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Trial registered on ANZCTR


Registration number
ACTRN12623000065695
Ethics application status
Approved
Date submitted
10/01/2023
Date registered
18/01/2023
Date last updated
18/01/2023
Date data sharing statement initially provided
18/01/2023
Type of registration
Retrospectively registered

Titles & IDs
Public title
Changes in pain sensitivity in chronic low back pain: A crossover randomised controlled trial
Scientific title
The effect of an acute bout of isometric exercise on pain sensitivity in adults aged 18 to 55 with chronic low back pain: a randomised crossover trial
Secondary ID [1] 308712 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Chronic low back pain 328644 0
Condition category
Condition code
Musculoskeletal 325656 325656 0 0
Other muscular and skeletal disorders
Physical Medicine / Rehabilitation 325657 325657 0 0
Other physical medicine / rehabilitation

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Participants will randomly receive each of the three interventions once per week over a period of three weeks with the intervention sequence for each intervention randomized electronically. The interventions will be delivered to each participant individually, face-to-face by a research assistant, who is a Master of Clinical Exercise Physiology student with experience in delivering exercise interventions to individuals with chronic pain. The interventions will be delivered indoors at the Deakin University Clinical Research Facility. There will be a washout period of 7 days between interventions.
The three interventions consist of:

A) Isometric wall squat (true intervention)
Participants will perform a single repetition of an isometric wall squat, held at 100 degrees knee flexion for four minutes or until volitional fatigue. Knee flexion will be measured by placing a goniometer on the lateral epicondyle of the knee, in line with the femur whilst the anchor arm will be in line with the lateral malleolus. Participants will be instructed to place hands across chest, their back flat against the wall and position their feet parallel to each other and spaced shoulder width apart for the exercise position. The team member delivering the intervention will monitor the time under contraction with a stopwatch. Instructions will be standardized for each participant and a neutral language script will be used to control for expectation bias.

B) Multiple repetition wall squat (placebo)
The placebo exercise will consist of multiple repetitions of an isometric wall squat held for 5 seconds at a knee joint angle of 100 and then 120 degrees, repeated 3 times each with a 30 second rest in standing between repetitions. Knee flexion will be measured by placing a goniometer on the lateral epicondyle of the knee, in line with the femur whilst the anchor arm will be in line with the lateral malleolus. Participants will be instructed to place hands across chest, their back flat against the wall and position their feet parallel to each other and spaced shoulder width apart for the exercise position. Participants will firstly perform the exercise at 100 degrees of knee flexion for 3 X 5 second repetitions with 30 seconds of rest in between. Then participants will perform a further 3 X 5 second repetition with 30 seconds of rest in between at 120 degrees of knee flexion. This intensity and volume of exercise is well below the threshold expected to produce exercise induced hypoalgesia based on existing literature in pain-free and chronic pain populations. The team member delivering the intervention will monitor exercise time with a stopwatch. Instructions will be standardised for each participant and a neutral language script will be used to control for expectation bias and maintain blinding of participants to the true intervention.

C) Quiet rest (control)
Participants will remain seated in a chair for 4 minutes. Participants will be instructed to rest quietly in a chair. Participants will be instructed to refrain from using any technological devices including mobile phones and computers for the duration of quiet rest. The team member delivering the intervention will monitor the time with a stopwatch. Instructions will be standardized for each participant and a neutral language script will be used to reduce expectation bias.
Intervention code [1] 325173 0
Treatment: Other
Comparator / control treatment
The control treatment will be the quiet rest arm.
Control group
Active

