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Trial registered on ANZCTR


Registration number
ACTRN12616000307404
Ethics application status
Approved
Date submitted
2/03/2016
Date registered
9/03/2016
Date last updated
14/08/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
Pain-free vs. pain-threshold exercise during hamstring strain injury rehabilitation
Scientific title
Pain-free vs. pain-threshold exercise during hamstring strain injury rehabilitation
Secondary ID [1] 288528 0
None
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Acute muscle strain injury 297620 0
Hamstring strain injury 297621 0
Condition category
Condition code
Musculoskeletal 297809 297809 0 0
Other muscular and skeletal disorders
Physical Medicine / Rehabilitation 298058 298058 0 0
Other physical medicine / rehabilitation

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Part A of this research project refers to the initial clinical assessment to confirm presence of acute hamstring strain injury. Once this is complete part B of the research study refers to the twice weekly clinical assessment and rehabilitation sessions. These sessions will last from 60 to 90 minutes in duration and last until the return to play criteria are successfully met. This criteria includes pain-free palpation of the injury site, pain-free range of motion assessment, pain-free isometric knee flexor strength assessment and pain-free sprinting.

The rehabilitation includes resistance exercise and progressive running up to a limit of participant rated pain-threshold of 4/10 on a visual analogue scale (VAS). Rehabilitation sessions will be fully supervised by an accredited exercise physiologist on an individual basis. Rehabilitation sessions will consist of progressive running protocol which includes 3 stages, walk-jog-walk, jog-run-jog and run-sprint-run. These intensities are rated by the participant's perception of running intensity based on the following jog = less than 50% intensity, run = 70% intensity and sprint = 100% intensity. Each of these stages contains 3 levels starting with 20m acceleration, 10m constant speed, 20m deceleration with these levels progressing to 15m-20m-15m and finally 10m-30m-10m. Participants will progress to the next level once they have completed 3 repetitions at the previous level within the limits of 4/10 pain on the VAS. Participants are permitted to complete a maximum of 9 repetitions per session.

Following the progressive running protocol participants will complete resistance exercises including a supine hamstring bridge 3*10-15 repetitions, 45 degree hip extension 3*8-10 repetitions, eccentric sliding hamstring curl 3*4-6 repetitions and the Nordic hamstring exercise 3*4-6 repetitions. Each exercise will be progressed on an individual basis within the limits of 4/10 pain on the VAS. The Nordic hamstring exercise will only commence once the eccentric sliding hamstring curl can be completed with the limits of 4/10 pain on the VAS. These sessions will take place twice per week with a minimum of one days rest in between sessions for recovery. Adherence will be essential as completing rehabilitation sessions twice per week is required for participation in this research project. This will be monitored during each session as the participant will be attending ACU twice per week so the date and session number will be recorded on a spreadsheet at the start of each visit and everything they do during that session recorded on the same spreadsheet.
Intervention code [1] 293900 0
Rehabilitation
Comparator / control treatment
Participants randomly allocated to the pain-free group will complete the identical rehabilitation protocol as outlined above with the only difference being the guidelines for progression being within the limits of 0/10 pain on the VAS scale.
Control group
Active

Outcomes
Primary outcome [1] 297569 0
Hamstring muscle strength which will be objectively measured using externally-fixed load cells during isometric knee flexor contractions, an eccentric sliding hamstring curl and the Nordic hamstring exercise.
Timepoint [1] 297569 0
Measures will be taken twice per week during each clinical assessment/rehabilitation session participants complete until the time of return to normal activity clearance. These measures will also be taken again during a follow up clinical assessment conducted 2 months after clearance for normal activity.
Primary outcome [2] 297570 0
Days taken from the initial injury to return to normal activity clearance. Return to normal activity clearance is given once all the following are met during clinical assessment, pain-free palpation of the injury site, pain-free range of motion assessment and pain-free isometric strength assessment and pain-free sprinting.
Timepoint [2] 297570 0
At the time of return to normal activity clearance which is determined based upon evidence based criteria as outlined above.
Primary outcome [3] 297593 0
Hamstring muscle architecture which will be measured via 2 dimensional ultrasound by an experienced sonogropher.
Timepoint [3] 297593 0
Muscle architecture will be measured twice per week during each clinical assessment participants complete until the time of return to normal activity clearance. This will also be taken again during a follow up clinical assessment conducted 2 months after clearance for normal activity.
Secondary outcome [1] 321412 0
Subsequent rates of re-injury which will be monitored via self-reporting from the participant which will be confirmed by clinical assessment given the participant's availability for 24 months following their initial injury. Participants will also be contacted by the research team on a weekly basis to check whether they have had any suspected re-injury.
Timepoint [1] 321412 0
Participants will be invited to attend weekly clinical assessments to monitor progress until 3 months post return to normal activity clearance. In addition telephone and email contact will be made weekly with the participant until 24 months post return to normal activity clearance to check for any subsequent re-injuries. If the participant suspects re-injury they will be invited to attend ACU for a clinical assessment to determine prescence of re-inury.
Secondary outcome [2] 321413 0
Fear of exercise due to pain as measured via the Tampa scale of kinesiophobia.
Timepoint [2] 321413 0
The Tampa scale will be completed during the initial clinical assessment, at the time of return to normal activity clearance and again at 2 month follow up clinical assessment.

