Ergonomics

1. Ergonomics Murray State University

2. Good Working Positions • To understand the best way to set up a computer workstation, it is helpful to understand the concept of neutral body positioning. • This is a comfortable working posture in which your joints are naturally aligned. • Working with the body in a neutral position reduces stress and strain on the body.

3. Neutral Body Positions • Hands, wrists, forearms are straight, in-line and roughly parallel to the floor • Head is level, or bent slightly forward, forward facing and balanced • Shoulders are relaxed and upper arms hang normally at your side • Elbows stay in close to the body and are bent 90-120 degrees

4. Neutral Body Positions • Feet are fully supported by floor or footrest • Back is fully supported when sitting vertical or leaning back slightly • Thighs and hips are supported by a well-padded seat and are parallel to the floor • Knees are same height as the hips with feet slightly forward

5. Prolonged Periods of Sitting • You should change your work position frequently throughout the day: • Make small adjustments to your chair or backrest • Stretch your fingers, hands, arms, and torso • Stand up and walk around for a few minutes periodically

6. 4 Reference Postures • These four reference postures are examples of body posture changes that keep the neutral positioning of the body: • Upright Sitting • Standing • Declined Sitting • Reclined Sitting

7. Upright Sitting • The user’s torso and neck are approximately vertical and in-line, the thighs are horizontal, and the lower legs are vertical.

8. The user’s legs, torso, neck, and head are in-line and vertical. The user may also elevate one foot on a rest. Standing

9. Declined Sitting • The user’s thighs are inclined with the buttocks higher than the knee and angle between the thighs and torso is greater than 90 degrees.

10. Reclined Sitting • The user’s head and neck are straight and recline between 105 and 120 degrees from the thighs.

11. Computer Workstations • There are simple, inexpensive ways to create a safe and comfortable computer workstation. • Monitor • Keyboard • Pointer/Mouse • Wrist/Palm Support • Document Holder • Desk and Chair • Telephone

12. Monitor • Put monitor directly in front of you and at least 20 inches away. • Place monitor so top line of screen is at or below eye level. • Place monitor perpendicular to window to reduce glare.

13. Keyboard • Put the keyboard directly in front of you. • Your shoulders should be relaxed and elbows close to your body. • Your wrists should be straight and in-line with forearms.

14. Keyboard Positions Keyboard is too far away Keyboard is too close

15. Pointer/Mouse • Keep the mouse close to the keyboard. • Alternate hand with which you operate the mouse. • Use keyboard shortcuts to reduce extended use.

16. Wrist/Palm Supports • Use a wrist rest to maintain straight wrist postures and to minimize contact stress during typing and mousing tasks.

17. Document Holder • Documents should be at the same height and distance as the monitor.

18. Desk • Desk surface should allow you to place the monitor directly in front of you, at least 20 inches away. • Avoid storing items, such as CPU under the desk. • Desk should be able to accommodate a variety of work postures and tasks.

19. Desk • The location of frequently used devices (keyboard, mouse, phone) should remain within the repetitive access zone.

20. Chair • The backrest should conform to the natural curvature of the spine, and provide lumbar support. • The seat should be comfortable and allow your feet to rest flat on the floor or footrest. • Armrests, if provided, should be soft, allow your shoulders to relax and elbows to stay close to your body.

21. Telephone • Use a speaker phone or head set for long conversations. • Keep it close enough to avoid repeated reaching.

22. Work Process and Recognition • Even when the design of the workstation is correct and environmental factors are at their best, users can face risks from task organization which can intensify the impact of other risk facts, such as repetition. • Take several short rest breaks. • Alternate tasks, mixing non-computer related tasks into the workday.

23. Workstation Environment • Arrange your workstation to minimize glare from overhead lights, desk lamps, and windows. • Maintain adequate air circulation. • Avoid sitting directly under air conditioning vents for better comfort.

24. What’s Wrong Here? Workspace is too cluttered, misalignment of keyboard and monitor, keyboard and monitor are too high and too far away

25. What’s Wrong Here? Monitor and keyboard not aligned, monitor is too close, keyboard is too high, shelf casts shadow on work area

26. What’s Wrong Here? Extended reach for mouse, phone cord knocks off mouse, using phone and keyboard requires cradling of phone

27. What’s Wrong Here? Misalignment of chair, monitor and keyboard, monitor is too far away, phone has to cradled while also using keyboard

28. What’s Wrong Here? Misalignment of keyboard and monitor, desk is too low, chair does not provide adequate back support

29. Good Workstation Setup Good alignment of monitor, keyboard and mouse, good distance and height

30. Summary • Consider your workstation and see if you can identify areas of improvement in- • Posture • Component placement • Work environment • Create your own “custom-fit” computer workstation.