Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12619000550101
Ethics application status
Approved
Date submitted
2/04/2019
Date registered
9/04/2019
Date last updated
9/04/2019
Date data sharing statement initially provided
9/04/2019
Date results information initially provided
9/04/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
Thermal imaging to measure muscle activity during and soreness following exercise.
Scientific title
Can thermal infrared imaging detect skin temperature changes associated with delayed onset of muscle soreness in healthy volunteers?
Secondary ID [1] 297868 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
delayed onset muscle soreness 312242 0
Condition category
Condition code
Musculoskeletal 310789 310789 0 0
Normal musculoskeletal and cartilage development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Experimental overview
The study followed a within-participant design, requiring volunteers to visit the laboratory on four occasions. The initial visit (5–7 d before visit two) involved a comprehensive neuromuscular testing familiarisation. The second visit involved resting thermal images of the right and left anterior thighs, and maximal voluntary contraction (MVC) testing before and after an intense exercise protocol designed to induce acute muscle damage and delayed onset of muscle soreness (DOMS). Visits 3–4 involved a thermal image, and an MVC test. Testing was balanced for morning-afternoon, and within a participant all testing was performed at the same time of day (±1 hr). All testing was administered by an accredited exercise physiologist (AEP).

Initial testing session
Height and mass were recorded and participants completed the pre-exercise screening questionnaire (Exercise and Sports Science Australia Adult Pre-Exercise Screen Tool). After a standardised warm up (WU; see neuromuscular section), individuals completed multiple-sets of 5 s isometric MVC’s during which twitch interpolation was applied. Participants were considered familiarised after achieving a plateau in MVC torque for a full set (5 x 5 s) of contractions. On average familiarisation took 7 sets (range: 3–9). During the initial visit, participants were also familiarised to the perceptual soreness, session rating of perceived exertion (sRPE) and modified profile of mood states ‘POMS’ measures. Perceived soreness was rated on a 0 ‘no soreness’ to 10 ‘extremely sore’ visual analogue scale. The modified POMS comprised six-states (‘active’, ‘energetic’, ‘restless’, ‘fatigued’, ‘exhausted’, and ‘alert’) rated on a 1–5 Likert scale, which ranged from 0 ‘low’ to 5 ‘high’. POMS states were summed, providing a global indication of mood ‘Mood’. Session rating of perceived exertion (sRPE) was collected 10 min after exercise.
Participants were given specific instructions for the days leading up to their first testing session so to ensure adequate preparation of thermal image skin sites. Namely, (a) avoid prolonged sun exposure five days prior to testing to prevent sun burn; (b) if applicable, remove hair from the anterior and posterior aspects of both thighs 36 hr before testing to prevent inflammation and/or skin surface damage (c) avoid exercise, caffeine and alcohol in the 24 hr prior to testing; and (d) avoid hot showers, ointments and cosmetics on each testing day.

Thermal images
Two thermal infrared cameras were utilised to assess resting (A305sc, FLIR Systems, Wilsonville, Orego, USA) and exercising (PI450, Optris Gmbh, Berlin, Germany) skin temperature. Measurements were undertaken in temperature-controlled, fluorescently lit rooms without the existence of electric heat generators, wind drafts or external radiation sources. Prior to the resting images being collected the participant rested for 20 min in a seated position in order to acclimate to the temperature of the room. Resting thermal images, with the FLIR camera, were then conducted with camera positioning (relative to participant), stabilisation, emissivity and image processing as previously reported (Bach AJ, Stewart IB, Disher AE, Costello JT. A comparison between conductive and infrared devices for measuring mean skin temperature at rest, during exercise in the heat, and recovery. PLoS One. 2015;10(2):e0117907). The exercising thermal images were conducted with the Optris camera mounted on a portal frame, downward looking and parallel with the anterior thigh regions while the participant was seated on the dynamometer. The distance between camera and the anterior surface of the thigh was set to 1.2 m to ensure both right and left thighs were in the field of view of the camera simultaneously. Data sampling and image processing were as previously reported (Moghadam P, editor 3D medical thermography device. SPIE Sensing Technology + Applications; 2015: SPIE; Vidas S, Moghadam P, Sridharan S. Real-Time Mobile 3D Temperature Mapping. IEEE Sensors Journal. 2015;15:1145-52).