Eligibility
Key inclusion criteria
Individuals with an acute hamstring strain injury defined as the acute onset of posterior thigh pain during activity causing the individual to stop what they are doing. This injury must confirmed by clinical assessment within seven days of the initial injury incident.
Minimum age
18 Years
Maximum age
40 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Individuals presenting with posterior thigh pain with no acute mechanism or onset. Other causes of posterior thigh pain such as proximal hamstring tendinopathy, referred pain due to lumbar spine pathology will be excluded. Individuals with complete hamstring muscle ruptures (grade 3) or avulsion fracture injuries requiring surgery will also be excluded from participation.

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)
Sealed envelopes containing the details of either pain-free or pain-threshold exercise guidelines.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?


The people assessing the outcomes
Intervention assignment
Parallel
Other design features
Phase
Type of endpoint(s)
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC

Funding & Sponsors
Funding source category [1] 293034 0
University
Name [1] 293034 0
Australian Catholic University
Address [1] 293034 0
115 Victoria Parade, Fitzroy, Victoria 3065
Country [1] 293034 0
Australia
Primary sponsor type
University
Name
Australian Catholic University
Address
115 Victoria Parade, Fitzroy, Victoria 3065
Country
Australia
Secondary sponsor category [1] 291809 0
None
Name [1] 291809 0
Address [1] 291809 0
Country [1] 291809 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 294545 0
Australian Catholic University Human Research Ethic Committee
Ethics committee address [1] 294545 0
c/o Office of the Deputy Vice Chancellor (Research)
Australian Catholic University
North Sydney Campus
PO Box 968
NORTH SYDNEY, NSW 2059
Ethics committee country [1] 294545 0
Australia
Date submitted for ethics approval [1] 294545 0
19/11/2015
Approval date [1] 294545 0
29/01/2016
Ethics approval number [1] 294545 0
2015-307H

Summary
Brief summary
The aims of this research project are to determine how hamstring muscle function and structure change over time during rehabilitation for hamstring strain injury and whether exercising completely pain-free or to a pain-threshold effects the time course of these changes. The research project is split into two parts, part A is a cohort study to determine presence of acute hamstring strain injury and part B is a randomised control trial. We will recruit recreationally active males and females who suspect they have suffered an acute hamstring strain injury for part A of the study until we have recruited forty participants with clinically confirmed acute hamstring strain injury within seven days of initial suspected injury for part B of the study.

Part A of the study involves a one off initial clinical assessment including a subjective interview, inspection of the injury site, assessments of muscle structure, strength and flexibility to determine presence of acute hamstring strain injury. If acute hamstring strain injury is confirmed within seven days of initial suspected injury, participants will be eligible to participate in part B of the study and randomised to either a pain-free or pain-threshold exercise group. Both groups in part B of the study will complete identical follow-up clinical assessments and rehabilitation including progressive running and resistance exercise twice per week until pre-determined return to play criteria is met. Participants in the pain-free group must complete all exercises and running within the rehabilitation protocol completely pain-free and if any level of pain in caused during rehabilitation, exercises will be altered appropriately. Participants in the pain-threshold group will be allowed to exercise and run to a pain-threshold of 4/10 on a visual analogue scale (VAS) and if any level of pain greater than this is experienced during rehabilitation, exercises will be adjusted accordingly. Once these criteria have been met, participants will be free to resume their previous level of activity and invited to attend ACU on a weekly basis for follow-up clinical assessment as above for a period of 3 months. During this period and the subsequent 24 months following return to play clearance, participants will be contacted on a weekly basis to enquire whether any suspected re-injury has occurred. In this event participants will be required to attend a follow-up clinical assessment to confirm presence of re-injury and if confirmed they may be eligible for additional rehabilitation services.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 63502 0
Dr David Opar
Address 63502 0
School of Exercise Science, Australian Catholic University, Melbourne Campus 115 Victoria Parade, Fitzroy, Victoria 3065
Country 63502 0
Australia
Phone 63502 0
+61 3 9953 3742
Fax 63502 0
Email 63502 0
david.opar@acu.edu.au
Contact person for public queries
Name 63503 0
Mr Jack Hickey
Address 63503 0
School of Exercise Science, Australian Catholic University, Melbourne Campus 115 Victoria Parade, Fitzroy, Victoria 3065
Country 63503 0
Australia
Phone 63503 0
+61 432 225 273
Fax 63503 0
Email 63503 0
jack.hickey@acu.edu.au
Contact person for scientific queries
Name 63504 0
Mr Jack Hickey
Address 63504 0
School of Exercise Science, Australian Catholic University, Melbourne Campus 115 Victoria Parade, Fitzroy, Victoria 3065
Country 63504 0
Australia
Phone 63504 0
+61 432 225 273
Fax 63504 0
Email 63504 0
jack.hickey@acu.edu.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary