Cumulative Trauma Disorder
&
Upper Extremity Conditions
Cumulative Trauma DisorderCumulative Trauma DisorderDefinitionDefinition
Mechanical Events Leading to the Alteration of Tissue Homeostasis– Typically through prolonged exposure– Overexertion– Excessive Movements– Awkward or Irregular Postures
Cumulative Trauma DisorderCumulative Trauma DisorderScopeScope
Hipprocates
Affections
“What occupation does he follow?”
Ramazzini17th Century Manuscript
Diseases of Workers
Cumulative Trauma DisorderCumulative Trauma DisorderScopeScope
Increasing prevalence of disorders Not new clinical syndromes Major concern
– Industry– Insurance Carriers– Health-care Providers– State and Federal Government
Not solely a product of the modern technology
Cumulative Trauma DisorderCumulative Trauma DisorderScopeScope
Despite the proliferation of keyboards in modern life (i.e. computers) there has been no increase of CTS. The incidence remains at ~5%
Cumulative Trauma DisorderCumulative Trauma DisorderScopeScope
CTD not important to the medical treatment of the patient except perhaps to recommend activity modification
Legally, this delineation may generate:– Adversary– Expense– Vitriolic Emotions
Cumulative Trauma DisorderCumulative Trauma DisorderScopeScope
US Bureau of Statistics
List of new occupational illnesses associated with repetitive trauma– 1980: 23,300– 1983: 26,000– 1984: 34,700
Cumulative Trauma DisorderCumulative Trauma DisorderCausationCausation
Cumulative trauma disorders due to performance of repetitive tasks account for more than 50% of all occupational illnesses in the United States today
Rempel 1992
Cumulative Trauma DisorderCumulative Trauma DisorderCausationCausation
Cumulative trauma disorders are frequently responsible for the development of occupational neuropathy
Zimmerman 1992
Carpal Tunnel Syndrome & Typing
Cumulative Trauma DisorderCumulative Trauma DisorderCausationCausation
All such statistics must be viewed cautiously, as this tends to represent the reporting of conditions, not an actual delineation of the conditions as etiologically bound (caused by) to the exposure.
Does having a condition prove causation?
Cumulative Trauma DisorderCumulative Trauma DisorderCausationCausation
Ergo Proctor Ergo Semper– Subsequence does not prove ConsequenceMerely having the problem or
symptoms manifest themselves during work hours does not automatically mean the problem arose out of and in the course and scope of one’s employment and thus be deemed as compensable.
Cumulative Trauma DisorderCumulative Trauma DisorderCausation: Which came first, the chicken or the eggCausation: Which came first, the chicken or the egg
Cumulative Trauma DisorderCumulative Trauma DisorderCausationCausation
Are epidemiologic surveys identifying diseases or merely cataloging complaints?
And if the disease is diagnosed, is there a causal link, an exacerbating link to the work exposure, or merely an enhanced awareness of the condition?
What about confounding variables?
Cumulative Trauma DisorderCumulative Trauma DisorderCausationCausation
Has the exposure even been quantified?
How much repetition? How much force
Most assessments are qualitative at best.
Compare the modern keyboard to the old typewriters prior to even the electric typewriter
Cumulative Trauma DisorderCumulative Trauma DisorderComorbiditiesComorbidities
Age Gender Smoking Weight Disease
– Diabetes– Hypothyroid
Avocational Pursuits
Conditioning– Exercise increases
joint laxity ergo diminishes risk of injury
Psychosocial– Job Satisfaction
– Marital issues
Cumulative Trauma DisorderCumulative Trauma DisorderScope: Turkey ProcessorsScope: Turkey Processors
This is an area of medical controversy, the intensity of which as demonstrated by the five days of medical evidence I heard would be worthy of medieval theology. For which, I am none the wiser.