Neuromuscular function
Neuromuscular function was assessed via maximal voluntary contraction (MVC) and evoked twitch properties of the right knee extensors using a Biodex isokinetic dynamometer (Systems 3, Biodex Medical Systems, New York, USA). Participants were seated in an upright position, chair backrest adjusted to 95° from the horizontal plane, and tightly secured with waist, shoulder, hip and thigh straps. The lateral epicondyle of the femur was aligned with the axis of rotation of the dynamometer, and the right knee was positioned at 90°, with 0° being full extension. The lower leg was firmly strapped to the lever arm, approximately 2 cm above the lateral malleolus of the ankle. Before testing, participants completed 15 isometric knee extension WU contractions, 5 at 40% perceived maximal effort, 5 at 60%, 3 at 80% and 2 at 90%, with 10 s rest between each contraction.
Muscle activation of the right knee extensors was achieved by percutaneous stimulation of the femoral nerve using a self-adhesive electrode (anode, 3.2 cm diameter; Pals, Axelgaard Manufacturing Co. Ltd., Fallbrook, USA). A second electrode was placed on the border of the gluteal fold (cathode, 5 x 9 cm; Pals, Axelgaard Manufacturing Co. Ltd., Fallbrook, USA). During MVC, a single square-wave pulse width of 100 µs (400 V with a current of 400–700 mA) was delivered via a stimulator (DS7AH; Digitimer Ltd., Welwyn Garden City, England) at 120% of maximal peak twitch torque. The required current was determined via a twitch ramp procedure commencing at 50 mA, thereby increasing 50 mA every 30 s until a plateau in peak (evoked) twitch torque was achieved. Within ~2 s following MVC a second stimulus was delivered to examine muscle contractile properties. To maximise voluntary activation and enhance motivation, strong verbal encouragement and visual force feedback was provided during MVC’s.
Neuromuscular data were sampled at 1,000 Hz and recorded into LabChart (LabChart 8.0; AD Instruments, Sydney, Australia) via a PowerLab system (16-bit PowerLab 26T; AD Instruments, Sydney, Australia). Maximal voluntary torque was considered the mean value in the 25 ms period preceding the electric stimuli. Superimposed torque was considered the peak value in the 100 ms after the stimuli. The level of voluntary activation (VA) was determined for each MVC using the twitch interpolation technique, with VA calculated as: VA (%) = [(1-superimposed twitch/potentiated twitch)*100]. MVC repetitions were excluded from analysis if: (1) no plateau prior to stimulation was achieved; (2) the superimposed stimulus was delivered at a sub-maximal force; or (3) stimulation occurred at a non-maximal effort. Peak twitch torque, rate of torque development (RTD), contraction time (CT), and half-relaxation time (HRT) were determined for each twitch response, and alterations in these properties were used to infer acute muscular fatigue, and the presence of DOMS.

Exercise protocol
Following the pre-exercise MVC test (MVC 1), participants undertook an intense single-leg exercise protocol consisting of a series of maximal concentric (CON) and eccentric (CON) contractions of the right knee extensors. Participants were seated upright and secured as per MVC testing. The protocol involved 6 sets of 25 maximal CON/ECC contractions at an angular velocity of 60 (CON) and 120°·s-1 (ECC), performed within a range of 15° to 80° knee flexion, with 0° being full knee extension. A 5 min rest period separated each set. A similar exercise protocol has previously been shown to induce acute muscle fatigue and DOMS in resistance trained male athletes (Pointon M, Duffield R, Cannon J, Marino FE. Cold application for neuromuscular recovery following intense lower-body exercise. Eur J Appl Physiol. 2011;111(12):2977-86). Participants were instructed to provide maximal effort across the range of each CON/EEC contraction. Loud verbal encouragement was provided throughout, and visual force feedback was displayed on a computer monitor situated 1.5 m in front of the dynamometer. Five min after protocol completion post-exercise MVC (MVC 2) testing was performed, and 10 min after exercise votes of sRPE and soreness were collected.

