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Trial registered on ANZCTR


Registration number
ACTRN12609000413224
Ethics application status
Approved
Date submitted
18/05/2009
Date registered
4/06/2009
Date last updated
4/06/2009
Type of registration
Retrospectively registered

Titles & IDs
Public title
Electromyografic analyses of single and multi-joint resistance exercises combinations at diferent intensities.
Scientific title
Electromyografic analyses of single and multi-joint resistance exercises combinations at diferent intensities in healthy male participants.
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Resistance training 4804 0
Condition category
Condition code
Musculoskeletal 237147 237147 0 0
Normal musculoskeletal and cartilage development and function

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Male subjects performed three bouts of exercise in which knee extension and leg press 45 degrees were executed in sequence. In low intensity sequence, 15 unilateral knee extensions were followed by 15 unilateral repetitions of leg press 45 degrees with 30% and 60% of one maximum repetition load (1-RM), respectively. In the high intensity sequence, the same order was used, but the load applied was 60% of one maximum repetition load (1-RM) for both exercises. One single set of 15 repetitions of leg press 45 degrees at 60% of one maximum repetition load (1-RM) was performed as control exercise. The bouts were performed in three different days with 48 to 96 hours between them. The surface electromyographic signal was recorded from the vastus lateralis muscle with a linear electrodes array during the multi-joint exercises.
Intervention code [1] 4579 0
Other interventions
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 237967 0
The electromyographic signals, recorded with linear electrodes array (LISiN - Ot Bioelettronica, Italy) during multi-joint exercises, were analyzed by specific routines developed in the software Matlab 6.5 (Mathworks - Natik, USA). The root mean square (RMS) value was determined for each repetition of leg press 45 degrees and, from these results, a linear regression was calculated. The slopes of regression lines were normalized by their initial values to represent the percentual increase of the root mean square (RMS) value and then compared by the one way Analysis of Variance (ANOVA) for repeated measures performed on a computer using the Statistical Package of Social Science (SPSS 13.0, Lead Technologies, USA). A higher percentual increase in root mean square (RMS) was observed when a single-joint exercise preceded the multi-joint exercise.
Timepoint [1] 237967 0
The bouts were performed in three different days with 48 to 96 hours between them. The electromyographic signal was registered during the execution of leg press 45 degrees of each bout and signal analyses were performed after the end of each test.
Secondary outcome [1] 242070 0
The number of repetitions executed during both single and multi-joint exercises was registered by the researcher. As not all the subjects were capable to execute the 15 repetitions proposed, the number of repetitions were also compared by the one way Analysis of Variance (ANOVA) for repeated measures calculated with the Statistical Package of Social Science (SPSS 13.0, Lead Technologies, USA).
Timepoint [1] 242070 0
The researchers spotted all the experimental procedure and registered the number of repetitions executed by the subjects during both single and multi-joint exercises of each bout.

Eligibility
Key inclusion criteria
Training experience of one year in resistance training practicing resistance exercises at least three times a week.
Minimum age
18 Years
Maximum age
27 Years
Gender
Males
Can healthy volunteers participate?
Yes
Key exclusion criteria
Cronic or acute injuries in lower limbs or negative answers in Physical Activity Readiness Questionnaire - PAR-Q.

Study design
Purpose of the study
Educational / counselling / training
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
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Phase
Not Applicable
Type of endpoint(s)
Safety
Statistical methods / analysis

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 outside Australia
Country [1] 1782 0
Brazil
State/province [1] 1782 0
Brasilia

Funding & Sponsors
Funding source category [1] 4971 0
Self funded/Unfunded
Name [1] 4971 0
Valdinar de Araujo Rocha Junior
Address [1] 4971 0
QND 59 casa 34
Taguatinga - Distrito Federal
postcode: 72.120-590
Country [1] 4971 0
Brazil
Funding source category [2] 5073 0
Self funded/Unfunded
Name [2] 5073 0
Address [2] 5073 0
Country [2] 5073 0
Primary sponsor type
University
Name
Universidade de Brasilia
Address
Campus Universitario Darcy Ribeiro
Brasilia-DF, 70.919-970
Country
Brazil
Secondary sponsor category [1] 4497 0
None
Name [1] 4497 0
Address [1] 4497 0
Country [1] 4497 0
Secondary sponsor category [2] 4581 0
None
Name [2] 4581 0
Address [2] 4581 0
Country [2] 4581 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 7076 0
Comite de Etica em Pesquisa da Faculdade de Ciencias da Saude - FS/UnB
Ethics committee address [1] 7076 0
Campus Universitario Darcy Ribeiro
Faculdade de Ciencias da Saude
70910-900
Ethics committee country [1] 7076 0
Brazil
Date submitted for ethics approval [1] 7076 0
Approval date [1] 7076 0
21/12/2007
Ethics approval number [1] 7076 0
131/2007

Summary
Brief summary
Purpose: To verify if the execution of a low intensity single-joint exercise for knee extensors is an efficient stimulus to increase vastus lateralis motor units recruited during a subsequent multi-joint exercise. Methods: Nine healthy male subjects (23.33 +/- 3.46 years old) performed three bouts of exercise in which knee extension and leg press 45 degrees were executed in sequence. In low intensity sequence (R30) 15 unilateral knee extensions were followed by 15 repetitions of leg press 45 degrees with 30% and 60% of one maximum repetition load (1-RM), respectively. In the high intensity sequence (R60), the same order was used, but the load applied was 60% of 1-RM for both exercises. One single set of 15 repetitions of leg press 45 degrees at 60% of 1-RM was performed as control exercise (C). The surface electromyographic signal was recorded from the vastus lateralis muscle with a linear electrodes array. The root mean square (RMS) value was determined for each repetition of leg press 45 degrees and a linear regression was calculated with these results. The slopes of regression line were normalized by their initial values and then compared by one way Analysis of Variance (ANOVA) for repeated measures. Results: The slopes observed in C were significant lower than the slopes calculated in R30 and R60 (p < 0.05). Conclusion: The results suggest a higher recruitment of motor units when a single-joint exercise preceded the multi-joint exercise.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 29616 0
Address 29616 0
Country 29616 0
Phone 29616 0
Fax 29616 0
Email 29616 0
Contact person for public queries
Name 12863 0
Valdinar de Araujo Rocha Junior
Address 12863 0
QND 59 casa 34
Taguatinga - DF
72.120-590
Country 12863 0
Brazil
Phone 12863 0
+55 61-3254-1065
Fax 12863 0
+55 61-2024-8875
Email 12863 0
valdinar.varj@dpf.gov.br
Contact person for scientific queries
Name 3791 0
Valdinar de Araujo Rocha Junior
Address 3791 0
QND 59 casa 34
Taguatinga - DF
72.120-590
Country 3791 0
Brazil
Phone 3791 0
+55 61-3254-1065
Fax 3791 0
+55 61-2024-8875
Email 3791 0
valdinar.varj@dpf.gov.br

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