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Trial registered on ANZCTR


Registration number
ACTRN12618001403224
Ethics application status
Approved
Date submitted
10/08/2018
Date registered
21/08/2018
Date last updated
21/08/2018
Type of registration
Retrospectively registered

Titles & IDs
Public title
Fatigue and perceived comfort of occupational footwear
Scientific title
Fatigue musculoskeletal pain and perceived comfort during prolonged standing and physical work using different footwear options: A randomised controlled trial
Secondary ID [1] 294125 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Neuromuscular fatigue 306731 0
Condition category
Condition code
Musculoskeletal 305830 305830 0 0
Other muscular and skeletal disorders

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
The participants will be required to stand on both feet within a confined area of 900 mm / 600 m at a work bench for 4 h. During each 1-hour period the participants will perform three other activities intermittently (every 10-min) as part of the intervention (See below for intervention activities). At the end of each 1-hour interval a test battery will be conduced assessing muscle activity (EMG) during standing, perceived boot comfort, walk gait, balance, muscle stiffness, plantar flexor force production and muscle function (excitation-contraction coupling efficiency).
The intervention activities consist:
Standing – stand on two feet within 900 m / 600 mm area whilst completing non-physical work such as watching movies on computer/tablet, surfing the internet or studying.

1-min step-ups – 1 min of step ups at frequency of 88 bpm onto 40 cm box using alternate legs to step up and then down (i.e. simulate stair walking and other tasks requiring leg work).

6 x lift load from floor – lift load (2 x 5-kg dumbbells for men and 2 x 2.5-kg dumbbells for women) from floor using safe lifting technique to a standing position then replace load on floor at a rate of one lift-and-replace every 5 s (total time = 30 s).

300 m walk – walk at self-selected speed for 300 m; speed during first walk will be recorded and repeated for each individual on every walk occasion.

Participants will drink 300 ml of water in each of the first and second 2-hour periods of the intervention, and a standard, small meal will be given after the completion of the test battery performed at the 2-hour mark of the intervention.

Each participant will partake in three testing sessions each separated by a minimum of 72 h. In each individual session a different pair of steel cap work boots will be worn. Either the Steel Blue Argyle (model 312102), Steel Blue Southern Cross Zip (312661) or Blacksmith Sparky (804-80733).

All sessions will be conducted by an experienced sport science researcher with 4 years experience.
Intervention code [1] 300405 0
Prevention
Intervention code [2] 312126 0
Treatment: Devices
Comparator / control treatment
Boots with different characteristics will be compared. A ‘Control’ (CON) or comparison boots will be identified by footwear experts at Steel Blue footwear. Two experimental (EXP1 and EXP2) boots will be compared to CON, the Southern Cross Zip and Argyle.
Control group
Active

Outcomes
Primary outcome [1] 304886 0
Perceived (dis)comfort and pain

Comfort (discomfort) and pain ratings will be obtained through use of a visual analogue scale. On a 100-mm line, participants will draw a short vertical line in order to indicate their level of discomfort or pain, with ‘0’ corresponding to zero comfort (maximum discomfort) and pain, and ‘100’ corresponding to the most comfort or pain imaginable. Visual analogue scales are used extensively in research with a high reliability in order to record participant perceptions. Ratings will be obtained for the following:
1. Perceived discomfort of the boot during two-leg standing without support
2. Perceived pain in the feet (considering both feet together) for the (i) whole foot, (ii) instep, (iii) plantar surface (arch), (iv) rear foot (heel), (v) top of fore-foot (metatarsus), and (vi) toes (phalanges)
3. Perceived musculoskeletal pain (both sides of body together) of the (i) lower legs, (ii) hips, (iii) lower back, and (iv) shoulders and neck
Timepoint [1] 304886 0
Comfort (discomfort) will be assessed at 0, 1, 2, 3 and 4 (primary time point) hours throughout the intervention
Secondary outcome [1] 343480 0
Muscle activity during standing (electromyography)

Muscle activation during prolonged standing will be assessed using surface electromyography (EMG). Pairs of EMG electrodes will be placed on lower leg (soleus, tibialis anterior), hip (gluteus medius), abdominal (rectus abdominis) and lower back (erector spinae) muscles. These muscles have been shown to reveal the greatest activation changes with fatigue during prolonged standing, and/or are associated with lower back pain during standing.
Timepoint [1] 343480 0
Muscle activity will be assessed at 0, 1, 2, 3 and 4 hours throughout the intervention
Secondary outcome [2] 343481 0
Self-selected gait speed (6-m walk test)

Self-selected gait speed (6-m walk test) will be assessed using timing gates and a Zeno walkway pressure measurement system

Timepoint [2] 343481 0
Self-selected gait speed will be assessed at 0, 1, 2, 3 and 4 hours throughout the intervention
Secondary outcome [3] 343482 0
Balance

Single-leg balance testing with eyes closed on dominant leg will be done with the participant standing for 30 s on one leg in the centre of a force platform. Muscle activity, balance time and displacement of the centre of pressure from the force plate (CoP variability) will be recorded.
Timepoint [3] 343482 0
Balance will be assessed at 0, 1, 2, 3 and 4 hours throughout the intervention
Secondary outcome [4] 343483 0
Cognitive performance (memory, reasoning, spatial awareness)

Cognitive performance can be accurately and reliably measuring using computer-based tools (e.g. www.cambridgebrainsciences.com), adapted from paper/card tests that have been extensively tested for reliability and validity.