Senior British Judge 1994
Cumulative Trauma DisorderCumulative Trauma DisorderHistory: LegalHistory: Legal
Exposure: causal vs exacerbatory vs awareness No uniformity in categorizing occupational
conditions
Liability of an industrial carrier may vary
Adding to the confusion is the poor, yet evolving evidence as to causation of diagnoses
Cumulative Trauma DisorderCumulative Trauma DisorderDefinitionsDefinitions
Synonyms– Repetitive motion disease– Repetition strain disorder/ injury (RSI)– Upper limb syndrome– Shoulder-arm syndrome– Overuse syndrome– Work related disorder– Cervico-brachial syndromes
Cumulative Trauma DisorderCumulative Trauma DisorderDefinitions: DescriptiveDefinitions: Descriptive
Overuse Syndrome– Activity induced aches and pains – Alleviated by:
Periods of Rest Activity Modification
– Effects may be transient or permanent– Concept of metaplasia
Cumulative Trauma DisorderCumulative Trauma DisorderDefinitions: MalignedDefinitions: Maligned
Repetitive Strain Injury (RSI) – Implies causation– Usurped by popular usage and the media – Ascribed to the Americans– Australian Experience
Illuminates the foibles of applying medical and legal principles to poorly defined terms and processes
Cumulative Trauma DisorderCumulative Trauma DisorderDefinitions: MalignedDefinitions: Maligned
Repetitive Strain Injury (RSI) RSI represents a psychosomatic disorder
associated with psychological, social, or economic issues
Millender 1992
Repetitive Strain InjuryRepetitive Strain InjuryHistory: AustraliaHistory: Australia
Epidemic of 1980s Occupational Arm
Pain Attributed to rapid,
repetitious use– Initially on a keyboard
Repetitive Strain InjuryRepetitive Strain InjuryHistory: AustraliaHistory: Australia
Collection of Symptoms Affecting the Upper extremity– Weakness– Paresthesias– Swelling– Pain
Pain, while often consistent in a given patient, is not consistent among patients
Repetitive Strain InjuryRepetitive Strain InjuryHistory: AustraliaHistory: Australia
Pain, while often consistent in a given patient, is not consistent among patients
– No primary objective findings except tenderness
– Does not conform to any known:Neurologic pathwaysAnatomic structuresPathophysiologic pattern
Repetitive Strain Injury Repetitive Strain Injury History: AustraliaHistory: Australia
Affected– Young to middle
aged– Predominantly
female– Occupations
Low-paying Monotonous Low prestige
Repetitive Strain InjuryRepetitive Strain InjuryHistory: AustraliaHistory: Australia
Clinical studies are negative:– Biochemistry
Hematology– Radiography
Thermography Bone scan
– Electromyography– Histopathology
Biopsies
Repetitive Strain InjuryRepetitive Strain InjuryHistory: AustraliaHistory: Australia
Fails to respond to:– Rest– Splinting– Physical therapy– Anti-inflammatory
medications– Surgery
Repetitive Strain InjuryRepetitive Strain InjuryHistory: AustraliaHistory: Australia
Lack of clinical evidence
Epidemic spreads Complicity of:
– Physicians– Lawyers– Employers– Government
Repetitive Strain InjuryRepetitive Strain Injury History: AustraliaHistory: Australia
Epidemic spreads: Industries with no change for decades in manual tasks and productivity
– Data Processors– Process Workers– Typists– Clerks– Cashiers– Bank Tellers– Musicians– Packers– Machinists
Repetitive Strain InjuryRepetitive Strain InjuryHistory: AustraliaHistory: Australia
Initially attributed to rapid, repetitious use a keyboard:– Keystroke Occuptation Incidence– Lowest Telephonists 34 %– Low Clerks 28 %– Highest Keyboardists 3.4%
Cumulative Trauma DisorderCumulative Trauma Disorder PsychologyPsychology
Australia disavows RSIClaims disappear
Industry created around RSI disintegrates
Cumulative Trauma DisorderCumulative Trauma DisorderPsychologyPsychology
Repetitive Strain Injury (RSI) RSI represents a psychosomatic disorder
associated with psychological, social, or economic issues
Millender 1992
Cumulative Trauma DisorderCumulative Trauma Disorder DiagnosisDiagnosis
When Delineating between Factitious, Psychological, & Organic Syndromes
Caution:
What’s the difference between God and a doctor?
