Two Streams - Egocentric and Ergonomic Models

Two Streams – Egocentric and Ergonomic
In Which One Are You Swimming?

Roger Kahler
Director and Principal Consultant
InterSafe
905 Stanley Street, East Brisbane, Qld 4169

Abstract
Occupational Health and Safety has a number of philosophical and conceptual streams that have
been many decades in their development.

The Egocentric Stream has its own models with accompanying words and associated meanings.
This stream, which has been a long time in its making, is defined by words such as “safe”,
“unsafe”, “careless”, “careful”, “cause” and “effect”. These words underpin the models and
thinking. The stream contains notions such as ‘accident prevention’ and ‘zero harm’. As a
consequence, this stream flows with the effect of producing a strong focus on human behaviour,
training and procedures. This stream has been flowing for at least 80 years.

The Ergonomic Stream also has its own models with accompanying words and associated
meanings. This stream is only some 60 years old in its making, having begun with the thinking of
people such as Gibson, Haddon and McDonald. Its focus is on damage as a consequence of an
energy exchange, multifactorial interactions producing damage, damage reduction, energy
management strategies, Pareto Principle and “is” thinking. As a consequence, this stream flows
with a strong scientific base and drives stronger engineering solutions to the problem of personal
damage.

The reader must make an informed decision as to which stream they will swim in. The streams are
different; they are not able to be integrated. Those who complete tasks and are damaged will be
the people who pay the price of the corporate position on such an important choice of streams.

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Two Streams – Egocentric and Ergonomic – In which one are you swimming? 2

Introduction
This paper is an attempt to model the world of occupational health and safety management as one
comprising two streams. Organisations (government and private) cannot avoid being in one of the
two streams. The streams exist and you are in them, whether you like it or not.

As managers and leaders, we need to observe and describe these streams and understand their
attributes, their strengths and weaknesses and decide if that is where one wants to be. What are
the streams’ distinctions? Each stream has to define its ultimate goal.

The paper will suggest the following goal is appropriate to both streams. The goal of OH&S
management activity is the minimisation of personal damage and, in particular, the elimination of
permanent damage to people, be it fatal or non-fatal permanent impairment.

The classification and quantification of personal damage from work is well defined1 2. These
research documents clearly illustrate that fatalities and non-fatal permanent damage are the critical
level of personal damage by any measure e.g.

a. pain and suffering;
b. functional impairment; or
c. direct and indirect costs to community, insurer, employer and employee.

Non-fatal Permanent Damage costs the most and much more than fatalities. However, fatalities
present “sovereign” risk to the deceased, his/her family, some line supervision and small
businesses. Sovereign risk is of such a magnitude that it destroys the viability / survivability of
people and organisations.

The dominant experience of an organisation is temporary and minor damage but there is very little
science to correlate lagging measures (All Injury Frequency Rates, Lost Time Injury Rates) and
patterns of such damage with the potential for an organisation to experience fatal and non-fatal
permanent damage.

With an expected annual 400+ traumatic work-related fatality cases and 60,000+ non-fatal
permanent damage cases costing in excess of some 90% of the total cost of all work-related
personal damage in Australia, the goal of OH&S activity is clear i.e. eliminate permanent personal
damage from work and, in the process, do not be distracted by lagging measures of minor damage
and temporary damage.

Lagging measures are a curse to the progression of clear thinking with respect to our stated goal,
even more so when people are financially rewarded for successfully managing minor and
temporary damage. Fatality rates in Australia are approximately 1:20,000-30,000 person years of
exposure, and non-fatal permanent damage rates at approximately 1:200 person years of
exposure. The OH&S practitioner, management, industry bodies and government must be able to
clearly articulate the features/qualities/characteristics of their “stream” of human energy, thought
and activity and its potential to influence the over-arching goal of the elimination of permanent
damage.

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This paper will suggest that there are two streams of energy/thought/activity which are mutually
exclusive. One is not the other and vice versa.

The model can be expanded to describe another supportive stream which can run parallel to the
two streams and is not to be confused with them. This is a “support” stream only. This stream is
the stream of organisational psychology with its associated organisational models built on such
thinking as –

• stratified systems thinking;
• values based organisations;
• team leadership / team membership principles;
• cultures – independent / interdependent;
• the role of systems, symbols and leadership behaviours.

