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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
Prospectively registered

Titles & IDs
Public title
The effect of load and exercise speed on activation pattern of middle trapezius and posterior deltoid muscles in prone fly position.
Scientific title
The Effect of Load and Repetition Velocity on Recruitment Timing of Middle Trapezius and Posterior Deltoid Muscles in Prone Shoulder Horizontal Abduction with External Rotation.
Secondary ID [1] 298197 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Shoulder movement dysfunction 312786 0
Condition category
Condition code
Musculoskeletal 311281 311281 0 0
Other muscular and skeletal disorders

Study type
Description of intervention(s) / exposure
After Maximum Voluntary Isometric Contraction (MVIC) Testing, there should be a five-minute rest for each subject before proceeding. In the starting position, subjects lay prone on the treatment table with neutral shoulders resting in 90° forward flexion (to confirm with goniometer measurements). Prone Horizontal Abduction in External Rotation (PHAER) is performed by extending elbows and horizontally abducting shoulders to a horizontal position, adding external rotation of the shoulder towards the end of the movement.
Subjects will undergo a dynamic warm-up of shoulder movements in all directions within their available range. Skin impedance will be reduced by shaving any hair on the skin and thorough cleaning with an alcohol swab. Proper electrode placement will be confirmed by monitoring EMG signals during specific muscle testing.
First, subjects will complete 3 trials of 5 PHAER exercises (progressive load from 0.5 to 2 kg), with a 2-minute rest between exercises. Repetition velocity will be kept consistent at two seconds concentric to two seconds eccentric using a metronome.
Second, subjects will complete 3 trials of 5 PHAER exercise (progressive velocity from 4 to 0.5 seconds), with a 2-minute rest between exercises.
The study will be administered by the Principal Investigator and Co-Investigators approved by the ethics committee.
The trial is conducted through direct participant engagement.
Each participant is expected to spend 2 hours in the trial and will be remunerated with cash vouchers.
The trial is conducted in the Singapore Institute of Technology and opened to the public. Each participant is involved in 1 session.
Intervention code [1] 314433 0
Comparator / control treatment
Control group

Primary outcome [1] 320026 0
Maximum Voluntary Isometric Contraction of middle trapezius muscle using EMG measurement.
Timepoint [1] 320026 0
Secondary outcome [1] 370280 0
Maximum Voluntary Isometric Contraction of posterior deltoid muscle using EMG measurement.
Timepoint [1] 370280 0

Key inclusion criteria
- 21 to 30 years of age
- Able to perform PHAER in a pain-free range of motion
- Males with a bodyweight of 50kg to 85kg
- Females with a bodyweight of 50kg to 75kg
Minimum age
21 Years
Maximum age
30 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
- History of shoulder dislocation or surgery
- Current symptoms related to the cervical spine
- Documented structural injuries to the shoulder complex
- Participation in competitive overhead sports or high-level upper extremity strength training on a regular basis
- On-going orthopaedic follow-up appointment
- Body weight that does not fall within the inclusion criteria

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
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
First, mean recruitment timings (in milliseconds) and standard deviations will be calculated for each muscle in each exercise. The activation timing of MT relative to PD will be determined by subtracting the mean recruitment time of PD from that of MT. Negative values reflect MT muscle recruitment before PD while positive values reflect MT muscle recruitment after PD. Data will be assessed for normality using the Shapiro-Wilk test on SPSS v25. To investigate the relationship between MT to PD recruitment timing against (1) load and (2) repetition velocity variation, regression modelling of analysis of variance (ANOVA) will be used. Timing differences between the dominant and non-dominant arm will be analysed through a paired t-test.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 21462 0
State/province [1] 21462 0

Funding & Sponsors
Funding source category [1] 302739 0
Name [1] 302739 0
Singapore Institute of Technology
Address [1] 302739 0
10 Dover Dr Singapore 138683
Country [1] 302739 0
Primary sponsor type
Singapore Institute of Technology
10 Dover Dr Singapore 138683
Secondary sponsor category [1] 302671 0
Commercial sector/Industry
Name [1] 302671 0
Clinical Pilates Family Physiotherapy
Address [1] 302671 0
2 Venture Dr #02-04 Singapore 608526
Country [1] 302671 0

Ethics approval
Ethics application status
Ethics committee name [1] 303341 0
SIT Institutional Review Board
Ethics committee address [1] 303341 0
10 Dover Dr Singapore 138683
Ethics committee country [1] 303341 0
Date submitted for ethics approval [1] 303341 0
Approval date [1] 303341 0
Ethics approval number [1] 303341 0

Brief summary
Studies have shown that individuals experiencing shoulder pain display delayed recruitment of the trapezius muscle in relation to the deltoid muscle during arm movements. Prone shoulder horizontal abduction with external rotation is a commonly prescribed shoulder rehabilitation exercise that may be beneficial in the treatment of timing disorders of the trapezius muscle. Our research team would like to better understand how variations in dumbbell weight and repetition speed impact activity of selected back and shoulder muscles in healthy adults during this exercise.
Our goal is to contribute to developing safer and more effective exercises for individuals suffering from various shoulder injuries.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 93338 0
Mr Kwok Boon Chong
Address 93338 0
Clinical Pilates Family Physiotherapy
2 Venture Dr #02-04 Singapore 608526
Country 93338 0
Phone 93338 0
Fax 93338 0
Email 93338 0
Contact person for public queries
Name 93339 0
Mr Kwok Boon Chong
Address 93339 0
Clinical Pilates Family Physiotherapy
2 Venture Dr #02-04 Singapore 608526
Country 93339 0
Phone 93339 0
Fax 93339 0
Email 93339 0
Contact person for scientific queries
Name 93340 0
Mr Kwok Boon Chong
Address 93340 0
Clinical Pilates Family Physiotherapy
2 Venture Dr #02-04 Singapore 608526
Country 93340 0
Phone 93340 0
Fax 93340 0
Email 93340 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
This is to protect the privacy and confidentiality of each participant.
What supporting documents are/will be available?
Ethical approval
How or where can supporting documents be obtained?
Type [1] 2039 0
Ethical approval
Citation [1] 2039 0
Link [1] 2039 0
Email [1] 2039 0
Other [1] 2039 0
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