A short lecture on ergonomic principles and computer operator ergonomics and recent advances.

1. OFFICE ERGONOMICS
Dr. Shrikant Sant
Asst. Professor
Community Physiotherapy Department
Dr. D. Y. Patil College of Physiotherapy, Pune.

2. OFFICE ERGONOMICS
 UNC - Charlotte
 Safety and
Environmental
Health Department
 King Building – 1st

3. DEFINITION
 ERGONOMICS is a way of working
smarter--not harder by designing tools,
equipment, work stations and tasks that
allow a job to fit the worker and NOT by
fitting the worker to the job:
 Layout / type of controls & displays
 Lighting & Temperature
 Process (Heights, reaches, weights)

4. MSD INJURY DATA
 600,000 MSDs require time off
from work.
 Women suffer more ergonomic
injuries due to:
 jobs requiring more heavy lifting,
repetitive movement while completing
tasks and awkward postures and as a
result account for:
 70% of Carpal Tunnel
 62% of Tendonitis

5. CAR COST IS (PARTIALLY)--A PAIN IN
THE BACK !!
 According to Dr. E.W. Simmons,
president of the American Back
Society, medical costs related
to back injuries can add up to
$1,800 to the price of every car
made in Detroit!

6. CTD INJURY FACTORS
 CTD Injuries cause Lesions
to tendons of the neck,
back, shoulders, arms,
wrists or hands
 Primary causes:
 Repetitive movements
over long periods of time
 Awkward postures
 Use of excessive forces

7. CTD RISK CONTROL: POSTURE
 NEUTRAL & COMFORTABLE:
 Wrists straight
 Shoulders relaxed with
elbows close to body
 head / shoulders & back in
vertical alignment
 Feet flat on floor
 Frequent breaks when
bent postures can’t be
avoided

8. ERGONOMIC ALIGNMENT
 Proper tool alignment illustrated – note
wrist and elbow positioning

9. CARPAL TUNNEL SYNDROME
 Up to 15% occurrence rate in certain industries.
 A natural occurrence with repetitive motion of
hands & wrists -- especially with high force levels
and awkward wrist positioning.
 Proper keyboard positioning and good wrist support
can help most PC users avoid problems
 GOOD NEWS: rates have dropped about 30%
since 1990 -- which most attribute to strong
workplace ergonomics programs

10. CTD RISK CONTROL:
REPETITION
 Use automatic tools for repetitive tasks
(screw and bolt tightening)
 Eliminate unnecessary tasks /
movements by redesigning maintenance
procedures and workstations
 Take short, frequent breaks
 Alternate tasks and processes to use
different muscle groups

11. ERGONOMICS SUMMARY
 Good ergonomic design of tools, processes
and furniture can markedly improve
personnel comfort, health, morale, and
productivity.
 Individual effort as part of a departmental
workshop team is the greatest means of
identifying / improving workplace
ergonomic issues.
 It’s critical to seek prompt medical aid for
symptoms of ergonomic stress / CTDs.

12. Computer Ergonomics
 Routine PC user is defined as a person spending
20 hours or more per week working at a
computer.
 Studies of PC users have not shown a risk of eye
damage...although fatigue is quite possible
during extended usage.
 NIOSH studies have not indicated a radiation
hazard nor pregnancy risk from PC usage.
 Workers using bi/tri-focal glasses that use a PC
may need special purpose glasses for computer
work that keep eyes/head on level plane.

13. ERGONOMIC KEYBOARDS
 Three types: Fixed split, Adjustable split &
“Sculptured”
 Awkward wrist postures minimized with 15 to
25 horizontal degree key split AND 8 to 66
degree vertical incline.
 Key Layout Design Changes Have:
 increased comfort (81% of users)
 improved postures
 reduced muscle activity
 lowered carpal tunnel pressure in lab
settings
 Obtained primarily to alleviate an injury

14. WRIST RESTS
 No medical evidence that they reduce RSI injuries. They
work for some, but not for others
 Usage Guidelines:
 Buy rest that is even with top of keyboard
 Material should be “medium-soft” (foam--gel mix) so
foam doesn’t break down. AVOID hard plastic types
 DON’T leave wrists on rest...which compresses carpal
tunnel. Palm rest instead.
 Changing typing habits more critical than wrist support
 MOST APPROPRIATELY USED TO REST HANDS DURING
PAUSE IN TYPING
 LEARN TO TYPE CORRECTLY WITH “FLOATING WRISTS”
FIRST!!!

15. Ergonomic chairs
 Adjustable back height
 Adjustable arm rests
 Adjustable Seat Pan Tilt
and Height to
accommodate user body
type
 Note: Chair on left is NOT
ergonomically designed –
it is equipped with fixed
arm rests and non-
adjustable back and seat
pan height

16. Alternative Pointing Devices
 Track-balls
 “Scrolling” Mouse

17. Other Ergonomic PC
Accessories
 Height-adjustable articulating keyboard tray – controls
height and tilt adjustments, allows proper keyboard
positioning for many different body types.
 3M model AKT 100 shown above is a good example of
a well made keyboard tray.

18. Ergonomically Incorrect PC Station Design

19. Ergonomically Correct PC Station Design

20. Model Computer Workstation
 Keyboard trays WITH wrist
support.
 Split "Natural" keyboards to
facilitate neutral wrist angle
 Fully adjustable ergonomic
chair
 Document holder to minimize
head / eye & neck movements
 Corner desk units to position
monitor directly in front of
employee
 Foot rest where requested.
 Re-organization of working
materials within employee arm
reach.
 Alternative pointing devices

21. Questions ??... Contact S & EH
 Workplace ergonomic assessments will
be provided by Safety and
Environmental Health Dept upon
request.
 S, & EH phone extension – 4279
 HAVE A SAFE AND HEALTHY DAY