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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Retrospectively registered

Titles & IDs
Public title
Neuroscience-inspired exercise to enhance outcomes for people with knee pain: clinical virtual reality exercise
Scientific title
Using virtual reality with exercise to assess gain change on peak knee angles: a case control study of people with and without knee pain

Secondary ID [1] 294366 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Chronic knee pain 307095 0
Condition category
Condition code
Musculoskeletal 306206 306206 0 0
Normal musculoskeletal and cartilage development and function

Study type
Description of intervention(s) / exposure
The intervention is supervised by two physiotherapists. The VR intervention is a single session and takes around 15 mins (including the rest periods) and the total testing time for the session takes approximately 1.5 hours.

The intervention consists of changing the visual gain (which is the amount people perceive they are moving compared to the real world) via virtual reality goggles during a set of 36 squats.

All participants will put on a virtual reality (VR) headset and all will complete the intervention.
While wearing the VR headset participants will complete in total 36 bilateral squats plus 3 warm up squats. They will be asked to reproduce their 50% squat depth for all 36 squats. The 50% squat depth will be established in baseline testing prior to the intervention and measured using a biomechanical marker system (VICON).

Warm up squats
In the virtual environment, participants first see a soccer stadium and complete three warm up squats to get used to moving in the virtual world (no gain change).

VR intervention
Participants will next see an office environment consisting of a floor, walls, windows, ceiling, desk and chair. In the office environment they will complete the bilateral squat intervention under different gain conditions.

The gain conditions manipulate the visual feedback to give the perception that they are moving more or less compared to the real world movement.

During the intervention, participants will be asked to squat repeatedly to their 50% squat depth. Each block consists of 4 sets of 3 squats (totalling 12 squats) with a 2 minute rest in between each block. Within the block, each set of three squats will have a gain value applied to either increase gain, no change or decrease gain. There are five possible gain options within each block (2 with gain increases, 2 with gain decreases and one no change) so that within each block of 4 sets, participants will randomly receive 4 out of the five gain conditions.

The control condition is where the change in vision in the virtual environment mimics real world movement.

Increase in gain refers to two conditions where the change in vision in the virtual environment is greater than reality (moderate increase and maximum increase).

Decrease in gain refers to two conditions where the change in vision in the virtual environment is less than in reality (moderate reduction and maximum reduction).

The order of gain condition within a block of 12 squats will be randomised, and participants will complete 3 X 12 squats in total. Participants and researchers are blinded during the intervention as to whether the gain is neutral, increased or decreased.

Following the completion of 36 squats, all participants will undergo post-session outcome measure testing including reproduction of the 50% squat depth.

Intervention code [1] 300671 0
Treatment: Devices
Comparator / control treatment
The comparator is the no gain change condition within the VR session
Control group

Primary outcome [1] 305216 0
Change in the peak knee angle of the squat movement compared with no gain change condition measured using the VICON motion analysis system.
Timepoint [1] 305216 0
During the intervention - average of the peak knee angles will be compared between the increase in gain conditions and no gain change conditions. The participants will be asked to replicate their 50% squat depth throughout all conditions.
Secondary outcome [1] 368356 0
Safety - specifically safety will be measured as the number of adverse events (defined as removal of the headset, ceasing the testing for any reason associated with VR (e.g. dizziness). Also, follow-up on if VR intervention aggravated knee pain.

Timepoint [1] 368356 0
Immediately post VR intervention - adverse events, feedback and experience questionnaire developed specifically for this study and administered verbally by the researcher

1-7 days after intervention - follow-up on knee resulting from VR intervention

Secondary outcome [2] 368357 0
Change in peak knee flexion angle measured using wearable markers and motion capture system during trials with a positive gain during squat compared to pre-exercising squat peak knee angle
Timepoint [2] 368357 0
Comparison of immediately before (50% squat depth peak knee flexion angle) and during positive gain condition of the VR intervention (peak knee flexion angle)
Secondary outcome [3] 368358 0
Change in average peak knee angle of a pain free squat measured with wearable markers and motion capture system.
Timepoint [3] 368358 0
Pre VR intervention compared with immediately post VR intervention (cases only)
Secondary outcome [4] 368359 0
Changes in the average peak knee angle of the squat movement assessed with VICON motion analysis during the decreasing gain trials compared with no gain change trials during the VR session.
Timepoint [4] 368359 0
within VR intervention - compare decrease gain with no gain change conditions
Secondary outcome [5] 371929 0
Movement/coordination variability during jumping and hopping tasks using VICON.
Participants will perform up to 20 continuous jumps and hops to determine if movement strategies change during these tasks.
Timepoint [5] 371929 0
Post VR intervention (immediately post)
Secondary outcome [6] 371946 0
joint sequencing - sequence of joint initiation during squat task measured via wearable markers and motion capture system.
Timepoint [6] 371946 0
Immediately pre intervention, during and immediately post VR intervention
Secondary outcome [7] 371947 0
Jumping and hopping tasks