Memory – Digit span test
The participant must remember and then recall a series of numbers that appear sequentially on the computer screen. Once all numbers have been displayed, a beep will sound to indicate for the participant to type the numbers using the keyboard in the sequence in which they appeared. If the participant answers correctly then the next list will include one additional number, however one less number will be included in the list if the answer is incorrect. The participant is allowed three errors, and the best score (longest list of numbers correctly recalled) will indicate the participant’s short-term memory score.

Reasoning – Double trouble
Three words appear on the screen, one at the top and two at the bottom. The words are written in one of two colours and also spell one of the two colours. The participant must click on the word at the bottom of the screen the describes the colour used to write the word at the top of the screen, e.g. if the word at top of screen is written in blue, then the participant should click on the word ‘blue’ at the bottom of the screen irrespective of the colour in which the word is written. The participant must make as many correct decisions in 90 s as possible.

Spatial awareness – Concentration A: Rotations
Two boxes, with smaller red or green squares in a pattern inside, appear on the screen. The participant must determine whether the two boxes would be identical or not if they could rotate one of the panels clockwise or anticlockwise by choosing ‘match’ or ‘mismatch’. After a correct answer, the problem becomes more difficult, but if an incorrect answer is given then the next problem is easier. The participant is scored on how many correct answers are given in 90 s.
Timepoint [4] 343483 0
Cognitive performance will be assessed at 0 and 4 hours throughout the intervention
Secondary outcome [5] 343484 0
Ankle plantar flexor strength and rate of force development

The participant will have their right ankle firmly attached to the plantar flexion attachment of the isokinetic dynamometer with the centre of rotation of the ankle joint aligned with the dynamometer’s axis of rotation. With the ankle set in the neutral position (0°), the participant will perform 3-s isometric warm-up contractions at 30, 50 and 70% of perceived maximum. They will then perform three maximal 3-s plantar flexion contractions separated by 15 s of passive rest with the instruction to contract “as fast and then as hard as possible”. The highest reading will be taken as the maximum isometric ankle plantar flexion strength, and the maximal rate of force development will be calculated post-hoc.

Timepoint [5] 343484 0
Ankle plantar flexor strength and rate of force development will be assessed at 0, 1, 2, 3 and 4 hours throughout the intervention
Secondary outcome [6] 343485 0
Neurological and muscular function

Assessment of the maximum and rate of muscle activity, recorded using electromyography (EMG), will be assessed for the soleus muscles during the maximal plantar muscle contractions performed in 'outcome 5'. This technique will be used to determine whether the nervous systems ability to drive the muscles is compromised throughout the intervention
Timepoint [6] 343485 0
Neurological and muscular function will be assessed at 0, 1, 2, 3 and 4 hours throughout the intervention
Secondary outcome [7] 343486 0
Muscle stiffness will be measured at the calf region using a Myoton Pro device. The calf measurement will occur whilst lying prone on a massage table with the ankle at 90 degrees.
Timepoint [7] 343486 0
Immediately before the muscle strength tests at 0, 1, 2, 3 and 4 hours throughout the intervention
Secondary outcome [8] 343488 0
Muscle fatigue

Changes in the muscle’s ability to produce forceful contractions independent of the level of activation by the nervous system can be assessed by directly activating the muscles using neuromuscular electrical stimulation. Stimulating electrodes will be placed over the motor point and distal regions of the plantar flexor muscle group (calf muscles). A constant-current stimulator will be used to deliver three different types of stimuli (20Hz, 80Hz and variable frequency trains). These will then be used to determine if the efficiency of calcium release into the muscle as well as the muscles sensitivity to that calcium changes throughout the intervention
Timepoint [8] 343488 0
Immediately following the muscle strength tests at 0, 1, 2, 3 and 4 hours throughout the intervention
Secondary outcome [9] 350579 0
Movement pattern- Movement pattern will be assessed using a Zeno walkway pressure measurement system
Timepoint [9] 350579 0
Self-selected gait speed will be assessed at 0, 1, 2, 3 and 4 hours throughout the intervention
Secondary outcome [10] 350581 0
Muscle stiffness will be measured at the lower back region using a Myoton Pro device. The lower back measurement will occur whilst lying prone on a massage table
Timepoint [10] 350581 0
Immediately before the muscle strength tests at 0, 1, 2, 3 and 4 hours throughout the intervention

Eligibility
Key inclusion criteria
Male or female, aged 18 – 40 years, healthy, BMI 18-35 kg/m2, low-moderate physical activity level, not completing prescribed athletic training programs, no current musculoskeletal injury

All participants must complete a medical health questionnaire to ensure their safe participation in any study.

