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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Exploring hamstrings flexion-relaxation phenomenon in experimental low back pain
Scientific title
Does experiential low back pain in normal healthy participants change the hamstring flexion-relaxation response?
Secondary ID [1] 282732 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Low back pain 289466 0
Condition category
Condition code
Musculoskeletal 289779 289779 0 0
Other muscular and skeletal disorders

Study type
Description of intervention(s) / exposure
Two injections of 0.4 ml of hypertonic saline in lumbar erector spinae muscles (3 cm from mid-line) will be injected to induce experimental low back pain; one in the right lumbar ES and the other in left lumbar ES.
Intervention code [1] 287461 0
Treatment: Other
Comparator / control treatment
Data will be collected in healthy individual before and after inducement of pain with hypertonic saline injections in lumbar erector spinae muscles
Control group

Primary outcome [1] 289863 0
Measurement of electrical activity (EMG) in hamstring muscles during trunk flexion with experimental pain to lumbar erector spinae
Timepoint [1] 289863 0
At each phase of trunk flexion before and after injection of hypertonic saline
Primary outcome [2] 289864 0
Range of lumbar flexion by taking photographs from side and measuring angle of lumbar flexion by using a software (Image J)
Timepoint [2] 289864 0
While standing erect and in full flexion position both before and after injection of hypertonic saline
Secondary outcome [1] 303607 0
Timepoint [1] 303607 0

Key inclusion criteria
Age 18-55 years
Ability to give written, informed consent
Minimum age
18 Years
Maximum age
55 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Orthopedic or neurological disorders of low back or thigh
Pain on the day of testing
Use of pain medication on the day of testing
Recent trauma to lower back or leg
Unusually elevated hamstring muscle activity which manifests as limited lumbopelvic rotation (assessed on case-by-case basis)
Any pain related condition may be grounds for exclusion
Score >24 on Pain Catastrophising Scale (PCS)
Somatic hypervigilance as indicated by score >7 on Modified Somatic Pain Questionnnaire (MSPQ)
Diagnosis of hemophilia or other clotting disorders
Allergy to latex products
Non New Zealand citizens or residents (due to insurance issues)

Study design
Purpose of the study
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Single group
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis

An estimated effect size of 1.7 was used from Zedka’s research for power calculations with alpha at 0.05 and beta at 0.8 which provided required sample of 5 participants. Given response in hamstring muscles is not expected to be as pronounced as that of lumbar erector spinae muscles, target sample was doubled to 10.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 5163 0
New Zealand
State/province [1] 5163 0

Funding & Sponsors
Funding source category [1] 287506 0
Name [1] 287506 0
Unitec Institute of Technology, New Zealand
Address [1] 287506 0
139 Carrington Road, Mt Albert
Country [1] 287506 0
New Zealand
Primary sponsor type
139 Carrington Road, Mt Albert
New Zealand
Secondary sponsor category [1] 286244 0
Name [1] 286244 0
Address [1] 286244 0
Country [1] 286244 0

Ethics approval
Ethics application status
Ethics committee name [1] 289482 0
Unitec Research Ethics Committee (UREC)
Ethics committee address [1] 289482 0
139 Carrington Road
Mt. Albert, Auckland 1025
Ethics committee country [1] 289482 0
New Zealand
Date submitted for ethics approval [1] 289482 0
Approval date [1] 289482 0
Ethics approval number [1] 289482 0

Brief summary
This study will identify if experimentally induced lumbar erector spinae muscle pain will affect the activity of the hamstring muscles during a standardised trunk flexion task.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 41030 0
Mr Gajanan Deshmukh
Address 41030 0
Gajanan Deshmukh
Unitec Institute of Technology
3/12 Quona Avenue
Mt. Roskill
Auckland 1041
Country 41030 0
New Zealand
Phone 41030 0
+64 9 6264692
Fax 41030 0
Email 41030 0
Contact person for public queries
Name 41031 0
Mr Gajanan Deshmukh
Address 41031 0
Gajanan Deshmukh
Unitec Institute of Technology
3/12 Quona Avenue
Mt. Roskill
Auckland 1041
Country 41031 0
New Zealand
Phone 41031 0
+64 9 6264692
Fax 41031 0
Email 41031 0
Contact person for scientific queries
Name 41032 0
Mr Jamie Mannion
Address 41032 0
Jamie Mannion
Unitec Institute of Technology
Building 41, room 1018
139 Carrington Road
Mt. Albert, Auckland 1025
New Zealand
Country 41032 0
New Zealand
Phone 41032 0
Fax 41032 0
Email 41032 0

No information has been provided regarding IPD availability
Summary results
No Results