Ergonomic principles in rehabilitation

2.  Introduction
 The necessity of applying Ergonomics Principles
 Ergonomics Risk factors and problems associated
with them
 Types of Ergonomics Injury
 How to avoid Ergonomics Injury ?
 Key elements of successful Ergonomics Program
in a workplace
 Pillars of Ergonomics Design
 Summary
 References

3.  Ergonomics derived from two Greek words
 Ergon means “WORK “
 Nomos means “ LAW “
 Ergonomics focuses on the study of work
performance with an emphasis on worker
safety and productivity.

4.  According to OSHA: “Designing the job to
fit the workers, instead of forcing the
worker to fit the job “
 According to Tayyari & Smith: defined as
“Branch of science that focuses on
obtaining optimal relationships between
workers and their work environment.”

5.  Ergonomics emerged as a scientific discipline in
the 1940s as a consequence of the growing
realisation that, as technical equipment became
increasingly complex, not all of the expected
benefits would be delivered if people were
unable to understand and use the equipment to
its full potential.(According to the Institute of Ergonomics and Human factor )

6.  A process aimed at enabling persons with
disabilities to reach and maintain their
optimal physical, sensory, intellectual,
psychiatric and/or social functioning levels,
thus providing them with the tools to change
their lives towards a higher level of
independence.

7.  Workstation Design—(desks, chairs, space, layout)
 Work Postures (sitting, standing, reaching, lifting)
 Work Organization (Pace, Breaks,Variety)
 Tools, Equipment, and Furniture Design---(body size, height,
gender, promoting neutral postures, reduced vibration, exposure to
acceptable lighting, noise, temperature)
 Manual Materials Handling—(lifting, lowering, pulling, pushing,
carrying and holding materials)
 Work Environment—(ventilation, noise, temperature & humidity,
lighting and vision)

8.  Anthropos means “human” and metron means “measure”.
 Thus, It is the “measurement of human individuals.”
 It is the science of measurement of human body, provides
therapists to understand the complexities of the human form
and how is interfaces with its environment.

9.  Ergonomic program is one of the effective plan
taken into account by many employers.
 Increase efficiency of the organization
 Poorly design working environment can cause the
injurious outcome on three various systems on
humans’ body such as musculoskeletal system,
cardiovascular system and mental system.

11.  Risk factors are defined as actions or
circumstances that enhance the probability of
injury to the musculoskeletal system.
 Ergonomics Risk Factors (ERF) is situations
that exist or created intentionally or
unintentionally that could or might contribute
to results contravene or against the principles.

12. Ergonomics risk factors can be divided into
seven categories as follows,
 Forceful strains
 Awkward and static postures
 Vibration
 Repetition
 Duration
 Excessive pressure on nerve or soft tissue
 Extreme temperature

13.  Force is the amount of exertion needed by a
person to carry out a task or maintain control
of tools or equipments.
 It is so crucial to know how to apply this effort
to complete our activity.

16.  What is the proper posture ???
 Head, trunk, arms and legs
are aligned with one another.

17.  Awkward postures refer to a situation where the
body is under uncomfortable and away from
neutral position.
 Awkward or unsupported posture can be caused
by stretching or shortening of the connective and
nervous tissues.
 It is harmful whenever they are carried out in the
long time.

18.  Causes of Awkward Posture :-
 Poor design in work area
 Poorly considered hand tools
 Pushing ,pulling and carrying heavy load
 Performing tasks which require loads or body
parts

21.  Vibrations occur when an object oscillates or
rapidly moves back and forth about its
stationary point, like a swinging pendulum.
 Vibrations are defined by the frequency (how
fast the object is moving) and the magnitude
or amplitude (the distance of the movement).

24.  Repetitive movements can lead to overuse of muscles
and tendons.
 Muscles and tendons may be subjected to microtrauma
that causes pain.
 This is especially problematic if the repetitive
movements are performed in an awkward posture.
 In this case, muscles and tendons may actually rub
against other bony structures causing wear or
breakdown within the muscles and tendons.

26.  Duration factor is considered when the task is
repeated without any break.
 The longer duration of the task, the greater the
cumulative load on the tissues.
 Some remedies such as changing footrest, rest
breaks and etc can be effective in reducing
damages caused by this kind of ergonomic risk
factor.

27.  Contact stress occurs when an object presses on
soft tissue.
 The force imposed by excessive pressure on
small areas reduces blood flow and nerve
transition and can damage the soft tissue.
 It can occur from pressing against hard edges or
sharp surfaces, supporting excessive weight and
gripping tools.

29.  Muscles fatigue faster in hot conditions and
gripping objects or tools can become difficult
to maintain with sweaty palms.
 Alternating between tasks, or taking more
frequent breaks from the task may be
required when working in hot weather or
confined spaces.

30.  In cold conditions, blood flow to the extremities
is reduced and consequently muscle
performance is reduced.
 Loud noise can compromise attention to a task
and can create tension within the body.
 Poor visibility may lead to poor hand-eye co-
ordination during a task, or may place the body
in an awkward position while straining to see
properly.

33.  Types of ergonomics injury are referred as
physical and psychological.
 Physical ergonomic injuries :- Related to body size
and shape, fitness and strength, posture, the senses ,
stresses and strains on muscles, joint and nerves.
 Psychological ergonomics injury :- Related to mental
abilities, personality, knowledge and experience.

34.  The most common type of ergonomic injuries
and illnesses is known as musculoskeletal
disorders (MSDs) relating to physical injury .
 MSD’s have been associated with those work
related tasks including reaching, awkward
postures, lifting heavy objects, using
continuous force, working with vibrating
equipment, and performing repetitive
motions.

35.  Designing job in an effective and standard way.
Implementing job design needs to be based on
some criteria and aspects.
 Safety and healthy work practices at the site can
be also impressive which should be considered in
ergonomics program.
 Appropriate work practice and job design can be
considered as the fundamental solutions for
impeding ergonomic injuries.

37.  There are several elements required for
achieving a successful ergonomic program in a
workplace:

40. Training and education
employee perception, perceptions prompt
behavior repeated behaviors become
habits and the formed habits develop
attitudinal labels and culture among workers.

41. effective in shaping safety culture
develops the worker’s attitude
beneficial in reducing hazards and injuries
reduce the direct and indirect cost of injuries.

42.  Ergonomics for Therapist – Third edition , Karen
Jacobs
 Perspectives in Rehabilitation Ergonomics, edited by
Shrawan Kumar, Department of Physical Therapy,
University of Alberta, Edmonton, Canada
 International Journal of advances in Engineering and
Technology, March,2013
 University of Utah, Environmental Health & Safety
Department, Basic Principles of Ergonomics
 International labour Organization, Health and safety
at work Ergonomics, 6th June,2012