Outcomes
Primary outcome [1] 333501 0
Pain sensitivity: Pressure pain threshold will measure pain sensitivity bilaterally at the forearm, calf and paraspinals with a handheld pressure algometer (J Tech Medical Industries, Salt Lake City, USA).
Timepoint [1] 333501 0
Immediately prior to each intervention, and immediately (primary timepoint) following and 10, 20- and 30-minutes post intervention.
Primary outcome [2] 333502 0
Changes to pain sensitivity: Pressure pain thresholds will be reassessed immediately following the intervention (same protocol as pre-exercise) to determine changes in pain sensitivity. Mean pressure pain thresholds taken at each post time point (immediately after exercise, 10 minutes, 20 minutes, 30 minutes) will be subtracted from mean pressure pain thresholds pre-intervention to determine change in pain sensitivity over time. A positive value will indicate that pain sensitivity decreased (pressure required to reach pain increased). A negative value will indicate the pain sensitivity increased and that exercise induced hyperalgesia occurred. This will be completed separately for each testing region (forearm, back and calf) and pooled (global).
Timepoint [2] 333502 0
Immediately prior to intervention and immediately following (primary timepoint) and 10, 20- and 30-minutes post intervention.
Secondary outcome [1] 417297 0
Low back pain intensity: A 0-100mm visual analogue scale (VAS) will measure pain intensity (low back pain intensity)
Timepoint [1] 417297 0
Immediately prior to intervention and immediately following and 10, 20- and 30-minutes post intervention.
Secondary outcome [2] 417298 0
Expectations for the effect of exercise on pain intensity: To assess whether expectations moderate change in low back pain intensity, a single item questionnaire (doi:10.1249/MSS.0000000000002396.) will be completed by the participants at the end of each visit. The questionnaires will ask participants whether they expected an increase or decrease in pain intensity following the intervention. Each question will be scored on a scale of -10 to +10, with +10 indicating an expectation of a lot more low back pain intensity whilst -10 would indicate that they expected a lot less low back pain intensity. A score of 0 on both scales would indicate that they expected no change as a result of the intervention.
Timepoint [2] 417298 0
30-minutes post intervention.
Secondary outcome [3] 417299 0
Expectations for the effect of exercise on changes to pain sensitivity: To assess whether expectations moderate change in pain sensitivity, a single item questionnaire (doi:10.1249/MSS.0000000000002396.) will be completed by the participants at the end of each visit. The questionnaire will ask participants whether they expected an increase or decrease in pressure pain threshold following the intervention. Each question will be scored on a scale of -10 to +10, with +10 indicating an expectation of a lot greater pressure pain threshold -10 would indicate that they expected a lot less pressure pain threshold. A score of 0 on both scales would indicate that they expected no change as a result of the intervention.
Timepoint [3] 417299 0
30-minutes post intervention.
Secondary outcome [4] 417303 0
Physical activity levels (International Physical Activity Questionnaire)
Timepoint [4] 417303 0
Prior to each testing session.
Secondary outcome [5] 417304 0
Medication use and smoking status: Participants will complete a 4-item questionnaire to record their medication use over the previous week. The questionnaire will firstly ask “are you currently taking any medication as treatment for you low back pain”, answered with yes or no. If answered yes, participants will be prompted with a second question asking to list the medication they are taking. The third questionnaire will ask the participant to indicate the frequency they take each medication by asking “for this medication, what is the frequency you take this in the prior week”. The fourth question will ask participants to state when they last took an analgesic medicine. A separate questionnaire will be used to determine smoking status of the participants. This questionnaire will ask participants whether they are a current smoker, prior smoker, and list on average, how many cigarettes they smoke per day.
Timepoint [5] 417304 0
Prior to each testing session.
Secondary outcome [6] 417623 0
Confirmation of adequate blinding of intervention: After participants are exposed to their final intervention (visit 3), they will be administered a questionnaire to determine if there was adequate blinding to the intervention. Participants will be reminded of the intervention protocol for each visit and asked to answer two questions. The first question asks whether the participants believed whether the intervention described was an active treatment. This will be recorded as either yes or no. The second question will ask participants to rate how certain they were that they received the active treatment on a 0–10 numeric rating scale. A score of 0 indicates absolute uncertainty whilst a score of 10 indicates absolute certainty. Adequate blinding of the intervention will be determined if participants are not able to distinguish the placebo from the true intervention.
Timepoint [6] 417623 0
30-minutes post intervention at third visit.

