the ergonomic implications of gesturing examining single and mixed use with appropriate placement...
TRANSCRIPT
The Ergonomic Implications of Gesturing
Examining Single and Mixed Use with Appropriate Placement
Lindsey Muse B.A., S. Camille Peres Ph.D., Adrian GarciaUniversity of Houston-Clear Lake
The Problem: Research not keeping up with Technology•Number of products with touch screen
capabilities is increasing•Limited research available concerning the
ergonomic impacts of gesturing
▫Existing research is almost completely based on subjective measurements
•Designers and developers need objective measures accompanied with subjective measures to understand the impact of gesturing on the body to help avoid injury
Areas of Interest for Ergonomics(Independent Variables)
•Types of touch screen devices▫Handheld▫Pad▫Laptop▫Desktop
•Input Styles:▫Single Use: Touch only▫Mixed Use: Touch and keyboard or mouse where
it applies• Possible placement for each product
▫Desk, Lap, Hand while sitting, Hand while standing
Conditions
Participants•100 participants from within and outside of the University of Houston-Clear Lake▫Outside the university
$1oo each for participation▫Within the university
One hour of participation credit for every hour in the study
•Participants will be selected so they have some experience with at least one of the gesture input devices
Objective Measures
•Surface EMG (SEMG)▫12 electrodes placed on the upper body to
measure muscle activity during testing Bilateral - flexor, extensor, trapezius, deltoid,
thenar and hypothenar Mean and Standard deviation of RMS of SEMG
Subjective Measures
•Modified Body Discomfort Diagram▫17 body parts and muscle groups for
participants to rate (primarily looking at the upper body)
•Open-ended questions▫Participants’ computer usage▫Their comfort or discomfort after each
session
Goals•Obtain objective and subjective ratings from
participants for the 4 touch screen devices ▫Gather data with different input styles (single
and mixed use) where applicable▫Gather data in the different postures that apply
to each device•Better understand the risks involved for these
4 products •Provide valuable information to minimize risks
in current and future technologies
Appendix:Timeline
Appendix:Budget
Appendix:Data Analysis
•Primarily exploratory and descriptive analyses:▫ANOVA’s calculated for each dependent
measure on each device (and by environment where appropriate) subjective: BDD objective: S-EMG
▫Summary of comments on open ended questions
Analyses-Subjective
• BDD: difference in ratings by • device, posture, muscle, session
• free choice• input device, posture
• free response• most uncomfortable task, how uncomfortable
were they with the posture• did counterbalance seem to matter with any of
these?
Analyses-Objective• SEMG:
• Mean EMG: by device, task, muscle, posture• SD EMG: by device, task, muscle, posture
• Motion Capture• 3 angles: shoulder abduction (?), elbow extension,
torso lean (?)• per device and posture (two prescribed postures):
• Typical worst posture• how long until participants assume that posture• how long they maintain the posture
• per device - free choice: • Typical worst posture• how long until participants assume that posture• how long they maintain the posture