 maneuvers (twice towards right side and twice towards left side).

Sponsors & Collaborators

• Fundação de Amparo à Pesquisa do Estado de São Paulo

  collaborator OTHER_GOV

• Universidade Federal de Sao Carlos

  lead OTHER

Principal Investigators

• Thais Chaves, PhD · Federal University of São Carlos - UFSCar

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-02-20

Primary Completion

2023-12-10

Completion

2024-03-10

Countries

• Brazil

Study Locations