The literature on this subject is extensive.3 4 5 6 7 8 9

The purpose of this paper is not to discuss the supportive stream of organisational psychology and
its associated models. This stream has the potential to create at one end of the spectrum, success
orientated cultures valuing team members, their contributions and create an organisation with
which people want to be associated.

At the other end of the spectrum are interdependent, failure avoidant cultures in which the
individual members act solo (with no sense of “team”) and respond to situations with inaction
because action may produce failure.

The purpose of this paper is to discuss the two streams which run parallel to the supportive
organisational psychology stream with these two streams having emerged over the last 60-80
years. Both streams have the goal of influencing the total amount of human damage which is
produced as a by product of work. However, only time (measured in decades) will tell which
stream is more likely to be effective in achieving the stated goal.

One stream will be called the “Egocentric” Stream. The other will be called the “Ergonomic”
Stream. Already, their names suggest that they may be quite different from each other.

The word ‘egocentric’ means “person centered”. The word “ergonomic” means “the laws or
measure of work”.

Preamble
The Egocentric Stream commenced formally in the 1920s. The Ergonomic Stream commenced in
the 1950s.

Before discussing the author’s opinion of 70-80 years of thought and development, the reader
must appreciate that only part of the story can be told in a short time.

There was significant international activity prior to the 1920s which demonstrated concern by
governments, industry organisations and individuals in response to damage which was occurring in
the workplace.

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Industrialisation could be deemed to have commenced in Britain about 1500 AD. Prior to this, the
country was predominantly agricultural supported by handcrafts but the transition had begun.
James Watt had the steam engine in operation in 1775, and the first cotton gin started in 1793.
The transition to industrialisation was not easy with there being riots between the hand spinners
and cotton gin operators.

With industrialisation came appalling living and working conditions. The British government
responded and introduced the Factory Inspectorate in 1833.

Some dates which show the emerging concern for worker safety on an international scale are:

1833 England – Government factory inspections established.
1844 England – Law enacted to provide fencing for mill gears and shafts. Lord Ashley’s “Great
Factory Act”.
1867 Massachusetts – Instituted factory inspection.
1869 Massachusetts – Established the first state bureau of labour statistics in order to determine
the kinds and causes of accidents.
1874 France – Law enacted providing for special inspection service of workshops.
1885 Germany – Bismarck prepared and had enacted the first compulsory compensation act for
workers. This act covered only sickness.
1921 International Labour Organization at Geneva set up a safety service.

It was about this time that the “Egocentric” Stream emerged with there being two defining
documents published by Heinrich of The Travelers Insurance Company who in 1926 established
the “Four to One” accident-cost ratio. The study of several thousand accidents indicated that
incidental costs of accidents such as loss of time and spoilage of material, are four times the
compensation and medical costs. In 1929, The Travelers Insurance Company published “The
Foundation of a Major Injury”. This research by Heinrich indicated that in a unit group of 330
similar accidents, all from the same proximate cause, 1 resulted in a major injury, 29 in minor
injuries, and 300 in no injuries whatsoever.

The “Egocentric” Stream had started flowing.

The “Egocentric” Stream
This stream has some very definable features. The “Egocentric” Stream contains the notion of
zero harm, unsafe acts and unsafe conditions and the belief that something must go wrong for an
accident to occur. From the stream’s source of 1:29:300, the stream has grown and developed
over time as it has flowed from its source in the 1920s to include systemic compliance, procedural
and training variations. Human activity is now expressed as “error”, “lapse”, “mistake” or some
variation of this theme.

The people who swim in this stream become strong proponents of individual accountability
because this is the nature of the stream – “you are accountable for your safety and the safety of
others”. The consequence of being in this stream is that simplistic statements are made for

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complex situations e.g. “keep your eyes on the path to prevent falls”, “maintain 3-points of contact
when descending and ascending access systems” and “lift correctly to protect your spinal column”.
Essentially, the controls are statements which can be projected onto an appropriate person at the
centre of an “accident” at the time of injury or pain being reported. The stream thinks in terms of
cause/effect with an accident being defined as an unplanned, undesired, unwanted event.

Let’s discuss the foundational 1:29:300 ratio.

It is interesting to explore how the ratio of incidents was initially produced and how it has been
modified by various others over time. Its original intent, as proposed by Heinrich, is interpreted as
follows.

It was seen as an aid to “accident” prevention and its intent was to prevent major injuries before
they occurred. A study by Heinrich suggested –

In a unit group of 330 accidents of the same kind and involving the same person, 300 resulted
in no injuries, 29 in minor injuries and 1 in a major lost-time injury.
Figure 1 graphically portrays the net result of this research.