God knows he’s not a doctor
Cumulative Trauma DisorderCumulative Trauma Disorder Psychologic CorrelatesPsychologic Correlates
Back Pain &
Work Incapacity
– A belief by patients that their work had injured their backs
– Job dissatisfaction
Magora
Nachemson
Bigos
Cumulative Trauma DisorderCumulative Trauma Disorder Low Back PainLow Back Pain
85% – Affects adult population
Miss 1 day of work
5% – Source of pain identified
50% – Patients receive surgical
intervention
Cumulative Trauma DisorderCumulative Trauma Disorder Making a DiagnosisMaking a Diagnosis
Clearly defined & distinguishable subjective clinical symptoms
Reproducible, objective physical findings
Recognizable pathologic findings
Response to accepted and proven forms of effective physical treatments
Cumulative Trauma DisorderCumulative Trauma Disorder Playing GodPlaying God
Avoid labels– Terms like CTD, RSI
suggest mechanisms but are not diagnoses
Cumulative Trauma DisorderCumulative Trauma Disorder Playing GodPlaying God
Avoid labels– Terms like CTD, RSI
suggest mechanisms but are not diagnoses
– Inappropriate use of terms invalidate otherwise defined processes
Fibromyalgia – A defined syndrome– Specific diagnostic
criterion– Widespread use
Aches Fatigue
– Connotation Psychiatric Factitious disorder
Cumulative Trauma DisorderCumulative Trauma DisorderPlaying GodPlaying God
Avoid labels– Terms like CTD, RSI
suggest mechanisms but are not diagnoses
– Inappropriate use of terms invalidate otherwise defined processes
Pain is a recognized diagnosis, use it
ICD-9-CM– 729.5 Pain in Limb– Includes:
Arm pain Finger pain Leg pain Foot pain
Cumulative Trauma DisorderCumulative Trauma Disorder EvidenceEvidence
Let’s review specific diagnoses
Adding to the confusion is the poor, yet evolving evidence as to causation of diagnoses
Cumulative Trauma DisorderCumulative Trauma Disorder
“There can be little doubt that in patients who develop (this condition) use of the hand will be painful…but there is no clinical evidence to support the view that the use of the hand alters the natural history of the condition in any way whatsoever, though the symptoms are clearly relieved by rest…highly-repetitive work should be avoided (to) simply diminish symptomatology.
Kay NR. De Quervain’s disease. Changing pathology or changing perception? J Hand Surg Br 2000; 25:65-69
Cumulative Trauma DisorderCumulative Trauma DisorderDiagnosesDiagnoses
Nerves: Peripheral Entrapment
– Carpal Tunnel Syndrome– Cubital Tunnel Syndrome– Thoracic Outlet Syndrome
Tendons– Trigger Digits– de Quervain’s Tendonitis
Skin– Blisters– Calluses
Muscles (Enthesopathy)– Lateral Epicondylitis
(Tennis Elbow)– Shoulder Impingement
(Rotator Cuff Disease) Joint & Bone
– Arthritis– Stress Fractures– Ganglions
Vascular– White Finger Syndrome
Cumulative Trauma DisorderCumulative Trauma Disorder Analyzing Occupational Risk FactorsAnalyzing Occupational Risk Factors
Combination of Risk Factors (Load & Rate)– Force & Repetition– Force & Posture
VibrationHighly Repetitive Work
– Alone or in Combination with other factors– Cycle time of less than 30 seconds or more than 50% of
the cycle time involved in performing fundamentally the same activity