Participants will be asked to complete double leg continuous jumps and single-leg hops for both right and left legs. Joint sequencing and peak angles will be compared Movements will be analysed using lower limb joint angles, range of motion and joint loading. Data will be used to compare case v controls
Timepoint [7] 371947 0
Pre-VR intervention - 10 minutes prior
Secondary outcome [8] 371948 0
Lower limb joint loading

Ankle, knee and hip joint moments and joint forces for full, 'pain-free' and 50% squat depths captured using markers and VICON motion capture system
Timepoint [8] 371948 0
Pre- (5 mins prior), during and immediately post-VR intervention
Secondary outcome [9] 371949 0
Open kinetic chain v closed kinetic chain reproduction angle v ascending and descending stair task

Participants will be asked to reproduce a knee flexion angle while seated (open kinetic chain), which will then be compared to the knee flexion angle reproduced during the 50% squat (closed kinetic chain). Knee flexion angle will also be compared to the ascending/descending stair task. Results will be compared between cases and controls. Participants wear markers throughout all testing and these data are captured via the VICON motion capture system.
Timepoint [9] 371949 0
Pre (immediately)-, during and post-VR intervention (5 mins post)
Secondary outcome [10] 372245 0
Rates of change within the joint

These are measured via wearable markers used to calculate joint velocities and accelerations (peaks and mean) during all three squat conditions.
Timepoint [10] 372245 0
Pre (5 mins prior), during and post VR intervention (immediate)
Secondary outcome [11] 373738 0
"50% squat depth" accuracy of reproduction of range of motion measured immediately post VR intervention in the real world

Assessed via wearable markers and captured on VICON motion capture system (joint angles)
Timepoint [11] 373738 0
Immediately post intervention - compared with pre-intervention 50% squat depth (pre intervention occurs 5 mins prior to intervention)
Secondary outcome [12] 373739 0
Lower limb kinematics

Hip, trunk and ankle joint angles measured via wearable markers and captured with VICON motion capture system for 50% squat depth squat condition
Timepoint [12] 373739 0
during VR
Secondary outcome [13] 377546 0
Timepoint [13] 377546 0
Feasibility will be measured based on the ease of recruitment (number of patients expressing interest and screened into the trial within the next 8 months), as well as a patient reported questionnaire regarding their feedback and experience administered immediately following the session.
Secondary outcome [14] 377547 0
Joint position sense - reproducibility of position assessed by markers on all lower limb joints
Timepoint [14] 377547 0
pre VR 50% squat depth and immediately post

Key inclusion criteria
Knee pain group
- non-traumatic chronic knee pain (> 3 months duration).
- must be able to understand and read English

No knee pain group
- no current pain or history of knee pain within past year

Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Acute knee pain (<3 months)
Vertigo or dizziness
Any neurological symptoms including numbness, pins and needles or weakness
Psychiatric illness

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
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
The software file for the virtual reality software can be pre completed so that both participant and assessor are blinded to the VR condition the participant is seeing (amount of gain). The file provides the visual scenes during the VR experience by pre-coding gain values, scene, auditory input.

This allows the person delivering the intervention to be blinded to which VR condition is being seen, and participants will be unsure of which VR condition is being seen. Data for pain are collected on an ipad allowing blinding of assessors to whether participant is a case or control, All data will be analysed blinded to case or control status.
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
For squat kinematics, knee flexion angle, ankle dorsiflexion angle, hip flexion angle and vertical head displacement will be calculated for each VR condition by taking an average of the value from the individual squats done in that VR condition. These will then be pooled by group for each of the VR conditions (no change, 2 increasing and 2 decreasing gain).

A 2 (group: knee pain and control) x 6 (pre intervention + 5 VR conditions) repeated measures ANOVA will be conducted to determine the effect of different VR conditions on on joint angle reproduction during the task. Post-hoc testing will be conducted on any significant findings.