Figure 1 Foundations of a major injury (Heinrich)
00.3 per cent of all accidents produce major injuries
08.8 per cent of all accidents produce minor injuries
90.9 per cent of all accidents produce no injuries

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Heinrich acknowledged the difficulty of the study of 5,000 major (lost time) injuries due to the
absence of data. Two cases explain his logic.

Case 1
An employee, in going to and from work, took a short cut that obliged him to climb a fence and
cross a railroad siding that was a part of the plant premises. Cars spotted at this point
frequently prevented a clear vision of the tracks, and the noise of the plant machinery (24-hour
operation) made it difficult to hear warning whistles and bells. One day, at noon, this man
stepped from behind a freight car directly into the path of an oncoming engine, was struck and
badly injured. Crossing the tracks at this point was forbidden, and notices to that effect were
posted. A fence was provided. Trainmen used whistles and bells. In short, the situation was
normal, except for non-enforcement of instructions. The employee admitted that he had
crossed the tracks four times a day for two and one-half years – or approximately three
thousand times prior to his injury – and that he had stumbled, fallen, had to jump hurriedly
aside, and otherwise had narrowly escaped injury approximately five hundred times. His first-
aid record for the period showed 38 cuts and abrasions sustained while climbing the fence and
stumbling over the tracks. The ratio was estimated to be 500-38-1.
Note: The intent of the above and following examples is to show only the numerical relation
between the major injury, the minor injury, and the no-injury accident. The number of unsafe
acts or conditions preceding the accident could only be guessed.
Case 2
An employee slipped and fell on a wet floor and bruised his kneecap. For more than six years,
it had been the practice to wet down too great an area of floor space at one time and to delay
unnecessarily the process of wiping up. Slipping on the part of his employee was a daily
occurrence. Estimated ratio 1800-1-0.

The discerning reader may be able to see the strengths and weaknesses to Heinrich’s logic but it
was always Heinrich’s intent to suggest that there is a predictive base to lost time injuries.

Frank E Bird in 1969 “built” upon the 300:29:1 ratio but with a different logic applying. He made an
analysis of 1.75million accident reports from 297 American insurers. After an additional 400 hours
of confidential interviews to establish the base of the triangle, he concluded:

The 1-10-30-600 relationships in the ratio would seem to indicate quite clearly how foolish it is
to direct our total effort at the relatively few events terminating in serious or disabling injury
when there are 630 property damage or no-loss incidents occurring that provide a much larger
basis for more effective control of total accident losses.

Fatal, Disabling, LTI
Serious or Disabling ANSI Z16.1
1 (Fatal, disabilities, LTI’s)

Minor Injuries (first aid)
10

Property Damage Accidents
4,000 hours of 30 (unrelated to injuries)
interviewing
involved Incidents with No Visible Injury or Damage
600 that could have produced injury or property
damage.

Figure 2 The Bird accident ratio study

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The stream of egocentricity was by 1970 embracing the notion of managing and measuring the
bottom layers of the incident triangle on the journey of “total loss control”. The thinking being
embodied was emotionally attractive to industry. So attractive that in the last decade “total loss
control” has become “zero harm”. However, Heinrich and others became a little horrified at Bird’s
suggestion of “total loss control” and made the following profound statement but it was too little too
late because the stream was flowing and, in its momentum, drowned their voices.

It also does not mean, as we have too often interpreted it to mean, that the causes of frequency
are the same as the causes of severe injuries.
Our ratios and figures in this area have confused us. We have typically believed a 1-29-300
ratio, believed it might apply to all kinds of accident types and causes, and then seen national
figures as in Figure 3 that show that different things cause severe injuries than the things that
cause minor injuries. Obviously then there are different ratios for different accident types, for
different jobs, for different people etc. The triangle for the accident type “electricity” is a different
looking triangle than the one for “handling materials”.
Common sense dictates totally different relationships in different types of work. For instance ,
the steel erector would no doubt have a different ratio from the office worker.
This very difference might lead us to a new conclusion. Perhaps circumstances which produce
the severe accident are different from those that produce the minor accident.
Safety workers for years have been attacking frequency in the belief that severity would be
reduced as a by-product. As a result, our frequency rates nationwide have been reduced much
more than have our severity rates.
Type of Accident Temp Total, % Perm. Partial, % Perm. Total, %
Handling materials 24.3 20.9 5.6
Falls 18.1 16.2 15.9
Falling objects 10.4 8.4 18.1
Machines 11.9 25.0 9.1
Vehicles 8.5 8.4 23.0
Hand Tools 8.1 7.8 1.1
Electricity 3.5 2.5 13.4
Other 15.2 10.8 13.8
Figure 3 Accident types and severity

The other significant contribution by Heinrich to the “Egocentric” Stream of accident prevention is
summarised in their axioms of industrial safety as follows3.

