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Trial registered on ANZCTR

Registration number

ACTRN12618000894291

Ethics application status

Approved

Date submitted

22/05/2018

Date registered

28/05/2018

Date last updated

13/10/2020

Date data sharing statement initially provided

27/11/2018

Type of registration

Prospectively registered

Titles & IDs

Public title

Effects of exercises for the low back muscles on disability in people with chronic low back pain

Scientific title

Effects of lumbar extensor muscle strengthening and neuromuscular retraining on disability in patients with chronic low back pain

Secondary ID [1]

None

Universal Trial Number (UTN)

U1111-1214-3373

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Chronic low back pain

Condition category

Condition code

Musculoskeletal

Other muscular and skeletal disorders

Physical Medicine / Rehabilitation

Physiotherapy

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

The intervention group will attend two, 30-minute exercise sessions per week over a 12-week period. All exercise sessions will be supervised by physiotherapists and exercise physiologists who are experienced in delivering strengthening exercises to people with chronic low back pain. These sessions will be conducted as a one-on-one.

The intervention group will complete both strengthening and neuromuscular retraining exercises. A description of both follows:

i) Neuromuscular exercise:
For neuromuscular retraining exercises, participants will be seated on a MedX dynamometer with their trunk in 12 degrees of flexion and lower limbs fixed in order to restrict posterior pelvic rotation and other lower limb movements. Using their lumbar extensor muscles, participants will be required to push back into the pad placed at the level of their thoracic spine and match a fluctuating target force varying between 20-50% of their lumbar extension maximal voluntary isometric contraction (MVIC; Pranata et al., 2017). This target force, as well as a real-time measure of the participant's force, will be displayed on a tablet placed one meter in front of the participant.

Participants will perform this force matching task at 0.08 Hz (medium speed) for 60 seconds as a warm-up. Participants will then perform three, 60-second force matching sets at three different frequencies: i) 0.08 Hz (5 waves per minute; as per the warm-up), ii) 0.14 Hz (8.4 waves per minute; fast speed) and, iii) 0.05 Hz (3 waves per minute; slow speed). The order of the three frequencies will be random. Participants will receive 30 seconds rest between the warm-up and each of the three sets performed at different frequencies.

The parameters for progression of this exercise over the 12-week intervention include:
i) The amplitude of the target wave, whilst remaining at 20-50% MVIC, will change according the MVIC value assessed at the beginning of each training session.
ii) The duration of the sets will increase from 60 to 90 seconds at the beginning of week 5 (the warm-up set will remain the same). Set duration will increase again from 90 to 120 seconds at the beginning of week 7 and the duration will not increase for the remainder of the trial.
iii) At the beginning of week 9, each set will incorporate the three frequencies, rather than single frequencies in isolation for each set. Frequencies will vary randomly and will change throughout the 120 seconds.

ii) Strength exercise:
In addition to the neuromuscular exercise described above, the intervention group will also complete global (i.e., whole body) and isolated (i.e., lumbar extensor muscles) strengthening exercises. Four of the strengthening exercises will be standardised across both the intervention and control groups. Standardised exercises include lumbar extension (using the MedX), hip extension, leg press and trunk flexion. At their discretion, treating clinicians can incorporate other strength exercises into the interventional program which will be documented in training logs.

Of the standardised strengthening exercises, participants will complete the lumbar extension (using the MedX dynamometer) and one of the other three listed exercises each session, at the discretion of the treating clinician.

Adherence to the intervention will be monitored via an exercise record taken by the treating clinician. Treating clinicians will contact participants who miss an exercise session, within 2 days. Missed appointments will be documented.

Intervention code [1]

Rehabilitation

Intervention code [2]

Treatment: Other

Comparator / control treatment

The control group will attend two 30-minute exercise sessions per week over a 12 week period. As per the intervention group, the exercise sessions will be supervised by physiotherapists and exercise physiologists who are experienced in delivering strengthening exercises to people with chronic low back pain. These sessions will be conducted as a one-on-one.

The control group will only complete the four standardised strengthening exercises as described in the intervention section and any other strengthening exercise delivered by the clinician at their discretion. They will not complete the neuromuscular exercise described in the intervention section.

