SAMPLE INFORMATION LETTER: Biomechanics (2) Research
(Department/School logo, name, address)
______________________________________________________________________
Study Title:
(insert title)
Student Investigator:
(insert name, department, email)
Faculty Supervisor:
(insert name, department, email, phone)
Purpose of the Study
Maximum voluntary electrical activation (MVE) is used as a reference level of activation to
normalize electromyography (EMG) data, which facilitates comparison of muscular activity
across persons. Therefore, the magnitude of an MVE is critical to accurately compare muscle
activations that occur in various tasks and movements. Conducting an MVE involves a
participant maximally contracting a target muscle for 5 seconds. A particular concern with using
MVEs to normalize EMG data is that they are highly variable and they may not be true
representations of maximum activation. Several factors, such as training and feedback affect
the accuracy of an MVE but it is unclear if unilateral or bilateral contractions are preferred for
eliciting greater activation in the shoulder muscles. Unilateral contractions refer to contractions
of muscles on only one side of the body while bilateral contractions are simultaneous
contractions of the same muscles on both sides of the body. Current theories in the literature
propose that there may be greater neural drive during bilateral contractions than unilateral
contractions. If this is the case, magnitude of MVE values can be improved if bilateral
contractions are performed. Therefore, the goal of this study is to determine whether greater
muscle activity results by performing bilateral MVEs than unilateral MVEs. A secondary purpose
is to evaluate the repeatability of MVE values with both techniques. This will lead to improved
MVE estimates and therefore enhance normalized estimates of loads on shoulder muscles
when performing tasks at a sub-maximal level. The results of the study will be used to improve
our current protocol for estimating relative contributions of the shoulder muscles during different
simulated occupational tasks.
Procedures Involved in this Study and Time Commitment
Prior to coming to the lab, you will be asked to wear a loose fitting t-shirt. Upon arrival, the skin
overlying each of the target muscles will be shaved and cleansed before the self-adhesive
disposable EMG electrodes are attached. EMG activity will be recorded as you perform 4
standardized isometric tests. EMG activity will be recorded for the back muscles (upper
trapezius and the infraspinatus), shoulder muscles (anterior deltoid, middle deltoid and posterior
deltoid) and chest muscles (pectoralis major).The testing session will take approximately 1.5 - 2
hours.
Exclusion Criteria:
You will be excluded from participation if you answer yes to “Have you had any shoulder, neck,
elbow or wrist injury or pain in the past 6 months?”
Also, you will be asked if you have an allergy or skin sensitivity to rubbing alcohol, since rubbing
alcohol is used in placement of electrodes. If you have had injury or pain in the specified areas
or are allergic, to rubbing alcohol you will be informed that you cannot participate in the study.
Instrumentation:
You will be reminded to ask any questions you may have before or during the session.
Disposable EMG electrodes are attached to the skin overlying muscles of interest. The hair in
the placement area is shaved to enhance the signal and to make the removal of the electrode
easier. A new disposable razor is used for each participant. A female RA/graduate student
shaves female participants and a male RA/graduate student shaves male participants. If you
have any concerns about shaving a placement area, then that area will not be shaved and data
will not be collected for the corresponding channel. If you do not wish to have an area shaved,
please inform the investigator and that muscle will be omitted.
After the skin areas are shaved, electrode placement areas are cleansed with rubbing alcohol to
remove dead skin and improve the quality of the EMG signal. One self-adhesive dual-electrode
is attached to the skin overlying each of the muscles for which MVEs will be conducted. A total
of 12 dual-electrodes will be adhered to the skin. On each side of the body, two pairs of
electrodes will be attached to the skin overlying the back muscles, 3 pairs on the shoulder
muscles and 1 pair on the chest muscles. Therefore, six pairs of electrodes will be attached on
the left side and six pairs of electrodes on the right side of the body.
All instrumentation that will be used in this study is CSA approved.
Experimental Protocol:
Following the electrode placement, you will perform a total of 24 exertions with a minimum of 2
minutes of rest between all exertions. The order of the MVEs will be randomized. You will be
asked to perform 3 repeats of each unilateral and each bilateral MVE version of the described
MVE tests (also see figure 1 below):
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Empty can test: You will grab a stationary handle with the thumb pointing towards the
ground and apply a maximum upward force with your elbow extended and directly
perpendicular to your torso. The stationary handle will act as a resistor to the force.
External rotation 0o test: You will grab a stationary handle with the upper arm adjacent to
the torso and the elbow flexed at 90o with the forearm in neutral position (palm of the
hand faces the midline of the body), You will attempt to “pull” outwards with maximum
force in the horizontal plane by rotating the shoulder. The stationary handle will act as a
resistor to the force.
Flexion 125o test: Sitting in an upright position your shoulder is flexed to 125o where you
will grip a handle and attempt to flex you arm further while the investigator will apply
manual resistance above the base of your scapula.
Palm press: You will have both shoulders flexed at 90o and elbows flexed at 20o. Heels
of the hands will come together and you will horizontally resist one hand against the
other. For the unilateral version of this test, you will apply a maximum force in the
horizontal direction with the palm facing towards the midline of the body to a stationary
object. The stationary object will act as a resistor to the force.