Follow-up testing
Participants returned to the laboratory 24 hr and 48 hr following the baseline testing session. Subjective scales of muscle soreness and POMS were collected and right thigh girth was assessed (F10-02DM, KDS, Malaysia). Following a 30 min acclimation period, thermal images of both thighs were conducted before undertaking the MVC protocol. Approximately 10 min after the MVC protocol a sRPE was collected.
Intervention code [1] 314100 0
Early detection / Screening
Comparator / control treatment
Each participant acted as their own control; with their right leg undertaking the exercise protocol and the left leg acting as the control comparison.
Control group
Active

Outcomes
Primary outcome [1] 319634 0
Resting skin temperature as assessed by A305sc, FLIR Systems, Wilsonville, Orego, USA
Timepoint [1] 319634 0
Skin temperature was assessed at 24 and 48 hours following the exercise protocol and compared with baseline (pre-exercise).
Primary outcome [2] 319680 0
Exercising skin temperature as assessed by PI450, Optris Gmbh, Berlin, Germany
Timepoint [2] 319680 0
Exercising skin temperature was assessed at baseline during the exercise protocol.
Secondary outcome [1] 368942 0
Neuromuscular function
Neuromuscular function was assessed via maximal voluntary contraction (MVC) and evoked twitch properties of the right knee extensors using a Biodex isokinetic dynamometer (Systems 3, Biodex Medical Systems, New York, USA).
Timepoint [1] 368942 0
Neuromuscular function was assessed at 24 and 48 hours after the exercise protocol and compared with baseline.
Secondary outcome [2] 369008 0
Perceived soreness
Perceived soreness was rated on a 0 ‘no soreness’ to 10 ‘extremely sore’ visual analogue scale.
Timepoint [2] 369008 0
Perceived soreness was assessed at 24 and 48 hours after the exercise protocol and compared with baseline.
Secondary outcome [3] 369009 0
Profile of mood states (POMS)
The modified POMS comprised six-states ‘active’, ‘energetic’, ‘restless’, ‘fatigued’, ‘exhausted’, and ‘alert’) rated on a 1–5 Likert scale, which ranged from 0 ‘low’ to 5 ‘high’. POMS states were summed, providing a global indication of mood ‘Mood’.
Timepoint [3] 369009 0
Profile of mood states (POMS) was assessed at 24 and 48 hours after the exercise protocol and compared with baseline.
Secondary outcome [4] 369010 0
Right thigh girth.
Assessed with a tape measure (F10-02DM, KDS, Malaysia)
Timepoint [4] 369010 0
Baseline, post 24 and 48 hours.
Secondary outcome [5] 369071 0
Session rating of perceived exertion (sRPE).
Assessed using the Borg categorical 10 point scale where 0 represents "complete rest" and 10 "extremely hard".
Timepoint [5] 369071 0
Session rating of perceived exertion (sRPE) was conducted 10 minutes after completion of exercise at baseline, 24 and 48 hours.

Eligibility
Key inclusion criteria
Healthy participants that are classified as moderately trained (a minimum 6 months training history of at least 2 strength and/or endurance sessions per week) will be recruited to participate in this study.
Minimum age
18 Years
Maximum age
45 Years
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
History, or current existence of any knee injury, cardiopulmonary disease, acute skin conditions (e.g. adhesive tape allergy), any metabolic, arterial, venous or lymphatic pathology, current history of smoking, or the use of any medication that may alter thermoregulation.