1. The occurrence of an injury invariably results from a completed sequence of factors – the
last one of these being the accident itself. The accident in turn is invariably caused or
permitted directly by the unsafe act of a person and/or a mechanical or physical hazard.
2. The unsafe acts of persons are responsible for a majority of accidents.
3. The person who suffers a disabling injury caused by an unsafe act, in the average case
has had over 300 narrow escapes from serious injury as a result of committing the very
same unsafe act. Likewise, persons are exposed to mechanical hazards hundreds of
times before they suffer injury.
4. The severity of an injury is largely fortuitous – the occurrence of the accident that results in
injury is largely preventable.
5. The four basic motives or reasons for the occurrence of unsafe acts provide a guide to the
selection of appropriate corrective measures. (The four basic reasons are –

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a. Improper attitude
b. Lack of knowledge/skill
c. Physical unsuitability
d. Improper mechanical or physical environment.)
6. Four basic methods are available for preventing accidents – engineering revision,
persuasion and appeal, personnel adjustment, and discipline.
7. Methods of most value in accident prevention are analogous with the methods required for
the control of the quality, cost and quantity of production.
8. Management has the best opportunity and ability to initiate the work of prevention,
therefore it should assume the responsibility.
9. The supervisor or foreman is the key man in industrial accident prevention. His application
of the art of supervision to the control of worker performance is the factor of greatest
influence in successful accident prevention. It can be expressed and taught as a simple
four-step formula.
10. The humanitarian incentive for preventing accidental injury is supplemented by two
powerful economic factors: (1) the safe establishment is efficient productively and the
unsafe establishment is inefficient; (2) the direct employer cost of industrial injuries for
compensation claims and for medical treatment is but one-fifth of the total cost which the
employer must pay.

The Domino Theory emerged (Figure 4 and Figure 5) and was later developed and modified by
others.

Figure 4 The five factors in the accident sequence

Figure 5 The injury is caused by the action of preceding factors

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A most significant influence which coloured and flavoured the “Egocentric” Stream was the thinking
of “unsafe acts” and “unsafe conditions” as fundamental to incidents. A ratio of 88:10:2 was
proposed in which 88% of accidents are attributable to unsafe acts; 10% of accidents are
attributable to unsafe conditions; and 2% of accidents are unpreventable.

The Domino Theory of unsafe acts and conditions was linked to the notion that 88% of accidents
were caused by unsafe acts and, by implication, human error.

To arrive at this ratio of unsafe acts and conditions, Heinrich had studied 75,000 cases (12,000
insurance records and 63,000 plant owners’ records). His logic is expressed as follows.

It was discovered that 25 per cent of all accidents would, according to usual but improper
methods of analysis, be charged to defective or dangerous physical or mechanical conditions,
but that in reality the causes of many accidents of this group were either wholly or chiefly man
failure and only partly physical or mechanical. This group, therefore, was found actually to be
10 per cent instead of 25 per cent. This difference (15 per cent) added to the 73 percent of
causes that are obviously of a man-failure nature, gives a total of 88 per cent of all industrial
accidents that are caused primarily by the unsafe acts of persons. Check analyses, made
subsequently on a smaller scale, produce approximately the same ratios.
In this research major responsibility for each accident was assigned either to the unsafe act of a
person or to an unsafe mechanical condition, but in no case were both personal and mechanical
causes charged.

The famous 88:10:2 ratio was now born with variations emerging by other researchers e.g. 85:15,
88:12 etc. At the same time Heinrich published his 88:10:2 ratio, other studies by the National
Safety Council (NSC) were challenging the notion and recognising a possible multi-factorial nature
to damage. Heinrich himself states:

In addition to the research that resulted in the development of the above ratios, other studies
have been made, one of chief interest being that conducted by the NSC. This showed unsafe
acts for 87 per cent of the cases and mechanical causes for 78 per cent. An analysis made in
1955 of cases reported by the state of Pennsylvania showed an unsafe act for 82.6 per cent
and a mechanical cause for approximately 89 per cent of all accidents. One reason for the
difference in the number of accidents charged to personal or mechanical causes in the three
studies described above is that, in the last two, the method permitted both kinds of causes to be
assigned for the same accident, whereas in the study first mentioned only the cause of major
importance was assigned.