Cumulative Trauma DisorderCumulative Trauma Disorder Analyzing Occupational Risk FactorsAnalyzing Occupational Risk Factors
Forceful Work– 4 kg (but most jobs without effective technique to assess
actual grip force)
Awkward Postures– Posturing more than 45°
Keyboard Activities Cold Environment Length of Employment Tool Size & Weight
Cumulative Trauma DisorderCumulative Trauma DisorderContributory Factors in the Work PlaceContributory Factors in the Work Place
Psychomotor Skills (coordination)
– Not identified as a risk factor
Cumulative Trauma DisorderCumulative Trauma DisorderEvidenceEvidence
The scientist often uses literature as the drunk uses a light post
Cumulative Trauma DisorderCumulative Trauma DisorderEvidenceEvidence
The scientist often uses literature as the drunk uses a light post
More often for support than for illumination
Cumulative Trauma DisorderCumulative Trauma DisorderEvidenceEvidence
AMA Guides to the Evaluation of Disease & Injury Causation 2nd Edition
Melhorn, Ackerman, Talmage, Hyman
Cumulative Trauma DisorderCumulative Trauma Disorder Useful Research TermsUseful Research Terms
“Typical results are shown…”– The best results are shown
Cumulative Trauma DisorderCumulative Trauma DisorderDiseases Caused by ExposureDiseases Caused by Exposure
Vibration & White Finger SyndromeStress Fractures (esp. Metatarsals)Blisters, calluses
Cumulative Trauma DisorderCumulative Trauma Disorder Useful Research TermsUseful Research Terms
“It has long been known…”– I didn’t look up the original references
“Typing causes Carpal Tunnel Syndrome”
Cumulative Trauma DisorderCumulative Trauma DisorderCarpal Tunnel SyndromeCarpal Tunnel Syndrome
Risk Factor EvidenceCombination of Risk Factors Strong Risk Evidence
– Meat packing, poultry packing, automotive industry
Vibration Low Risk Evidence– But laboratory studies support this claim
Highly Repetitive Work Strong Risk Evidence– But must define repetition
Forceful Work Strong Risk EvidenceAwkward Postures Low Risk Evidence
Cumulative Trauma DisorderCumulative Trauma DisorderCarpal Tunnel SyndromeCarpal Tunnel Syndrome
Risk Factor EvidenceKeyboard Activities No Risk EvidenceCold Environment No Risk EvidenceLength of Employment No Risk EvidenceJob Satisfaction Some Risk Evidence
Cumulative Trauma DisorderCumulative Trauma DisorderCarpal Tunnel SyndromeCarpal Tunnel Syndrome
Risk Factor EvidenceAge: Very Strong Evidence
– Commonly Seen in 4th DecadeWeight: Very Strong Evidence
– Correlated (BMI > 30)Disease: Very Strong Evidence
Diabetes Rheumatoid Arthritis Hypothyroid ESRD
Gender: Very Strong Evidence– 3:1 Female to Male
Cumulative Trauma DisorderCumulative Trauma DisorderCarpal Tunnel SyndromeCarpal Tunnel Syndrome
Risk Factor EvidenceBiopsychosocial Factors: Very Strong EvidenceSmoking: Low Risk EvidenceWrist Size: Some Risk EvidenceNonoccupational Activities: Some Risk EvidenceHand Dominance: No Risk Evidence
– Consider this lack of correlation in light of arguments associating CTS with use. Further, since people awaken at night with symptoms, is sleep a cause?
Cumulative Trauma DisorderCumulative Trauma DisorderUseful Research TermsUseful Research Terms
“It is clear that much additional work will be required before a complete understanding of the phenomenon occurs..”