Minimum age
18 Years
Maximum age
40 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
1. Contraindication to exercise according to the medical health questionnaire, and in agreement with Exercise and Sports Science Australia (ESSA) and American College of Sports Medicine (ACSM) guidelines
2. Currently perform large amounts of structured physical activity, either as part of sports or occupational participation (level of exclusion to be determined for each study)
3. Alcohol > 14 drinks per week (average)
4. Smoking (or only having stopped smoking within the last 2 years)
5. T-score bone mineral density (BMD) at either the hip or lumbar spine < -2.5
6. Have any fixations (i.e. spine or femoral rods, hip replacements)
7. Planning to become pregnant or currently breastfeeding
8. Anti-inflammatory use (including aspirin, ibuprofen, omega 3)
9. Use of beta blockers or ACE inhibitors
10. Metabolic bone disease (including osteoporosis, osteomalacia, osteogenesis imperfect and Paget’s disease)
11. Endocrine disorders (including hyper- or hypo-thyroidism, parathyroid disease, diabetes mellitus and Cushing’s syndrome)
12. Cancer (including cervical, ovarian, uterine, breast, liver and of the gastrointestinal system)
13. Any chronic muscle disease, disorder or injury, and particularly any recent history of low back pain
14. Asthma that is not controlled or other respiratory diseases
15. Self-reported personal or family history of deep vein thrombosis or similar clotting disorders

Study design
Purpose of the study
Educational / counselling / training
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation was not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The experimental and control interventions will be completed in a random order, each separated by 7 days but at the same time of day. Possible intervention orders (e.g. CON, EXP1, EXP2 or EXP2, CON, EXP1…) will be allowed to occur only three times within the trial, which ensures that all possible intervention orders are completed on an equal number of occasions (6 possible test orders allowed 3 times each allows for 18 participants to be tested). Intervention orders will be randomly drawn from a container by a person not otherwise involved in the study.
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
Crossover
Other design features
Phase
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Statistical methods
Differences in the primary and secondary endpoints will be compared between experimental (EXP1 and EXP2) and control (CON) conditions using (multivariate) analyses of variance with repeated measures. Relationships between changes in primary and secondary endpoints will be assessed using correlation/multiple regression analyses and logistic regression. Non-parametric statistical procedures will be used in the event that assumptions associated with parametric procedures are not met. Covariate analyses will be conducted to ascertain the possible influence of factors such as age, height, body mass, etc., where appropriate.

Recruitment
Recruitment status
Recruiting
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)
WA
Recruitment postcode(s) [1] 21620 0
6027 - Joondalup

Funding & Sponsors
Funding source category [1] 298762 0
University
Name [1] 298762 0
Edith Cowan University
Address [1] 298762 0
270 Joondalup Drive, Joondalup, 6027, Western Australia
Country [1] 298762 0
Australia
Primary sponsor type
Commercial sector/Industry
Name
Steel Blue/Footwear Industries Pty Ltd
Address
18 Irvine Dr, Malaga WA 6090
Country
Australia
Secondary sponsor category [1] 297944 0
None
Name [1] 297944 0
Address [1] 297944 0
Country [1] 297944 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 299700 0
the Human Research Ethics Committee (HREC) at Edith Cowan University, Australia
Ethics committee address [1] 299700 0
270 Joondalup Drive, Joondalup, Western Australia, 6027
Ethics committee country [1] 299700 0
Australia
Date submitted for ethics approval [1] 299700 0
Approval date [1] 299700 0
27/09/2017
Ethics approval number [1] 299700 0
18546

Summary
Brief summary
The purpose of the current study is to compare three currently-available work boots for comfort as well as their effects on fatigue, musculoskeletal pain and both physical and cognitive performances.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 81334 0
Prof Anthony Blazevich
Address 81334 0
Edith Cowan University, 270 Joondalup Drive, Joondalup, Western Australia, 6027
Country 81334 0
Australia
Phone 81334 0
+61 8 6304 5472
Fax 81334 0
Email 81334 0
a.blazevich@ecu.edu.au
Contact person for public queries
Name 81335 0
Prof Anthony Blazevich
Address 81335 0
Edith Cowan University, 270 Joondalup Drive, Joondalup, Western Australia, 6027
Country 81335 0
Australia
Phone 81335 0
+61 8 6304 5472
Fax 81335 0
Email 81335 0
a.blazevich@ecu.edu.au
Contact person for scientific queries
Name 81336 0
Prof Anthony Blazevich
Address 81336 0
Edith Cowan University, 270 Joondalup Drive, Joondalup, Western Australia, 6027
Country 81336 0
Australia
Phone 81336 0
+61 8 6304 5472
Fax 81336 0
Email 81336 0
a.blazevich@ecu.edu.au

No information has been provided regarding IPD availability
Summary results
No Results