Ratios of 83:89 were being proposed by the NSC.

All of this debate could have been resolved if the parties had recognised that 100% of all incidents
involve at least the behaviour (present/absent) of people, 100% involve an aspect of the equipment
(present/absent) and the work environment (present/absent).

However, the stream was now flowing strongly and was appealing with its notions of –

a) 88:10:2 ratios,
b) “unsafe” acts and “unsafe” conditions, and
c) a ratio of numbers depicted as a triangle with management and measurement of its base
being foundational to government and organisational activity.

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The ratio of 88:10:2 was and is foundational to the behavioural based safety programmes of today.

These original authors were beginning to be challenged over the next 50 years as various other
models were developed e.g. Weaver updated the Domino Theory to explore predisposing
supervisory management issues associated with “unsafe” acts and conditions Figure 6).

WHAT
Caused the
accident leading to

Unsafe Act and/or
Fault of Person
Heredity and
Environment

Condition

Accident

Injury
Symptoms of
Operational Error

WHY WHETHER
The unsafe act and/or Supervisory – management had
condition was permitted the safety knowledge to prevent
the accident

Locate and Define Operational Error

Figure 6 Weaver’s updated dominoes

Dr Michael Zabetakis developed the notion of “cause” being an unplanned release of energy.
Multiple causative models were emerging. Hugh Douglas of Imperial Oil Company developed the
Stair Step Model being a “cause” and “effect” sequence.

There were behavioural based models appearing e.g. the life change theory in which it was
proposed that at times people are more liable to be involved in an accident than at other times.
There was the Goal Freedom Alertness Model in which accidents were recorded as low quality
work behaviour and that there was a need to raise the level of behavioural quality which raised the
level of alertness in a rewarding psychological climate.

It can be observed that all of these models have a strong focus on the individual and a strong
focus on cause/effect thinking with “unsafe” acts and “unsafe” conditions prevailing.

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Heinrich’s work was strongly endorsed and supported by Julianne Brown, Dan Peterson and
others.

With these developments of various models, the frustration of the original authors including
Heinrich became evident in the following extract.

It seems almost unbelievable that with the knowledge that people cause most accidents,
knowledge that has been available since the early 1930s, so much time and effort since that
time has been spent by industry with primary, often total, attention on physical conditions. It is
even more unbelievable that in 1970, some 38 years after this knowledge was available, the
United States would turn to a national approach based almost entirely upon the control of
physical conditions: the Occupational Safety and Health Act (OSHA).
Unbelievable or not, this is precisely what transpired. With almost universal belief in the
principle that safety is primarily determined by people, the principle was almost totally rejected
by the Congress, who chose to legislate a law based upon a totally opposite principle: that
accidents are caused by conditions – by things.

The Bird and Weaver models were increasing the emphasis of management as prime causative
agents in all accidents. The notion of “cause” was expanding in its definition with the “basic” cause
being the unsafe act/unsafe condition, the “sub” cause being the specific “fault” of the person and
the “underlying” cause being the supervisor and managerial faults and the social and
environmental conditions outside the workplace. Perhaps the reader can note some similarities
and differences to the philosophy, models and underlying words of their own situation.

In addition, Bird’s notion of managing the “bottom” of the incident triangle and the associated
thought of “total loss control” appears to have gone out of favour in the 1980s and 1990s but in this
last decade has resurfaced and been rebranded as “zero harm”. Zero harm means no damage to
anybody, ever! The zero harm goal is contrary to the suggested goal of this paper.

Much more could be said about the Egocentric Stream but some of its characteristics are
described. There are some adaptations and challenges but the fundamental thinking continues to
be embraced by many, many organisations.

The Ergonomic Stream
This Ergonomic Stream is different to the Egocentric Stream and it has very definable features to
describe it. The Egocentric Stream’s goal of accident prevention is significantly extended to the
goal of damage reduction. The significance of damage reduction measures such as Personal
Protective Equipment, smoke detectors, earth leakage relays, seat belts and roll over protective
structures is not viewed as lowest on the hierarchy of controls but as an effective strategy
scientifically proven to reduce damage.