Of the standardised strengthening exercises, participants will complete the lumbar extension (using the MedX dynamometer) and one of the other three listed exercises each session, at the discretion of the treating clinician.

Adherence to the intervention will be monitored via an exercise record taken by the treating clinician. Treating clinicians will contact participants who miss an exercise session, within 2 days. Missed appointments will be documented.

Control group

Active

Outcomes

Primary outcome [1]

Oswestry Disability Index

Scored using 10 sections about pain and function, with varying response options for each section. Score range for each section is 0 to 5. Overall scores are calculated into percentages ranging from 0 to 100%; higher percentages indicate worse disability.

Timepoint [1]

Baseline, 6 and 12 weeks (primary endpoint) after randomisation

Secondary outcome [1]

Pain Self-Efficacy Questionnaire

Scored using 10 questions about confidence regarding pain and physical activity, with Likert response options ranging from Not at all confident to Completely confident. Scores range from 0 to 60; lower scores indicate less confidence.

Timepoint [1]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [2]

Tampa Scale for Kinesiophobia

Scored using 17 questions about fear of pain and/or movement, with Likert response options ranging from Strongly disagree to Strongly agree. Scores range from 17 to 68; higher scores indicate greater fear avoidance behaviours.

Timepoint [2]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [3]

Lumbar extension force accuracy

Assessed isometrically using a MedX machine at 12o trunk flexion. Participants will attempt to match a sub-maximal, fluctuating extension force trace.

Timepoint [3]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [4]

Lifting kinematics

Measures of multiple joint rage of movement, angular velocity, movement coordination and mean relative phase angles and deviation will be taken during lifting of an 8kg weight.

Movement analysis and three-dimensional mapping of anatomical landmarks will be performed using an optoelectric motion analysis system (Optitrack Flex 13, NaturalPoint, Corvalis, OR) at a sampling rate of 120 Hz.

Timepoint [4]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [5]

Lifting kinetics

Measuring vertical ground reaction force during lifting of an 8kg weight.

Balance and force distribution through each lower limb will be assessed using Nintendo Wii Balance BoardsTM (WBB, Nintendo, Kyoto, Japan).

Timepoint [5]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [6]

Muscle thickness of iliocostalis lumborum

Measured via ultrasound images acquired of iliocostalis lumborum. Measured using Image J from superficial fascial border to deep muscle border. Images will be taken at rest and during a prone active straight leg raise to determine difference in muscle morphology with muscle contraction.

Timepoint [6]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [7]

Muscle echogenicity of iliocostalis lumborum

This qualitative analysis of muscle will be derived from the US images acquired of iliocostalis lumborum measured using ImageJ. Measurement be performed by tracing within the border of the muscle and calculating pixel density

Timepoint [7]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [8]

Pain severity

Scored on an 11-point Numeric Rating Scale for average overall pain in the last week. Ranges from 0 to 10; where 0=no pain and 10=worst pain possible.

Timepoint [8]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [9]

Isometric lumbar extension strength

Isometric lumbar extension torque, seated at 12 degrees of lumbar flexion (i.e., neutral upright sitting). Measured using a MedX dynamometer.

Timepoint [9]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [10]

Co-intervention use

Participants will complete a custom-developed questionnaire to indicate the type, number and frequency (over the past 6 months) of co-interventions used.

Timepoint [10]

Baseline, and 12 weeks post randomisation

Secondary outcome [11]

Adverse events

An adverse event is defined as any fall, injury or muscle soreness as a result of the study that impacts participation in exercises. Serious adverse events resulting in life threatening and permanently disabling injuries will be recorded on a separate form.

Adverse events will be patient reported. Adverse events will be documented by treating clinicians and the assessor depending on when the event occurred and who the participant reported it to.

Timepoint [11]

Throughout the study

Secondary outcome [12]

Adherence

An exercise diary recorded by treating Kieser physiotherapists.

Timepoint [12]

Each training session (twice per week)

Secondary outcome [13]

International Physical Activity Questionnaire (IPAQ) – Short Form

Scored using 7 questions about physical activity levels in the past week

Timepoint [13]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [14]

Muscle thickness of lumbar multifidus

Measured via ultrasound images acquired of lumbar multifidus. Measured using Image J from superficial fascial border to deep muscle border. Images will be taken at rest and during a prone active straight leg raise to determine difference in muscle morphology with muscle contraction.

