Ergonomics Of Computer Usage

Ergonomics of Computer Usage Dr Sanjoy Sanyal MBBS, MS, MSc (UK), ADPHA, ADHRD Seychelles Presented in Seychelles medical college in September 2007

A few simple measures can avoid a lot of pain in the neck (pun unintended!)

Posturing body parts
Computer directly in front
Forearms horizontal
Wrists in neutral, comfortable position
Upper arms hang naturally at sides
Breaks during sessions

Upper limbs
Wrists in neutral position, neither bent up, down nor sideways.
Do not lean wrists on wrist-straps while typing.
Shoulders / arms relaxed and hanging naturally.
Elbow / forearm rest comfortably on work surface, parallel to floor;
Elbow at 90-degree angle.

Lower limbs
Back of knees extending no more than 3-4 finger lengths from end of chair.
Thighs parallel to floor, comfortably supported on seat of chair
Leg-torso angle = 90-100 degrees
Feet in front of seat and resting flat on floor.
If feet are not reaching floor, adjust height of chair, or put a footrest under feet.

Wrong workstation posture

Correct workstation posture

Spine and back
Back in full contact with backrest
Lumbar curve of chair fitting lumbar spine
Avoid improper body alignment
Neck straight or slightly forward.
Avoid looking up and improper neck posture

Chair
Adjustable backrest - tilts easily, yet provides solid back support
Curved lumbar support
Able to be raised / lowered, swiveled / locked at different angles
Average adult : Seat 1½ feet (45 cm) above ground, placed 1½ feet (45 cm) from table; table 2 -2 ½ feet (60-75 cm) high.

Eyes
Avoid locking eyes into fixed-screen stare .
‘ Rule of 30 ’: Every 30 minutes look towards an object approximately 30 feet away, for 30 seconds.
Keep eyes level with upper margin of monitor
Should not be necessary to swivel eyes downwards > 40 degrees from horizontal when looking from top to bottom of screen.

Workstation setup

Desktop screen
Anti-glare screen.
In front of a window, its back facing the window.
Screens < 17 inches (43 cm) should be one-arm + 3 inches away from fingertips.
Larger screens 7-8 inches away from fingertips.
Or , 1 ½ to 2 feet (45 to 60 cm) from eyes.
Screen directly in front of user’s eyes, not angled in vertical or horizontal axes.

Laptop screen
Adjust viewing angle for:
Best display
Least eye strain
Least muscle fatigue
Optimum brightness

Desktop peripherals
Top margin of monitor at eye-level.
Mouse to right or left of keyboard, at same height.
Keyboard located at elbow height
‘ B'-key lined up with the navel
Keyboard legs should be knocked down, so that it lies flat on table
Wrist-rests may be used to reduce strain on wrists.

Room lighting
Work area adequately lit / ventilated.
Windows/lights should not create glare / reflection on display
Indirect light to avoid bright spots on display
Overhead lighting is best, or
Fluorescent light with a grid or shield covering the fixture

“ Keep head on your shoulders, Watch your hand, Look straight, Keep an eye on your back.”

References
Dr Venkata Ramana Rao , RSI specialist, myotherapist and ergonomist; RSI Healthcare.
Rich Epstein , Director of the Moore Center for Rehabilitation, Stamford and a founder of the Moore Center Ergonomics and Injury Prevention Company

THAN-Q

Ergonomics Of Computer Usage

by Sanjoy Sanyal

Accessibility

Categories

Upload Details

Usage Rights

1 Embed 4

Statistics

Ergonomics Of Computer Usage Presentation Transcript