Damaging occurrences (versus incidents) are described in terms of what “is” and “is not”;
hypotheses are formed and tested and damage is viewed as a complex interaction of the elements
of people, equipment and environment. Damage is expressed as a consequence of an energy
exchange and the controls emerge from a consideration of energy management strategies but not
to the neglect of the systemic issues which can ensure that those controls are in place to operate
when required.

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People’s behaviours are expressed in terms of what they “did” and “did not do”, what they “knew”
and “did not know” and what skills they “had” and “did not have”.

Observed behaviours are not judged in hindsight as “unsafe” or “unreasonable” but are understood
in terms of the complex interaction of the human sensory systems, the information organisers of a
person and the role of expectation and mental set. People’s information processing systems are
such that they are often not cognisant of when they have not noted appropriate information to allow
a task to be completed successfully and free from damage. For example, the Ergocentric Stream’s
notion of “inattentiveness” is replaced with “divided attention” with the idea being that people are
always attending to something.

The words “injury” and “disease” are replaced with the word “damage” wherein damage to tissue
and function (physical, emotional) is described as a consequence of an energy exchange in which
the energy exceeds tolerable limits of the structure. This implies the concept of dose (an
energy/time interaction) when considering the damage to people.

Damage can be classified as multiple fatality, single fatality, non-fatal permanent damage,
temporary and minor with it being clearly understood that the patterns associated with each of
those levels of damage are different and the patterns involve different phenomena. When damage
occurs the associated time sequence moves through very different phases of “stable”,
“metastable”, “unstable”, “damage”, “repair” and “recovery”. The time zones are preceded by
predisposing factors which can extend over months or years and derive from a complex set of
areas.

Cause/Effect thinking is replaced by “is” thinking whereby the factors involved in the immediate
circumstances of the incident are derived from the elements of people, equipment and the
environment interacting and resulting in a damaging occurrence. Those factors are described as
“Essential” with all factors considered equal in their ‘essentialness’ to the unfolding of the time line
but viewed differently in terms of their future controllability. “Unsafe acts” and “unsafe conditions”
are replaced by “essential” acts and conditions (present/absent) where no value judgement is
required.

The scientific concepts of taxonomy, hypothesis forming and testing and modelling are viewed as
interacting concepts. A hypothesis is simply a testable proposition; a model is a conceptual frame
of reference for organising one’s thinking. Taxonomy is the scientific method of classification
starting with observation and description in which damaging occurrences are sorted into groups
wherein it is possible to observe the relative importance of the different energies and their
mechanisms. In this Ergonomic Stream it is necessary for taxonomies to be developed and
analysed using appropriate models so that hypotheses can be formed and tested as to the effect of
changes which are implemented.

What is the history of this Ergonomic Stream?

The Ergonomic Stream is a much younger stream than the Egocentric Stream, being
approximately 60 years old, finding its origins in approximately 1950 when John E Gordon
recognised that injuries, when broadly considered, were a problem in medical ecology. He
suggested that injuries in many respects behave as classic infectious diseases in that they share

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point epidemics, long term trends, socioeconomic patterns etc. The origin of the Ergonomic
Stream had begun.

Prior to 1950, the medical profession had developed a host, agent and environment model
(equivalent to the current use of people, equipment and environment in the industrial sector).
Gibson, (familiar with the host, agent and environment model) in 1961 clearly identified and
described the necessary agent of injuries as a consequence of an energy exchange. These
energies were identified as gravitational mechanical, radiant, thermal and chemical.10 11

In 1961, Gibson12 stated:

Man... responds... to the flux of energies which surround him – gravitational and mechanical,
radiant, thermal, and chemical. Some limited fields and ranges of energy provide stimuli for his
sense organs; others induce physiological adjustments; still others produce injury...
Injuries to a living organism can be produced only by some energy interchange. Consequently,
a most effective way of classifying sources of injury is according to the forms of physical energy
involved. The analysis can thus be exhaustive and conceptually clear. Physical energy is
either mechanical, thermal, radiant, chemical, or electrical.

Three months later, Haddon arrived at the same conclusion independent of Gibson that “several
kinds of energy are the necessary specific causes of the injury” and that “these energies interfere
with normal body energy exchanges”.13 14 15 For example, frostbite is considered an absence of
thermal energy.