Eligibility
Key inclusion criteria
Eligible participants will consist of adults aged 18-55 years with non-specific chronic low back pain, defined as pain between T12 vertebra and gluteal fold, persisting for more than three months, without known specific pathology. Eligible participants will be required to have an average pain intensity rating of at least 4/10 in the prior week, which will be rated on a verbal numeric rating scale at the time of telephone screening.
Minimum age
18 Years
Maximum age
55 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
History of spinal surgery, spinal trauma, structural scoliosis, or low back pain due to non-musculoskeletal causes (e.g., infection, visceral pain) will be excluded. Other exclusion criteria include pregnancy, less than 1 year post-natal or current lactation, inability to communicate in English, being a current or prior elite athlete (i.e., a member of Australian Institute of Sport), and any absolute contraindications for exercise training.

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
A member of the research team who will have no contact with participants will generate the randomised intervention allocation sequence.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The order in which participants are exposed to the three interventions (one exposure per visit) will be randomised electronically according to the Williams randomised allocation sequence for cross-over randomised controlled trial designs (R statistical package 4.1.3, library randomizeBE).
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
Linear mixed effect models with intention-to-treat will be used to evaluate the effect of acute exercise exposure (wall squat, true control, placebo) on pressure pain thresholds and low back pain intensity. These models will include participants as random effect, and time point, intervention sequence and period as fixed effects. Differences in between group dichotomised answers to the blinding questionnaire will be examined by chi-squared test. Multiple linear regression models will be used to determine the association between kinesiophobia, disability, depression, anxiety, stress and EIH. An alpha of 0.05 will be adopted for all analyses.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
9/01/2023
Date of last participant enrolment
Anticipated
9/04/2023
Actual
Date of last data collection
Anticipated
9/05/2023
Actual
Sample size
Target
30
Accrual to date
3
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 312935 0
University
Name [1] 312935 0
Deakin University
Country [1] 312935 0
Australia
Primary sponsor type
University
Name
Deakin University
Address
1 Gheringhap St, Geelong VIC 3220
Country
Australia
Secondary sponsor category [1] 314623 0
None
Name [1] 314623 0
Address [1] 314623 0
Country [1] 314623 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 312208 0
Deakin University Human Research Ethics Committee
Ethics committee address [1] 312208 0
Ethics committee country [1] 312208 0
Australia
Date submitted for ethics approval [1] 312208 0
18/08/2022
Approval date [1] 312208 0
06/10/2022
Ethics approval number [1] 312208 0
2020-057

Summary
Brief summary
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 123850 0
Dr Clint T Miller
Address 123850 0
Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, 221 Burwood Highway, Burwood VIC 3125
Country 123850 0
Australia
Phone 123850 0
+61 03 92446605
Fax 123850 0
Email 123850 0
[email protected]
Contact person for public queries
Name 123851 0
Clint T Miller
Address 123851 0
Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, 221 Burwood Highway, Burwood VIC 3125
Country 123851 0
Australia
Phone 123851 0
+61 03 92446605
Fax 123851 0
Email 123851 0
[email protected]
Contact person for scientific queries
Name 123852 0
Clint T Miller
Address 123852 0
Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, 221 Burwood Highway, Burwood VIC 3125
Country 123852 0
Australia
Phone 123852 0
+61 03 92446605
Fax 123852 0
Email 123852 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Electronic data which is de-identified via Open Science Framework.
When will data be available (start and end dates)?
Available from completion of the study with no set end-date, etc.
Available to whom?
Anyone.
Available for what types of analyses?
Any with acknowledgement of the original trial
How or where can data be obtained?
Data will be available via Open Science Framework (https://osf.io/) or by contacting the principal investigator ([email protected]).


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.