Timepoint [14]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [15]

Muscle echogenicity of lumbar multifidus

This qualitative analysis of muscle will be derived from the US images acquired of lumbar multifidus measured using ImageJ. Measurement be performed by tracing within the border of the muscle and calculating pixel density

Timepoint [15]

Baseline, 6 and 12 weeks post randomisation

Secondary outcome [16]

Medication use

Participants will complete a custom-developed questionnaire to indicate the type, number and frequency (over the past 6 months) of medication used.

Timepoint [16]

Baseline, and 12 weeks post randomisation

Eligibility

Key inclusion criteria

i) aged between 18 and 65 years;
ii) report recurrent low back pain with or without pain radiating into the lower limbs for at least three months;
iii) demonstrate moderate or greater disability on the Oswestry Disability Index (i.e., 21% or greater).

Minimum age

18 Years

Maximum age

65 Years

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

i) medication managed psychological illness
i) diagnosed psychiatric illness such as depression or anxiety;
ii) previous spinal and lower limb surgery;
iii) diagnosed spinal osteoporosis/osteopaenia;
iv) diagnosed unstable spondylolysthesis/spondylolysis;
v) diagnosed active systemic/inflammatory joint disease;
vi) diagnosed neurological and developmental disorders;
vii) overt neurological sign (absence of lower limb reflex or motor paralysis);
viii) diagnosed significant medical conditions such as cancer or major cardiac diseases;
ix) history of abdo-pelvic organ prolapse;
x) use of medications that may influence balance;
xi) patients funded by a compensable body (TAC, WorkCover etc.);
xii) inability to understand written/spoken English;
xiii) pregnant;
xiv) <6 months post-partum.

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)

The primary researcher who is responsible for deeming eligibility for inclusion into the trial will not be privy to which group that participant will be allocated at the time when eligibility is being determined. Once eligibility is determined, participant details are sent to an off-site researcher not involved in recruitment, treatment or assessment of participants. This off-site researcher will randomly allocate the participants to the intervention or control group, then inform the treating clinicians of the participants group allocation (i.e. allocation involved contacting the holder of the allocation schedule who was "off-site".)

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

The method for sequence generation will be permuted block randomisation. The randomisation schedule will be prepared by the biostatistician stratified by Oswestry Disability Index (ODI) severity (i.e., moderate or severe/greater). The schedule will be stored on a password-protected document maintained by a researcher not involved in either participant recruitment, administration of primary/secondary outcome measures or participant treatment/exercise delivery.

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

The people receiving the treatment/s

The people assessing the outcomes
The people analysing the results/data

Intervention assignment

Parallel

Other design features

Phase

Not Applicable

Type of endpoint/s

Efficacy

Statistical methods / analysis

The aim is to detect a 10-point difference in the primary outcome (i.e., Oswestry Disability Index (ODI)), which corresponds to the minimal clinically important difference (MCID; Ostelo et al., 2008). With a standard deviation of 15, this difference corresponds to an effect size of 0.67, and the between-group ODI MCID can be detected with 80% power and a significance level of 0.05 with 37 participants per group. Allowing for 20% drop-out, recruitment of 47 (=37/(1-0.2)) participants per group is required.

The Principal Investigator will analyse blinded data under the supervision of a biostatistician (Dr Jessica Kasza, Dept of Epi & Preventive Medicine, Monash Uni). Main comparative analyses between groups will be performed using intention-to-treat. If the proportion of missing outcome data is greater than 5%, multiple imputations will be used to account for missing outcome data. Data missing at baseline will be imputed using single mean imputation. Complete-case analyses will also be conducted. For the primary hypothesis, differences in mean change in disability index (baseline minus follow-up) will be compared between groups using linear regression modelling adjusted for baseline values and the stratifying variable of ODI level. Similar analyses will be conducted for continuous secondary outcomes. Standard diagnostic plots will be used to check the model assumptions of linearity, and of constant variance and normality of residuals