Haddon recognised that rates and intensity of energy exchanges were critical in explaining the
damage experienced. The concept was linked to injury thresholds and was supported by the work
of such others as Col Staff and Hugh De Haven.16 De Haven realised the central importance for
injury thresholds and energy exchanges. In this regard he considered these thresholds together
with the intensity and duration of the energy exchange determined the injury outcome. De Haven
has contributed significantly to the modern field of damage reduction devices and we experience
the benefits in modern motor vehicles and our driving environments.

Haddon’s theories continued to develop to including a model of “pre-event, event and post event”.
This model became the first dimension of a matrix known as the “Haddon matrix”. He added
another dimension to the matrix of human, vehicle and environment. He was involved in motor
vehicle research and, hence, his extension of the medical model of host, agent and environment.
This gave a two dimensional matrix. Some authors have extended the matrix to three dimensions.

In 1962, Haddon’s thinking extended again to include a set of strategies for managing energy
exchanges. The strategies were applicable to the pre-event, event and post even phases of an
incident time line. He published ten strategies, as summarised below.17

1. Do not marshal the energy
2. Reduce the energy marshalled
3. Prevent the release of the energy
4. Modify the time/rate of release
5. Separate the energy released from people in time/space

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6. Separate the energy released from people by a barrier
7. Modify the surface contacted
8. Strengthen the structure against the energy exchange
9. Rapidly detect and evaluate potential damage arising from the energy exchange
10. Rehabilitation

By the 1960s, the concepts of damage, energy exchanges, host agent and environment pre-event,
event and post-event time lines, and the scientific process of taxonomy, modelling and hypothesis
forming and testing were beginning to define this stream.

A new researcher appeared on the scene. He in the 1960’s as a young engineer, Geoff
McDonald, who commenced work at the University of Queensland on Australian tractor fatalities.
The concepts deriving from the work of Haddon, Gibson, Staff, De Haven etc were now about to be
developed to the next level. The “event” phase of Haddon’s work was extended to include the
concepts of a stable time zone, a metastable time zone, an unstable time zone and a damage time
zone. The term “Damage Reduction” was developed to challenge the thinking beyond the stable
time zone. It is at the stable time zone that Accident Prevention thinking generally stops and does
not progress in a structured way beyond it.

Damage to people was classified as Class I (permanent), Class II (temporary) and Class III
(minor). It was recognised that the Pareto Principal of 80/20 readily applied in which 90% of the
cost of work-related damage had come from less than 10% of the recorded cases and that the
largest cost was associated with Class I non-fatal damage. This ratio was first reported by the
Australian Industry Commission in 199518. This 1995 document costed the damage to the
individual and the community as well as the employer and insurer. Suddenly, 90% of the cost of
work related damage was associated with those few cases of non-fatal but permanently impaired
people.

Taxonomies or pattern analyses were being completed on the basis of the energy which damaged
the tissue or resulted in loss of function. It became clear that the pattern of Class I damage was
different to the pattern of Class II and Class III. The Haddon five energies were expanded to some
fourteen describers e.g. human, gravitational, vehicle, thermal, chemical etc. In addition, the
stream was beginning to flow in the direction where the words “incident” and “accident” were
replaced with “damaging” and “non-damaging” occurrences. Clear alternatives were being given to
the understanding of human interactions with equipment and environment. A model of information
detection (the sensory system of the person), information processing (the role of expectation and
mental set) and decision making emerged. The language was increasingly becoming value neutral
as it was recognised that words have two components e.g. a psychological component of “affect”
(the emotional response of the hearer to the word) as well as the “meaning” of the word.

McDonald has built dramatically upon the thinking of Haddon etc. His thinking could potentially
define occupational health and safety for the next 50-100 years.

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Summary
These two streams are different from each other. The Egocentric Stream has very wide
acceptance because of its appeal to imperfect man. The Ergonomic Stream has a strong basis in
the scientific method. Which stream will deliver the stated goal of the elimination of permanent
personal damage from work and the systematic reduction of minor and temporary damage? The
answer to that is not known. We do know that fatality rates are decreasing. For example, when
the Sydney Harbour Bridge was constructed, there was approximately one person killed for every
800 person years of work completed compared with an industry that now requires 20,000 person
years of exposure for one fatality.

We do know that non-fatal permanent damage is not decreasing and, in some areas, its rate is
increasing. Perhaps the future draws on the strengths of each stream. However, organisations
are not even recognising the existence of at least two very different streams.

The author has a particular view as to which stream is most likely to be successful but has no
measures to support the view that the ergonomic stream of is the appropriate stream.

