Effect of Peripheral Magnetic Stimulation in Patients With Chronic Lower Back Pain - Controlled, Randomized Clinical Trial
Phase: NA
Conditions: Low Back Pain
Sponsor: Inês Gomes

Cover Page 
Official Study Title 
Effect of Peripheral Magnetic Stimulation in Patients With Chronic Lower Back Pain 
 
ClinicalTrials.gov Identifier (NCT Number) 
NCT07243548 
 
Unique Protocol ID 
CEEM1329 
 
Document Type 
Study Protocol / Clinical Study Documentation 
 
Document Date 
03 March 2024 
 
Confidentiality Statement 
This document contains proprietary and confidential information intended solely for 
regulatory review, ethics committee submission, or authorized study personnel. 
Unauthorized distribution or reproduction is prohibited. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

METHODOLOGY 
Study design 
A clinical, controlled, randomized, multicenter study will be conducted. 
Study Location and Population 
The study will be developed at the Physiotherapy School Clinic of the Federal 
University of Alfenas (MG/Brazil), at the Laboratory of Neuroscience, Neuromodulation and 
Pain Study - LANNED, located in the municipality of Alfenas, Minas Gerais and at the Egas 
Moniz School of Health and Science (Portugal), at the Neuromodulation and Pain Unit - 
NeuroPain, in the Municipality of Almada, Setúbal. 
Sample 
Individuals with chronic low back pain with a score between 40 and 80 on the 
Oswestry scale will be selected, and 40 will be selected for treatment at the Physiotherapy 
School Clinic of the Federal University of Alfenas - MG and Egas Moniz University Clinic - 
CUEM. Subjects will be divided into 2 groups: the control group and the intervention group. 
Inclusion criteria  
The inclusion criteria considered: individuals complaining of low back pain for more 
than three months, non-practicing sports activities, absence of significant pathologies of 
the spine such as previous history of myelopathy, surgeries, instabilities or deformities in 
the spine (bone fractures), normal neurological examination for radiculopathies (patellar 
and Achilles tendon reflexes; voluntary motor function; sensitivity test). 
Exclusion criteria 
Exclusion criteria are: trauma or systemic dysfunction; use of other alternative 
treatments; refusal to be randomized; protrusion or prolapse of one or more intervertebral 
discs with neurological symptoms; previous spine surgery; infectious spondylopathy; low 
back pain secondary to inflammation, tumor, or autoimmune disease; congenital 
deformities in the spine; compressive fracture caused by osteoporosis, spondylolysis, or 
spondylolisthesis (Zaringhalan et al.,  2010). Individuals who use prostheses; who have a 
history of seizures; have a history of epilepsy, and have metal or intracranial devices 
implanted or non-removable. 
Randomization of samples: 
Volunteers will be divided into a control group and an intervention group through 
randomization. To this end, the participants will be allocated by another researcher, who 
will use the Research Randomizer website in two groups: Control group (CG) and 
Intervention group (IG). 

Sample calculation 
The sample size calculation carried out according to Hulley and Cumminhs (1998) 
estimates the number of 15 volunteers per group. This calculation will be performed to 
ensure a statistical power of 85% (β=0.20) and significance level when p 0.05.  
Evaluation Instruments: 
Visual Analog Scale (VAS) 
The VAS is a scale similar to a ruler, numbered with a starting point of zero and 
ending at ten, with 0 being no pain and 10 being the most unbearable pain felt at that 
moment by the patient (Collins, 1997). 
The VAS was used to quantify the intensity and perception of the individual about 
their pain, and was graded according to ordinal scores: no pain (0), mild pain (1 to 2), 
moderate (3 to 5) and severe pain (6 to 10) (Toniolli & Pagliuca, 2003). 
Pressure Pain Threshold (PPT) 
The LDPs will be evaluated using a portable pressure algometer, with a 1 cm2 rubber 
tip applicator, with a communication interface via Bluetooth, placed perpendicularly on the 
skin with an application rate of 0 to 15 Kgf/s (Physiocode brand). PPT will be defined as the 
minimum pressure first evoking a sensation of pain. The PPTs will be measured twice with a 
10-second interval for each point, and the average value will be used for statistical analysis. 
(Balaguier, Madeleine, & Vuillerme, 2016) 
Algometry was used to examine the pain threshold for the pressure applied between 
the spinous processes of the lumbar spine L1-L5. (Binderup, Arendt-Nielsen, & Madeleine, 
2010) 
Oswestry Range (ODI) 
The Oswestry Disabilty Index ( ODI) is a disease-specific instrument recommended 
for the evaluation of spinal disorders. The ODI is an ordinal instrument, where 10 criteria are 
analyzed with six response alternatives for each criterion. The total count ranges from 0 to 
100, with zero corresponding to normal function and 100 indicating great disability. For each 
item, zero is normality and five is the greatest functional change. The sum of the 10 
questions divided by five multiplied by the number of questions answered, and multiplying 
everything by 100, constitutes the ODI (Fairbank JCT, 2000). 
Repeated Peripheral Magnetic Stimulation (rRPMS) 
Both groups will use the rRPMS device, with 10 sessions over a period of 2 weeks, in 
the IG applied in flat tangential orientation lasting 20 minutes and intermittent stimulation 