The outcome of safety and feasibility will not require statistical analysis, and will be presented as descriptive statistics and key themes summarised from patient questionnaires.

To determine the immediate effect post intervention, the same squat kinematic measures listed above will be compared pre- and post-intervention using a two-way analysis of covariance (ANCOVA) with the baseline values as a covariate.

Pain scores and timed stair ascent will be analysed using a two-way ANCOVA with pre-intervention scores used as the covariate.

Recruitment status
Stopped early
Data analysis
Data collected is being analysed
Reason for early stopping/withdrawal
Other reasons/comments
Other reasons
Recruitment ceased slightly early due to Covid-19.
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)

Funding & Sponsors
Funding source category [1] 299008 0
Government body
Name [1] 299008 0
NHMRC - National Health and Medical Research Council
Address [1] 299008 0
16 Marcus Clarke St, Canberra ACT 2601
Country [1] 299008 0
Primary sponsor type
La Trobe University
La Trobe University
Kingsbury Drive, Plenty Road
Bundoora VIC 3086
Secondary sponsor category [1] 298233 0
Name [1] 298233 0
Address [1] 298233 0
Country [1] 298233 0

Ethics approval
Ethics application status
Ethics committee name [1] 299936 0
La Trobe University Human Research Ethics Comittee
Ethics committee address [1] 299936 0
La Trobe University
Bundoora 3086 VIC
Ethics committee country [1] 299936 0
Date submitted for ethics approval [1] 299936 0
Approval date [1] 299936 0
Ethics approval number [1] 299936 0

Brief summary
Background: Virtual reality (VR) is technology that completely immerses users in a virtual world and was originally developed for entertainment. VR games have been used during medical procedures to provide drug-free pain relief, and to increase motivation to exercise in conditions such as stroke, enabling potential new applications in rehabilitation. The enjoyment and distraction VR provides is fairly well understood, however the complex mechanisms underpinning pain relief are not.

Aims: My aims are to combine VR with exercise in a novel approach that targets different contributors to chronic knee pain; the peripheral contributions and the central contributions. This study will provide pilot data on the types of visual illusions that impact pain and movement perception.

Design: This application is to pilot the use of VR for larger scale studies, and to evaluate the visual contribution to movement and pain perception in people with and without anterior knee pain. To do this we will manipulate the amount people perceive they are moving (change in gain) compared to the real world. Participants will be asked to wear a VR headset while performing a number of squats, and will have their pain, squat depth and other clinical examination assessed.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 82042 0
Dr Ebonie Rio
Address 82042 0
La Trobe Sport & Exercise Medicine Research Centre
Kingsbury Drive, Plenty Road
La Trobe University
Bundoora VIC 3086
Country 82042 0
Phone 82042 0
+613 9479 3785
Fax 82042 0
Email 82042 0
Contact person for public queries
Name 82043 0
Dr Ebonie Rio
Address 82043 0
La Trobe Sport & Exercise Medicine Research Centre
Kingsbury Drive, Plenty Road
La Trobe University
Bundoora VIC 3086
Country 82043 0
Phone 82043 0
+613 9479 3785
Fax 82043 0
Email 82043 0
Contact person for scientific queries
Name 82044 0
Dr Ebonie Rio
Address 82044 0
La Trobe Sport & Exercise Medicine Research Centre
Kingsbury Drive, Plenty Rooad
La Trobe University
Bundoora VIC 3086
Country 82044 0
Phone 82044 0
+613 9479 3785
Fax 82044 0
Email 82044 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
What data in particular will be shared?
Only de-identified data will be made available to protect participant privacy.

All outcome measures will be made available (FIGSHARE)
When will data be available (start and end dates)?
Immediately following publication and the placed on a repository.
Estimated start date October 2020
No end date determined
Available to whom?
Any researcher who contacts the primary investigator and outlines a clear proposal as to why they would like access to the data and their aims for use of the data.
Available for what types of analyses?
The data may only be used for inclusion in meta-analyses, or for re-analysis of the data for the outcomes of this proposal.
How or where can data be obtained?
Data will only be made available once all investigators on the project have agreed to allow to make the data available for use. Data will be available on FIGSHARE or by contacting the PI Dr Ebonie Rio

La Trobe Sport and Exercise Medicine Research Centre
Kingsbury Drive
What supporting documents are/will be available?
No other documents available
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