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Trial registered on ANZCTR


Registration number
ACTRN12615000240549
Ethics application status
Approved
Date submitted
23/02/2015
Date registered
17/03/2015
Date last updated
17/03/2015
Type of registration
Retrospectively registered

Titles & IDs
Public title
The effect of leg compression garments on the mechanical performance of single-leg hopping in healthy male volunteers
Scientific title
The effect of leg compression garments on the mechanical characteristics and performance of single-leg hopping in healthy male volunteers.
Secondary ID [1] 286213 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
fatigue 294258 0
Condition category
Condition code
Musculoskeletal 294574 294574 0 0
Normal musculoskeletal and cartilage development and function
Physical Medicine / Rehabilitation 294682 294682 0 0
Physiotherapy

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Full lower limb compression Skins (Trade Mark) garment were worn and included both legs. Single-leg hopping was performed on the dominant leg only. Each garment was fitted according to the manufacturer guidelines and not to a pre-determined pressure in mmHg to ensure a correctly fitted garment. Skins TM do not disclose the ideal pressure range that their garments apply to the wearer. However, this range is reported to be built into their garment sizing system which is based on a Body Mass Index - anthropometrical algorithm Skins TM have developed. Participants in this study were fitted with garments according to the manufacturer’s sizing system. Thus, the findings from the current investigation are consistent with the manufacturer’s recommended garment sizing guidelines.
The garment was worn once only for the duration of the single-leg hopping effort with the garment. The task required the participant to perform on-the-spot, single-leg hopping on the self-selected dominant leg in synchrony with an audible metronome (2.2 Hz), on an instrumented forceplate to volitional exhaustion, when the participant could no longer continue to hop at the required cadence due to experiencing calf muscle fatigue or was unable to maintain their position on the forceplate. There was a 10 minute wash out period betwen the three efforts (no garment, garment and sham) of single-leg hopping.
Intervention code [1] 291232 0
Prevention
Comparator / control treatment
Sham treatment condition (tape adhered on the skin overlying the muscle bellies of the quadriceps femoris and calf muscles)

control condition - no garment and no sham
Control group
Placebo

Outcomes
Primary outcome [1] 294345 0
Duration of hopping measured by the time stamp recorded by the instrumented forceplate from the start of the first hop cycle to the end of the last hop cycle.
Timepoint [1] 294345 0
After completion of the task of hopping for each condition.
Secondary outcome [1] 313076 0
Vertical leg stiffness was determined by calculating the quotient of force and vertical height displacement. Vertical force was recorded from an instrumented force plate and was the change in vertical ground reaction force (vGRF) from initial contact (first recorded force >10N) to peak vertical vGRF (loading phase).
Vertical height displacement during loading phase (from initial contact to peak vGRF) was calculated using the law of falling bodies. First, vertical displacement during the second half of flight phase (zf) was calculated,
zf = 0.5 x g x (0.5 x tf)^2 (Equation 1)
where g was the acceleration due to gravity (9.81 m.s-1) and tf was the duration of flight phase. This method assumes that the velocity of the COM at the peak height during flight phase was 0 m.s^-1 as there was a change in direction of the COM that occurred at half flight phase.
The velocity at IC was then determined by the following equation,
vi = (2 x g x zf)^0.5 (Equation 2)
Where vi was the velocity at IC, g was the acceleration due to gravity (9.81 m.s^-2) and zf was vertical displacement of the COM during the second half of flight phase.
Vertical displacement of the COM during loading phase (zl) from IC to peak vGRF was then calculated using the following equation
zl=0.5(vi+vf) x tl (Equation 3)
where zl was the vertical displacement of the COM during loading phase, vi was the velocity at IC, vf was velocity at peak vertical ground reaction force and assumed to be 0 m.^s-1 and tl was the duration of loading phase.
Thus, vertical leg stiffness (k) was calculated,
k = vGRF/zl
Timepoint [1] 313076 0
Start (first 10 consecutive hop cycles) and end (last 10 consecutive hop cycles) of the hopping task for each condition
Secondary outcome [2] 313503 0
Spatiotemporal characteristics of the centre of mass (duration of flight and contact phases and vertical displacement of the centre of mass during flight and loading phases of hopping). Temporal characteristics were determined from the recorded vertical ground reaction force (vGRF) data for each hop cycle and included the duration of flight time (from toe-off to initial contact (IC)); loading phase (from IC to peak vGRF); contact phase (from IC to toe-off) and hop cycle (sum of flight and contact phases). Toe-off and IC were identified for each hop cycle as the first recorded value >10N when there was a consistent decline or rise from baseline force (~0N) during the flight phase.
Spatial characteristics were determined from the law of falling bodies which included the vertical displacement of the centre of mass (COM) during the second half of flight phase (zf); vertical displacement of the COM during loading phase (zl). The equations for calcualtion of zf and zl are provided in the description of the primary outome (equations 1 and 3).
Timepoint [2] 313503 0
Start (first 10 consecutive hop cycles) and end (last 10 consecutive hop cycles) of the hopping task for each condition