All MVEs will be held for 5 seconds and unilateral MVEs will be performed by the muscles on
your dominant side. When performing the exertions, you will increase the contraction up to a
maximum contraction over the first second, hold the maximum contraction for 3 seconds and
decrease contraction over the last second. To ensure maximum activation, instantaneous visual
force feedback will be provided by displaying the instantaneous force that you are producing on
a screen, and a reference line illustrating the highest force you will have achieved in the
experiment. Verbal encouragement will also be provided as you perform the exertions.
You will be video recorded and/or photographed during the session. Typically, this will be of
your whole body. These images are used for analysis of the data by trained observers and/or
computer models.
Upon completion of the 24 exertions, electrodes will be removed from the skin. The areas on
which electrodes were attached will be cleansed of all residual gel and adhesive from the
electrode.
Figure 1 – Experimental protocol flow chart
Potential Risks and Associated Safeguards
Removal of electrodes may leave a red mark on your skin. Some participants may experience
mild irritation or redness due to the attachment of instrumentation, similar to mild irritation that
may occur when you remove a bandage. The occurrence of skin irritation is rare amongst
participants and it typically fades within 1-3 days.
There is no risk of electrical shock. All portable parts of the electrical recording systems are
battery operated and isolate you from the main power lines.
Upon completion of the study, you may experience mild muscle soreness or stiffness due to the
repetitive maximal exertions. This is similar to what you may experience after a weight training
work-out at the gym. The stiffness and soreness typically fades within 3 days. A minimum of 2
minutes of rest is mandatory in this study, between each exertion. Two minutes is the
recommended amount of rest but you are permitted to rest for longer period of time if you
require. This helps minimize the stiffness you may develop after the study. You are instructed to
discontinue the study at any time especially if you experience undue fatigue or muscle
soreness.
All equipment used in this study is CSA approved.
Changing Your Mind about Participation
You may withdraw from the study at any time without penalty. To do so, indicate this to the
investigators by saying, “I no longer wish to participate in this study”.
Potential Benefits of Participation
You will have the opportunity to further your knowledge and understanding of experimental
procedures and theories in human movement research. You will learn how muscle activity is
measured using EMG, as well as the importance of using MVEs to normalize EMG data and to
determine the amount of relative muscle activity produced in a task.
Confidentiality and Security of Data
An alphanumeric or numerical code will be associated with your name; no personal identifiers
will be included. The alphanumeric/numerical code will be used with the video recording. Your
name will not be associated with the recording. All data will be stored indefinitely on computer
hard drives (password protected) and/or digital storage media (locked in the investigator’s filing
cabinet, in BMH 1404). A separate consent will be requested in order to use photographs for
teaching, for scientific presentations, or in publications of this work.
Concerns about Participation
We would like to assure you that this study has been reviewed by, and received ethics
clearance through a University of Waterloo Research Ethics Committee. However, the final
decision about participation is yours. In the event you have any comments or concerns
resulting from your participation in this study, please contact Dr. Maureen Nummelin, the
Director, Office of Research Ethics, at 1-519-888-4567, Ext. 36005 or
maureen.nummelin@uwaterloo.ca.
Questions about the Study
If you have any further questions or want any other information about this study, please feel free
to contact (insert student investigator’s name) or Prof. (insert faculty supervisor’s name)
(contact information provided below).
Sincerely Yours,
Insert investigators names and contact information)
CONSENT OF PARTICIPANT
I have read the information presented in the information letter about a study being conducted by
(insert name of Student Investigator) and Prof. (insert name of Faculty Supervisor) of the
Department of Kinesiology at the University of Waterloo. I have had the opportunity to ask any
questions related to this study, to receive satisfactory answers to my questions, and any
additional details I wanted. I am aware that I may withdraw from the study without penalty at
any time by advising the researchers of this decision.
This project has been reviewed by, and received ethics clearance through a University of
Waterloo Research Ethics Committee. I was informed that if I have any comments or concerns
resulting from my participation in this study, I may the Director, Office of Research Ethics at
(519) 888-4567 ext. 36005.
With full knowledge of all foregoing, I agree, of my own free will, to participate in this study.
Participant’s Name (Please Print): ______________________________________________
Participant’s Signature: _______________________________________________________
Dated at Waterloo, ON: _______________________________________________________
Witnessed: _________________________________________________________________
CONSENT TO USE PHOTOGRAPHS IN TEACHING, PRESENTATIONS,
and/or PUBLICATIONS
Project title:
(insert title)
Student Investigator: (insert name)
Faculty Supervisor:
(insert name)
Sometimes a certain photograph clearly demonstrates a particular feature or detail that would
be helpful in teaching or when presenting the study results at a scientific conference or in a
publication.
I agree to allow photographs in which I appear to be used in teaching, scientific presentations
and/or publications with the understanding that I will not be identified by name. I am aware that
I may withdraw this consent at any time without penalty, and the photograph will be
confidentially deleted.
I was informed that if I have any comments or concerns resulting from my participation in this
study, I may contact the Director, Office of Research Ethics) at (519) 888-4567 ext. 36005 or by
email, maureen.nummelin@uwaterloo.ca.
Participant’s Name (Please Print):
________________________________________________
Participant’s Signature:
_________________________________________________________
Dated at Waterloo, ON:
_________________________________________________________
Witnessed:
___________________________________________________________________