Study design
Purpose of the study
Diagnosis
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
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis
Data were analysed using linear mixed-effects models in a Bayesian framework. Model factors were time (neuromuscular variables, ambient temperature, soreness, sRPE, POMS, thigh girth) or time, leg and time x leg (skin temperature). Models included a random intercept term for each participant in the study. When skin temperature was the response variable, ambient temperature was included as a standardised covariate. Vague prior distributions were used for skin and ambient temperature, soreness, sRPE, Mood and thigh girth. This was achieved by setting a mean of 0 and precision of 0.001 for each regression coefficient (beta), and a shape of 0.01 and scale of 0.01 for the variance parameters. For neuromuscular variables, informative priors were utilised for the beta corresponding to the baseline pre-exercise time point (i.e., the intercept), with the prior mean and precision setting: MVC torque (234, 0.004), VA (93.7, 0.082), peak twitch torque (63, 0.002), RTD (808, 0.000013), contraction time (141, 0.001), and HRT (62, 0.002). Vague priors were employed for remaining beta’s and the variance parameters. Prior information was drawn from (Borg DN, Stewart IB, Costello JT, Drovandi CC, Minett GM. The impact of environmental temperature deception on perceived exertion during fixed-intensity exercise in the heat in trained-cyclists. Physiology & Behavior. 2018;194:333-40.), who utilised the same MVC protocol employed by the current study, in a similar participant group with varied histories of lower-limb strength training. The decision to employ informative priors for neuromuscular variables was based on outcomes from posterior predictive checks.
Markov chain Monte Carlo (MCMC) procedures were used to generate posterior estimates of expected variable values. Estimates were based on 50,000 MCMC iterations (thinned by a factor of 10) after discarding an initial burn-in of 1,000 iterations. The following posterior estimates were of interest: (1) the mean and (1 – alpha)% credible interval (CI) for a measure of interest, where alpha was set to .05; (20); (2) the mean difference (MD) and associated 95% CI between time points and/or legs where statistical effects were observed, i.e., sufficient evidence the 95% CI for a beta did not include zero; and (3) Cohen’s d [denominator: square root variance ("dkl"), where ‘"dkl" is the difference between time points or legs ‘k’ and ‘l’] and associated 95% CI for the standardised difference (Mengersen KL, Drovandi CC, Robert CP, Pyne DB, Gore CJ. Bayesian Estimation of Small Effects in Exercise and Sports Science. PLoS One. 2016;11(4):e0147311.), with d values interpreted as small 0.2, medium 0.5, and large 0.8 (Cohen J. Statistical power analysis for the behavioral sciences: Routledge; 1988.). For the primary outcome variable of skin temperature, we also calculated: (1) the probability that d exceeded the ‘smallest worthwhile change’, specified as a medium effect (0.5), and denoted by Prd >SWC or Prd < -SWC depending on the direction of the difference (Mengersen KL, Drovandi CC, Robert CP, Pyne DB, Gore CJ. Bayesian Estimation of Small Effects in Exercise and Sports Science. PLoS One. 2016;11(4):e0147311.); and (2) the probability that the absolute difference in pre-exercise skin temperature exceeded 0.5 °C, denoted by PrTSK >0.5 °C or PrTSK < -0.5 °C.
Model parameters and data are reported as the mean (95% CI lower and upper bound). The convergence of the MCMC to the posterior distribution was visually assessed via trace plots. Posterior predictive checks were performed to assess the suitability of the chosen models. Bayesian models were implemented using the ‘rjags’ and ‘R2jags’ packages in the statistical software R (Lunn D, Spiegelhalter D, Thomas A, Best N. The BUGS project: Evolution, critique and future directions. Stat Med. 2009;28(25):3049-67., 23; Plummer M, Best N, Cowles K. CODA: Convergence Diagnosis and Output Analysis for MCMC. R News. 2006;6(7-11)).