Recruitment

Recruitment status

Stopped early

Data analysis

Data collected is being analysed

Reason for early stopping/withdrawal

Safety concerns

Date of first participant enrolment

Anticipated

12/06/2018

Actual

23/07/2018

Date of last participant enrolment

Anticipated

1/04/2020

Actual

18/03/2020

Date of last data collection

Anticipated

1/07/2020

Actual

18/03/2020

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

VIC

Recruitment postcode(s) [1]

3186 - Brighton

Funding & Sponsors

Funding source category [1]

University

Name [1]

University of Melbourne

Address [1]

Centre for Health Exercise and Sports Medicine
Department of Physiotherapy
School of Health Sciences
The University of Melbourne
Level 7, Alan Gilbert Building
Building 104, 161 Barry St
Parkville VIC 3010

Country [1]

Australia

Funding source category [2]

Commercial sector/Industry

Name [2]

Kieser Training Victoria Pty Ltd

Address [2]

5B North St
Ascot Vale VIC 3032

Country [2]

Australia

Primary sponsor type

Individual

Name

Mr Joshua Farragher

Address

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

University of Melbourne Behavioural and Social Sciences Human Ethics Sub-Committee

Ethics committee address [1]

Research Ethics & Integrity
The University of Melbourne
Level 1, 21 Bedford St,
North Melbourne VIC 3051

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

20/07/2017

Approval date [1]

08/08/2017

Ethics approval number [1]

1749845

Summary

Brief summary

Chronic low back pain (CLBP) is the leading cause of disability worldwide (Hoy et al., 2014). In 2015, approximately 540 million or 7.3% of the world’s population had activity limiting low back pain (Hartvigsen et al., 2018; Global Burden of Disease, 2016). In Australia, 3.7 million people (16% of the overall population) suffer from CLBP each year (AIHW, 2015).

Exercise treatments are common Australian physiotherapy practice for people with CLBP; however, current evidence does not demonstrate that one type of exercise is superior to another (Hayden et al., 2005; Saragiotto et al., 2016; Wang et al., 2012). This is partly attributed to the fact that the mechanism(s) contributing to exercise-related improvements in CLBP are unknown. Therefore, this research is critically important for understanding the effects and underlying mechanisms of exercise interventions for people with CLBP.

We are conducting a research study to compare the effects of neuromuscular and strengthening exercises to strengthening exercises alone on CLBP-related disability. To do this we will allocate people via a random process into two different groups. Participants in each group will complete a 12-week strengthening exercise program. Participants in the intervention group will, in addition to strengthening exercises, complete a neuromuscular exercise. Participants will not be disclosed as to which group they are in until the end of the program. There will be an equal number of participants in each group, and participants will not be able to choose which group they are in.

The findings of this study will help to determine what effects strengthening and neuromuscular exercises have on CLBP-related disability, and mechanism of improvements. This will provide clinicians with an evidence base for the prescription of strength and neuromuscular exercises when treating CLBP-related disability. The findings of this study will be published in peer-reviewed medical and physiotherapy journals and be presented at national and international conferences.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Mr Joshua Farragher

Address

Country

Australia

Phone

+61383440422

Fax

[email protected]

Contact person for public queries

Name

Joshua Farragher

Address

Country

Australia

Phone

+61383440422

Fax

[email protected]

Contact person for scientific queries

Name

Joshua Farragher

Address

Country

Australia

Phone

+61383440422

Fax

[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?

Patient reported outcomes, including disability, pain, pain self-efficacy and fear avoidance beliefs. Strength, force accuracy, muscle size and simple lifting biomechanics data.

When will data be available (start and end dates)?

At the completion of the trial - anticipated for 01/10/2019 until 01/01/2020

Available to whom?

The participants upon request

Available for what types of analyses?

No analysis

How or where can data be obtained?

E-mail

What supporting documents are/will be available?

Doc. No.	Type	Citation	Link	Email	Other Details	Attachment
532	Ethical approval					375040-(Uploaded-27-11-2018-12-41-18)-Study-related document.pdf

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

Source	Title	Year of Publication	DOI
Embase	Effects of lumbar extensor muscle strengthening and neuromuscular control retraining on disability in patients with chronic low back pain: A protocol for a randomised controlled trial.	2019	https://dx.doi.org/10.1136/bmjopen-2018-028259

N.B. These documents automatically identified may not have been verified by the study sponsor.

Trial Review

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