protocol consisting of 5 seconds of stimulation at a frequency of 20 Hz followed by 25 
seconds of rest with a minimum intensity of 20% up to maximum intensity to induce 
sufficient contraction of the paraspinal muscle and in the CG in transverse orientation with 
The stimulus intensity level set at 5% of the maximum stimulator output to minimize 
stimulation, both in the most painful lumbar region. 
The group will be randomized into IG (n=25) and CG (n=25). A round coil is known to 
be more advantageous than a figure-8 coil for stimulating structures in a deep layer like the 
spinal roots and covering a larger area like a paravertebral muscle group (Beaulieu LD, 
2015). Thus, we will use the round coil that will be most suitable for the treatment of low 
back pain.  
The stimulation site will be determined based on the patient's most sensitive point 
before the start of each treatment session. For patients in the rPMS intervention group - in 
the prone position - the coil will be placed in a flat tangential orientation targeting the most 
painful lumbar region. In this way, it will allow the coil to be positioned parallel to the 
surface of the body, thus maximizing the effects of the magnetic stimulation applied to the 
area.  
For patients in the rPMS control group, also in the prone position, the coil will be 
applied in a transverse orientation in the most painful lumbar region. This position of the 
coil, at an angle of 90° to the surface of the body, will minimize the effects of magnetic 
stimulation applied to the area. 
Both groups will undergo 10 sessions over a period of 2 weeks. Each session 
lasted 20 minutes and intermittent stimulation protocol consisted of 5 seconds of 
stimulation at the 20 Hz frequency followed by 25 seconds of rest. The total number of 
stimuli over 20 minutes will be 4,000 pulses.   
The level of stimulation intensity will be determined at the level that induces 
sufficient contraction of the paraspinal muscle while still within the patient's tolerable 
range. For the rRPMS control group, the stimulus intensity level will be set at 5% of the 
stimulator's maximum output to minimize magnetic stimulation.   
Both groups will be exposed to an identical clicking sound generated during each 
session and the coil will be placed in contact with the patient (to have a similar sensation). 
The application of the rRPMS coil in both groups of patients will be conducted by 
experienced physiotherapists with sufficient preliminary training on the application of rPMS 
prior to the study.  

Ethical Issues 
This project was submitted to the evaluation of the Ethics Committee of the Federal 
University of Alfenas, and will comply with the precepts contained in resolution 466/12 of 
the National Health Council. It will be submitted to the Egas Moniz Ethics Commission. 
Before starting to participate in this research, volunteers will receive all information related 
to the objectives and methodological procedures of the study and after agreeing to 
participate, they will sign the free and informed consent form. Participants will be informed 
about the objectives, research procedures, risks, benefits and minimizing measures, the 
data being presented together, the informant may withdraw his participation at any time.  
Statistical Procedures 
Data were analyzed using both within-group and between-group comparisons to 
evaluate the effects of repetitive peripheral magnetic stimulation (PMS) in individuals with 
chronic low back pain. Continuous variables were summarized as means and standard 
deviations, and the assumption of normality was assessed using the Shapiro–Wilk test. 
Paired Student’s t-tests were applied to assess within-group (pre- vs. post-intervention) 
differences, while between-group comparisons of change scores (Δ values) were 
conducted using Welch’s t-tests to account for possible variance inequality. 
For binary categorical outcomes, such as the presence of positive clinical signs, 
McNemar’s test was used for within-group comparisons, and Pearson’s Chi-square test 
was applied for between-group analyses using 2×2 contingency tables. The significance 
threshold was set at p < 0.05 for all tests. 
Effect sizes were calculated using Cohen’s d, derived from the difference in pre-post 
deltas between groups. Values were interpreted according to standard conventions, with 
effect sizes around 0.8 or higher considered large. Negative d values indicated greater 
improvement in the PMS group for outcomes where lower scores reflect improvement (e.g., 
Oswestry Disability Index, pain VAS), whereas positive d values indicated greater 
improvement in outcomes where higher scores reflect improvement (e.g., pressure pain 
thresholds, Schober test). 
All statistical analyses were conducted using GraphPad Prism (version 8.0) and IBM 
SPSS Statistics (version 25). 
 

