Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12609000181202
Ethics application status
Approved
Date submitted
15/12/2008
Date registered
17/04/2009
Date last updated
17/04/2009
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effects of tendon vibration on quadriceps muscle activation in anterior cruciate ligament reconstructed and arthritic populations.
Scientific title
The effects of tendon vibration on quadriceps muscle activation in anterior cruciate ligament reconstructed and arthritic populations.
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Anterior cruciate ligament (ACL) reconstruction 4133 0
Knee osteoarthritis 4134 0
Condition category
Condition code
Musculoskeletal 4331 4331 0 0
Osteoarthritis
Surgery 4332 4332 0 0
Other surgery

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Part A. 15 ACL reconstructed and 15 age and gender matched controls and 15 subjects with knee osteoarthritis and 15 age and gender matched controls will have their infrapatellar tendon vibrated (50Hz) for 20 minutes while seated in a chair. Three maximum voluntary contractions of the quadriceps and three maximum voluntary contractions of the hamstrings will be performed before and then again after vibration.

Part B. 3-7 days later, the same subjects will have their infrapatellar tendon vibrated at 4 different frequencies (0Hz, 5Hz, 80Hz, 200Hz) during maximum voluntary contractions of their quadriceps. Three maximum voluntary contractions will be performed at each frequency, in a random order. A 2 minute rest period will be given between each contraction.
Intervention code [1] 3844 0
Treatment: Other
Intervention code [2] 3845 0
Diagnosis / Prognosis
Comparator / control treatment
Part B. A 0Hz (control) and 5Hz (placebo) frequency will be used
Control group
Active

Outcomes
Primary outcome [1] 5217 0
Normalised quadriceps peak torque (Newton metres/Body weight)
Timepoint [1] 5217 0
Part A. Before and after 20 minute vibration period.

Part B. During vibration (4 different frequencies of vibration)
Secondary outcome [1] 8784 0
Root mean square of electromyographic signals recorded from the quadriceps and hamstrings muscles
Timepoint [1] 8784 0
Part A. Before and after 20 minute vibration period.

Part B. During vibration (4 different frequencies of vibration)
Secondary outcome [2] 241569 0
Normalised peak hamstrings torque (Newton metres/body weight)
Timepoint [2] 241569 0
Part A. Before and after 20 minute vibration period.

Eligibility
Key inclusion criteria
Participants in the ACL reconstructed group should have had an ACL reconstruction in the last 4-24 months using a semitendinosus gracilis graft.

Participants in the osteoarthritis group will have radiologically diagnosed osteoarthritis of the knee with a kellgren lawrence score of greater than or equal to 2.
Minimum age
16 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Control subjects who volunteer but have a history of injury or pathology in either knee joint may be excluded

Participants from all groups may be excluded if they have a history of spinal surgery, low back pain in the last 6 months with associated neurological signs and symptoms or any systemic disease that prevents them from participating in maximum strength testing.

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)
ACL reconstructed and OA patients will be recruited from physiotherapy and orthopaedic practices in the Auckland area. In addition, advertisements will be put in local newspapers and posters placed around AUT University’s City and North Shore campuses asking for volunteers to participate in the study. All participants will receive the same interventions. Allocation is not concealed as all participants will receive the vibration intervention in part B. The order of vibration frequencies (i.e. 0Hz, 5Hz, 80Hz, 200Hz) will be randomised for each participant using computerised random number generation.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Computerised sequence generation
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
5/12/2008
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
60
Accrual to date
Final
Recruitment outside Australia
Country [1] 1475 0
New Zealand
State/province [1] 1475 0
Auckland

Funding & Sponsors
Funding source category [1] 4299 0
Government body
Name [1] 4299 0
Accident Compensation Corporation
Country [1] 4299 0
New Zealand
Primary sponsor type
Government body
Name
Health Research Council
Address
110 Stanley Street Auckland 1010
Country
New Zealand
Secondary sponsor category [1] 3871 0
None
Name [1] 3871 0
Address [1] 3871 0
Country [1] 3871 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 6345 0
AUT University Ethics Committee
Ethics committee address [1] 6345 0
55 Wellesley St East Auckland 1010
Ethics committee country [1] 6345 0
New Zealand
Date submitted for ethics approval [1] 6345 0
Approval date [1] 6345 0
18/11/2008
Ethics approval number [1] 6345 0
07/231

Summary
Brief summary
Joint disease often leads to an ongoing, reflex weakness of muscles acting across the damaged joint. This process is thought to occur at a spinal cord level and is called Arthrogenic Muscle Inhibition (AMI). Several neural pathways may contribute to AMI, one of which is the gamma loop. To investigate the functional significance of the gamma loop, a number of authors have used prolonged muscle or tendon vibration to experimentally attenuate the excitability of muscle spindle nerve fibres. Vibration artificially enhances muscle spindle activity for short periods but when vibration is sustained for longer than 10-20 seconds spindle firing is progressively diminished, reducing the transmission of Ia afferent input to the spinal cord. With a 20 minute period of vibration, transmission of Ia afferent input is blocked for 10-20 minutes after vibration ceases. In healthy subjects, prolonged tendon vibration has been shown to cause a reduction in muscle activity, motor unit firing rates and contraction force during maximum strength contractions. However, in patients who have ruptured their ACL, prolonged vibration has no effect on quadriceps force output or muscle activity, suggesting a pre-existing deficit in the transmission of muscle spindle input to quadriceps alpha motoneurons in the spinal cord. This deficit has been termed gamma loop dysfunction and has been shown to persist after ACL reconstruction, contributing to quadriceps AMI that is often observed in these patients. However, it remains unknown whether gamma-loop dysfunction contributes to quadriceps AMI in patients with knee osteoarthritis. This study will explore the effects of prolonged (20 minutes) vibration (Part A) and short-duration (5 second) vibration on quadriceps and hamstrings muscle activation. It is hypothesised that immediately after prolonged tendon vibration quadriceps torque and electromyography will be significantly reduced in the healthy control subjects but not in the ACL reconstructed and osteoarthritis groups, indicating gamma-loop dysfunction. It is further hypothesised that short duration tendon vibration will significantly enhance quadriceps torque and electromyography in the ACL reconstructed and osteoarthritis groups but not in healthy control subjects.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 35042 0
Address 35042 0
Country 35042 0
Phone 35042 0
Fax 35042 0
Email 35042 0
Contact person for public queries
Name 12389 0
David Rice
Address 12389 0
Health and Rehabilitation Research Centre
AUT University
Private Bag 92006
Auckland
1010
Country 12389 0
New Zealand
Phone 12389 0
+64 99219999 ext. 7032
Fax 12389 0
Email 12389 0
[email protected]
Contact person for scientific queries
Name 3317 0
David Rice
Address 3317 0
AUT University
Private Bag 92006
Auckland
1010
Country 3317 0
New Zealand
Phone 3317 0
+64 99219999 ext. 7032
Fax 3317 0
Email 3317 0
[email protected]

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What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

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