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
Actual
19/06/2017
Date of last participant enrolment
Anticipated
Actual
25/07/2017
Date of last data collection
Anticipated
Actual
27/07/2017
Sample size
Target
8
Accrual to date
Final
8
Recruitment in Australia
Recruitment state(s)
QLD

Funding & Sponsors
Funding source category [1] 302391 0
Government body
Name [1] 302391 0
Commonwealth Scientific and Industrial Research Organisation
Country [1] 302391 0
Australia
Primary sponsor type
Individual
Name
Prof Ian Stewart
Address
Institute of Health and Biomedical Innovation, 60 Musk Ave, Kelvin Grove, Queensland, 4059
Country
Australia
Secondary sponsor category [1] 302282 0
Individual
Name [1] 302282 0
Dr Peyman Moghadam
Address [1] 302282 0
Robotics and Autonomous Systems, Data61, CSIRO, 1 Technology Court, Pullenvale, Brisbane, Queensland, 4069
Country [1] 302282 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 303064 0
Queensland University of Technology Human Ethics Review Committee
Ethics committee address [1] 303064 0
Office of Research Ethics and Integrity
GPO Box 2434 QLD 4000
Ethics committee country [1] 303064 0
Australia
Date submitted for ethics approval [1] 303064 0
21/02/2017
Approval date [1] 303064 0
24/03/2017
Ethics approval number [1] 303064 0
1700000140

Summary
Brief summary
Unaccustomed muscular exercise can result in delayed onset muscle soreness (DOMS). DOMS is commonly associated with changes in the type or amount of exercise being performed and is a normal response to an appropriate exercise training program. The soreness results from the muscle remodelling itself to deal with the new exercise demand. Symptoms of DOMS can range from muscle tenderness to severe debilitating soreness. This soreness leads to the perception of functional impairment, along with reductions in muscular strength and power. The intensity of these symptoms and the related discomfort increases within the first 24 hours following exercise, and peaks between 24 to 72 hours post exercise. Assessment of DOMS currently consists of invasive measures or subjective scales. An accurate, non-invasive and objective measure by which DOMS could be observed and quantified would provide great insight into recovery interventions, load monitoring, injury prevention and ensuring optimum athletic performance.
Muscle contraction and muscle remodelling results in the generation of heat. Measuring muscle temperature is an invasive and impractical procedure. However the heat that is generated within the muscle is subsequently transferred to the skin surface to be dissipated into the air, enabling skin temperature assessment to be utilised as a potential surrogate marker of muscle temperature.
Therefore, the aims of this investigation are to utilise two novel thermal imaging cameras (HeatWave and HeatStand) to 1) attempt to quantify muscle activity through skin surface temperature fluctuations; and 2) compare and contrast with the current tools for DOMS assessment.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 92338 0
Prof Ian Stewart
Address 92338 0
Institute of Health and Biomedical Innovation, Queensland University of Technology,
60 Musk Ave, Kelvin Grove, QLD 4059
Country 92338 0
Australia
Phone 92338 0
+61 7 3138 6118
Fax 92338 0
Email 92338 0
[email protected]
Contact person for public queries
Name 92339 0
Prof Ian Stewart
Address 92339 0
Institute of Health and Biomedical Innovation, Queensland University of Technology,
60 Musk Ave, Kelvin Grove, QLD 4059
Country 92339 0
Australia
Phone 92339 0
+61 7 3138 6118
Fax 92339 0
Email 92339 0
[email protected]
Contact person for scientific queries
Name 92340 0
Prof Ian Stewart
Address 92340 0
Institute of Health and Biomedical Innovation, Queensland University of Technology,
60 Musk Ave, Kelvin Grove, QLD 4059
Country 92340 0
Australia
Phone 92340 0
+61 7 3138 6118
Fax 92340 0
Email 92340 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
individual participant data, after de-identification, underlying published results only
When will data be available (start and end dates)?
Immediately following publication, no end date
Available to whom?
anyone who wishes to access it
Available for what types of analyses?
any purpose
How or where can data be obtained?
access subject to approvals by Principal Investigator


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

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No additional documents have been identified.