Informed Consent 
Code| IMP-EM-PE-17_03 
 
 
 
 
 
____________,___________________________________. 
 
 
 
 
(Place)              (DD Month YYYY) 
 
You are being invited to participate, as a volunteer, in the research project EFFECT OF 
PERIPHERAL MAGNETIC STIMULATION IN PATIENTS WITH CHRONIC LOW BACK PAIN – 
Randomized controlled clinical trial, under the responsibility of the investigator Prof. Dr. 
Luciano Maia Alves Ferreira. 
 
Read the following carefully and ask me about any questions you have. After being informed 
about the research, and if you accept to be part of our study, sign at the end of this 
document, which is contained in two copies. One way belongs to you and the other to the 
researcher in charge. Your participation is not mandatory, and at any time you may withdraw 
from participating and withdraw your consent. Your refusal will not cause any harm to your 
relationship with the researcher or the institution. In case of refusal you will not suffer any 
penalty. 
 
When reading the items below, you must declare whether you have been sufficiently 
informed about the stages of the research at the end of this document. 
This research aims to investigate the effects of treatment with peripheral magnetic 
stimulation (rPMS) compared to a placebo treatment with the same equipment in reducing 
pain and functionality of patients with chronic low back pain. 
Your participation in this research will consist of a study that will be developed at the 
Laboratory of Functional Physical Assessment in Physical Therapy – LAFFFi of Egas Moniz. 
Individuals with chronic low back pain with a score between 40 and 80 on the Oswestry scale 
will be selected. Some questionnaires will be applied to assess the patient's quality of life, 
pain level, measure the functional disability of patients with low back pain and assess pain. 
It will be done in 10 sessions over a period of 2 weeks, with each session lasting 30 minutes. 
It will be performed by an experienced professional. 
During the execution of the survey, there may be minimal risks such as embarrassment, 
availability of time to answer the instrument, discomfort when answering the questionnaire 
and improper disclosure of confidential data. As a minimizing measure, if there are 
embarrassments and/or discomfort of the participants when answering the questions when 
poorly formulated, which will also be solved through the previous training of the researchers 

Informed Consent 
Code| IMP-EM-PE-17_03 
 
 
 
 
before making the form and the non-obligation to answer them. The participant may 
interrupt the process whenever they wish; ensure confidentiality and privacy. Their 
participation consists of agreeing to collaborate with the research and answer the 
questionnaire. 
The main risks are related to the physical components of the participants, due to the 
possibility of discomfort during or after the application of the proposed protocol. During the 
application of neuromodulation, it is possible that the participant will experience sensations 
of pain, itching or tingling in the scalp region. It is important to highlight that these 
sensations have a low frequency, low magnitude, and are related to the stimulation period. 
The stimulation machine emits a noise with each pulse, which can be a nuisance. 
By participating in this work you will contribute to improvements in the research area and 
it is expected that after the intervention of this research you will bring benefits in the 
improvement of chronic low back pain. 
Your participation in this project will last 10 sessions over a period of 2 weeks, with each 
session lasting 30 minutes. You will not have any expenses for your participation, and the 
questionnaires, interviews, classes, courses, lectures, consultations/exams/treatments/etc. 
are completely free; and will cease to participate or withdraw their consent at any time, 
without having to justify it, and will not suffer any loss. 
You have been informed that the data collected will be used, solely and exclusively, for the 
purposes 
of 
this 
research, 
and 
that 
the 
results 
of 
the 
research 
may 
be 
published/disseminated through academic works or scientific articles by professionals in the 
area. 
For these reasons: 
I AUTHORIZE ( ) / DO NOT AUTHORIZE ( ) the collection and dissemination of 
images/photographs/videos/voice sound for the present research. 
I,  
,  NIF 
, 
declare that I have been informed and agree to participate, as a volunteer, in the research 
project described above. 
 
................................................. 
................................................. 
(Signature of the participant) 
       (Signature of the principal investigator)