Eligibility
Key inclusion criteria
Recreationally active (3-15 hours of exercise participation per week)
Minimum age
18 Years
Maximum age
35 Years
Gender
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
Pain or injury of the lower limb or spine on the day of testing or in the 6 months prior to testing

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
All volunteer participants provided written and informed consent prior to the commencement of testing and were informed that they could withdraw from the study at any time during the testing procedure.
This was a repeated measures design such that all participants were exposed to all three conditions of hopping; with a garment, with a sham and without a sham or garment in a random order.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The participant chose one of three marked cards (face down) to determine the order of the conditions of hopping.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
A repeated measures analysis of variance was performed to determine differences between conditions and time peridos for the dependant variables. A minimum sample size of N=28 was required as determeind by G*Power (V 1.0) with significance accepted at p<0.05 and power (1-beta) was 0.8 and a small effect size (0.25).
A total of N=38 were included in the study. An assumption of repeated measures ANOVA is that the dependant variable is normally distributed (Hills, 2008). However, when N is large (>30) the paired t-test is robust (analogous to a repeated measure) and the violation of the normality assumption has little effect on its accuracy (Hills, 2008).

Reference
Adelma Hills (2008). Foolproof guide to statistics using SPSS (3rd Ed). Pearson Education Australia.

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)
NSW
Recruitment postcode(s) [1] 9246 0
2560 - Campbelltown

Funding & Sponsors
Funding source category [1] 290780 0
University
Name [1] 290780 0
University of Western Sydney, School of Biomedical and Health Sciences
Address [1] 290780 0
University of Western Sydney
Narellan Road
Campbelltown Campus
Campbelltown
NSW 2560
Country [1] 290780 0
Australia
Funding source category [2] 290849 0
Commercial sector/Industry
Name [2] 290849 0
Skins (trade mark) (In kind supply of garments)
Address [2] 290849 0
Skins Compression Garments Pty Ltd
PO Box 268
Riverwood
NSW 2210
Australia
Country [2] 290849 0
Australia
Primary sponsor type
University
Name
University of Western Sydney
Address
University of Western Sydney
Narellan Road
Campbelltown Campus
Campbelltown
NSW 2560
Country
Australia
Secondary sponsor category [1] 289479 0
None
Name [1] 289479 0
Address [1] 289479 0
Country [1] 289479 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 292411 0
University of Western Sydney Human Ethics Research Committee
Ethics committee address [1] 292411 0
Univeristy of Western Sydney
Locked Bag 1797
Penrith
NSW 2751
Ethics committee country [1] 292411 0
Australia
Date submitted for ethics approval [1] 292411 0
Approval date [1] 292411 0
04/04/2011
Ethics approval number [1] 292411 0
CHS 040411-02

Summary
Brief summary
The purpose of this investigation was to determine the effect of compression garments on performance and vertical stiffness during single-leg-hopping to exhaustion. The alternate hypothesis was that compression garments would lead to a change in the duration of single-leg hopping and leg mechanical characteristics.
Trial website
N/A
Trial related presentations / publications
Bryers, J. J., Clothier, P. J., & Gupta, A. (2011). An evaluation of the effect of graded compression garments on temporal and mechanical characteristics during a single leg hopping. Conference Proceedings of the 8th Australasian Biomechanics Conference, Canberra, Australia, Nov 28 – 29, 2011.
Public notes

Contacts
Principal investigator
Name 55102 0
Dr Peter Clothier
Address 55102 0
University of Western Sydney
School of Science and Health
Narellan Road
Campbelltown Campus
Bldg 24, level 2, Room
Campbelltown
NSW 2560
Country 55102 0
Australia
Phone 55102 0
+61246203792
Fax 55102 0
Email 55102 0
p.clothier@uws.edu.au
Contact person for public queries
Name 55103 0
Dr Peter Clothier
Address 55103 0
University of Western Sydney
School of Science and Health
Narellan Road
Campbelltown Campus
Bldg 24, level 2, Room
Campbelltown
NSW 2560
Country 55103 0
Australia
Phone 55103 0
+61246203792
Fax 55103 0
Email 55103 0
p.clothier@uws.edu.au
Contact person for scientific queries
Name 55104 0
Dr Peter Clothier
Address 55104 0
University of Western Sydney
School of Science and Health
Narellan Road
Campbelltown Campus
Bldg 24, level 2, Room
Campbelltown
NSW 2560
Country 55104 0
Australia
Phone 55104 0
+61246203792
Fax 55104 0
Email 55104 0
p.clothier@uws.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