There is a revulsion by the author at some of the notions which are being proposed as a
consequence of the Egocentric Stream e.g. a person falls when descending a fixed vertical ladder
and the control is expressed in terms of “they did not maintain three points of contact and need to
improve their behaviour”.

What we do know is this – the World Health Organisation has stated that personal damage at work
is one of the world’s worst researched epidemics. The medical profession is the source of the
Ergonomic Stream. The Ergonomic Stream has resulted in such things as improved
crashworthiness of vehicles and our environments, Residual Current Devices, fall arrest systems,
improved emergency response capability etc. The world of the medical profession with its strong
scientific approach has over a 100-year period increased the average life expectancy of a male in
Australia from approximately 50-55 years to 80 years. Therefore, any move from the Egocentric
Stream to the Ergonomic Stream is going to require one of those most strange of human attributes
called faith.

Faith in the Ergonomic Stream can become that which prevails and carries until the reality of the
goal is experienced. Herein lies the challenge. Have you ever considered or thought about the
attributes/describers of your stream, of its underlying philosophy, thought and activity and whether
it is appropriate for the attainment of the stated goal? If the leaders of organisations do not
contemplate these questions, then it is predictable that the epidemic will continue.

The person who falls and is permanently damaged while descending a fixed vertical ladder
eventually pays the price – that person is the damaged one. We must ensure that our corporate
thinking, our models and our information organisers have this man’s work organised in such a way
that if a person has to move between two levels to achieve task, his interaction with the work
environments are entirely compatible with their imperfect humanity.

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1
National Data Set For Compensation Based Statistics, 3rd Edition, July 2004, Australian National
Occupational Health and Safety Commission, Canberra.
2
The Cost Of Work-Related Injury And Illness For Australian Employers, Workers And The
Community: 2005-2006, Australian Safety and Compensation Council, 2009.
3
Heinrich, H.W., Industrial Accident Prevention - A Scientific Approach, 4th Edition, 1959, McGraw-
Hill Book Co., New York
4
McDonald, I, Burke, C., Stewart, K., Systems Leadership, Creating Positive Organisations, 2006,
Gower Publishing Ltd., England
5
Senge, P.M., Kleiner, A., Roberts, C., Ross, R.B., Smith, B.J., The Fifth Discipline Fieldbook, Nicholas
Brealey Publishing, London, 1997
6
Jaques, E. & Clement, S.D., Executive Leadership: A Practical Guide To Managing Complexity,
Cason Hall & Co., 1996
7
Hunt, J.W., Managing People At Work: A Manager's Guide To Behaviour In Organisations, Second
Edition, McGraw-Hill Book Company, 1986
8
Kepner, C.H. & Tregoe, B.B., The New Rational Manager, Princeton Research Press, 1981
9
Recardo, R., Wade, D., Mention, C., Jolly, J., Teams, Gulf Publishing, 1996
10
Runyan, Carol W., Using The Haddon Matrix: Introducing The Third Dimension, J. Injury Prevention,
1998:4:302-307
11
Haddon, W., Advances in the Epidemiology of Injuries as a Basis for Public Policy, Public Health
Reports, Vol 95, No. 5, September-October 1980, pp411-421
12
Gibson, J.J., The Contribution of Experimental Psychology to the Formulation of the Problem of
Safety – A Brief for Basis Research, In Behavioural approaches to accident research. Association for
the Aid of Crippled Children, New York, 1961, pp 77-89
13
Haddon, W., Jr., Suchman, E.A., and Klein, D.: Accident Research Methods and Approaches. Harper
& Row, Publishers, New York, 1964.
14
Haddon, W., Jr.: A Note Concerning Accident Theory and Research with Special Reference to
Motor Vehicle Accidents, Ann NY Acad Sci 107: 635-646, May 22, 1963
15
Haddon, W., Jr.: The prevention of Accidents In Preventive Medicine, edited by D.W. Clark and B.
MacMahon. Little, Brown and Company, Boston, 1967, pp 591-621
16
De Haven, H.: The Relationship of Injuries to Structure in Survivable Aircraft Accidents, Committee
on Aviation Medicine Report No. 440, Cornell University Medical College, New York, 1945.
17
Haddon, W., Jr.: On the Escape of Tigers: An Ecologic Note, Am j Public Health 60: 2229-2234,
December 1970
18
Industry Commission, Work Health & Safety, An Inquiry Into Occupational Health & Safety. Vol 1:
Report, Report No. 47. Industry Commission, Australia, September 1995

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