I don’t understand it
Cumulative Trauma DisorderCumulative Trauma DisorderCubital Tunnel SyndromeCubital Tunnel Syndrome
Risk Factor EvidenceAge: Strong Risk Evidence
– 6th decade, and increases with each decade of lifeWeight: Low Risk EvidenceDisease: Some Risk EvidenceGender: Some Risk EvidenceBiopsychosocial Factors:* No Risk EvidenceSmoking: Some Risk EvidenceHand Dominance: No Risk Evidence
Cumulative Trauma DisorderCumulative Trauma DisorderCubital Tunnel SyndromeCubital Tunnel Syndrome
Risk Factor EvidenceCombination of Risk Factors Some Risk EvidenceVibration No Risk EvidenceHighly Repetitive Work No Risk EvidenceForceful Work No Risk EvidenceAwkward Postures No Risk EvidenceKeyboard Activities No Risk EvidenceCold Environment No Risk EvidenceLength of Employment No Risk Evidence
Cumulative Trauma DisorderCumulative Trauma Disorder Useful Research TermsUseful Research Terms
“While it has not been possible to provide definitive answers to these questions…”
An unsuccessful experiment, but I still hope to get it published
Cumulative Trauma DisorderCumulative Trauma Disorderde Quervain’sde Quervain’s
Age: Strong EvidenceGender: Strong Evidence
– 5:1 Female ratio
Role of New mother’s disease
Cumulative Trauma DisorderCumulative Trauma Disorderde Quervainde Quervain
Risk Factor EvidenceCombination of Risk Factors Some Risk Evidence*Vibration No Risk EvidenceHighly Repetitive Work Some Risk Evidence*Forceful Work Some Risk EvidenceAwkward Postures Low Risk EvidenceKeyboard Activities Low Risk EvidenceCold Environment No Risk EvidenceLength of Employment No Risk Evidence
Cumulative Trauma DisorderCumulative Trauma Disorder Useful Research TermsUseful Research Terms
“Time and time again…”
I have seen it twice before
Cumulative Trauma DisorderCumulative Trauma DisorderTrigger FingerTrigger Finger
Age: Commonly Seen in 6th DecadeDisease: Increased Prevalence
Diabetes Hypothyroid
Gender: 4:1 Female to Male
Cumulative Trauma DisorderCumulative Trauma DisorderTrigger FingerTrigger Finger
Risk Factor EvidenceCombination of Risk Factors Some Risk EvidenceVibration Some Risk EvidenceHighly Repetitive Work Low Risk EvidenceForceful Work Low Risk EvidenceAwkward Postures Low Risk EvidenceKeyboard Activities No Risk EvidenceCold Environment No Risk EvidenceLength of Employment No Risk Evidence
Cumulative Trauma DisorderCumulative Trauma Disorder Useful Research TermsUseful Research Terms
“Three of the samples were chosen for detailed study…”
Since it didn’t work, maybe I can prove my point with selection bias and by eliminating any contrarian data
Cumulative Trauma DisorderCumulative Trauma DisorderTriangular Fibrocartilage Complex (TFCC)Triangular Fibrocartilage Complex (TFCC)
Risk Factor EvidenceCombination of Risk Factors No Risk EvidenceVibration No Risk EvidenceHighly Repetitive Work No Risk EvidenceForceful Work No Risk EvidenceAwkward Postures No Risk EvidenceKeyboard Activities No Risk EvidenceCold Environment No Risk EvidenceLength of Employment No Risk Evidence
Cumulative Trauma DisorderCumulative Trauma DisorderTriangular Fibrocartilage Complex (TFCC)Triangular Fibrocartilage Complex (TFCC)
Risk Factor EvidenceAge Strong Risk EvidenceAnatomy Strong Risk Evidence
Mechanism of Injury
– Traumatic vs Degenerative Twisting Palmar Rotation (i.e. fall)
– Ulnar Impaction
Cumulative Trauma DisorderCumulative Trauma Disorder Useful Research TermsUseful Research Terms
“A definite trend is evident…”– These data are practically meaningless
Cumulative Trauma DisorderCumulative Trauma DisorderLateral Epicondylitis (Tennis Elbow)Lateral Epicondylitis (Tennis Elbow)
Risk Factor EvidenceCombination of Risk Factors Strong Risk EvidenceVibration No Risk EvidenceHighly Repetitive Work No Risk EvidenceForceful Work Low Risk EvidenceAwkward Postures Low Risk EvidenceKeyboard Activities No Risk EvidenceCold Environment No Risk EvidenceLength of Employment No Risk Evidence
Cumulative Trauma DisorderCumulative Trauma DisorderLateral Epicondylitis (Tennis Elbow)Lateral Epicondylitis (Tennis Elbow)
Age: Commonly Seen in 4th Decade– Had it not been for the exposure, condition
would not have occurred
Repetition/ Lifting: CorrelatedBut consider vocational & avocational
activities
Cumulative Trauma DisorderCumulative Trauma Disorder Useful Research TermsUseful Research Terms
“It is clear that much additional work will be required before a complete understanding of the phenomenon occurs…”
I don’t understand any of it
Cumulative Trauma DisorderCumulative Trauma DisorderRotator CuffRotator Cuff
Age: Commonly Seen in 4th DecadeRepetition: Overhead lifting
Cumulative Trauma DisorderCumulative Trauma Disorder Useful Research TermsUseful Research Terms
“A careful analysis of available data…”
I lost three pages of information when I spill my beer
Cumulative Trauma DisorderCumulative Trauma DisorderCMC ArthritisCMC Arthritis
Risk Factor EvidenceAge: Very Strong Evidence
– Commonly Seen in 3rd-5thth DecadeWeight: Some EvidenceDisease: No EvidenceGender: Very Strong Evidence
– 4:1 Female to Male
– Peri- / post- menopausal correlation– 40% of all women
Hand Dominance No Evidence
Cumulative Trauma DisorderCumulative Trauma DisorderCMC ArthritisCMC Arthritis
Risk Factor EvidenceCombination of Risk Factors No Risk EvidenceVibration No Risk EvidenceHighly Repetitive Work No Risk EvidenceForceful Work No Risk EvidenceAwkward Postures Some Risk EvidenceKeyboard Activities No Risk EvidenceCold Environment No Risk EvidenceLength of Employment No Risk Evidence
Cumulative Trauma DisorderCumulative Trauma DisorderUseful Research TermsUseful Research Terms
“Correct within an order of magnitude…”
Wrong
Cumulative Trauma DisorderCumulative Trauma DisorderGanglionGanglion
Occupational Risk Factors: Insufficient evidence – Repetition: Causes cyst to enlarge, but no
evidence for causal link – Trauma: 5% of cyst
Age: Seen at any ageCommon process accounting for 50-70%
of finger/hand/wrist masses
Cumulative Trauma DisorderCumulative Trauma DisorderIndustrial vs. Occupational ExposuresIndustrial vs. Occupational Exposures
Cumulative Trauma DisorderCumulative Trauma DisorderCategorizationCategorization
Category 1: Diagnosis is easily established, good methods are available for treating the condition, and the prognosis for returning to work is good.
– Still, remember: Diagnosis does not equal etiology
Cumulative Trauma DisorderCumulative Trauma DisorderCategorizationCategorization
Category 2: Diagnosis is established, but neither nonsurgical nor surgical treatment is always successful in returning the patient to the original job.
– Injury may preclude the patient from being able to reestablish premorbid status
– Vocational Rehab– Job modification
Cumulative Trauma DisorderCumulative Trauma DisorderCategorizationCategorization
Category 3: The condition combines definite physical problems and additional non-medical issues.
– Factor 1: Chronic pain out of proportion to the disorder
– Factor 2: Manifestation of anger, frustration, and depression associated with the injury, as well as psychosocial or economic issues.
Cumulative Trauma DisorderCumulative Trauma DisorderCategorizationCategorization
Category 4: Diagnosis is unclear.
– Factor 1: Generalized, vague aching discomfort and no specific diagnosis can be made.
– Factor 2: Chronic fibromyalgia or other rheumatologic abnormalities.
– Factor 3: Repetitive strain injury.
Repetitive Strain Injury Repetitive Strain Injury History: Australia: PsychologyHistory: Australia: Psychology
Japanese cartoon triggers seizures in hundreds of children
December 17, 1997Web posted at: 4:15 a.m. EST (0915 GMT) TOKYO (CNN) -- The bright flashing lights of a popular TV cartoon became a serious matter Tuesday evening, when they triggered seizures in hundreds of Japanese children. In a national survey, the Tokyo fire department found that at least 618 children had suffered convulsions, vomiting, irritated eyes, and other symptoms after watching "Pokemon."
Cumulative Trauma DisorderCumulative Trauma DisorderDefinitions: DiagnosesDefinitions: Diagnoses
Shoulder-arm Syndrome
– Specific diagnosis—neuropathy of the brachial plexus.
– Diagnosis does not equal etiology
Cumulative Trauma DisorderCumulative Trauma DisorderEtiologic ClassificationsEtiologic Classifications
1. Pain caused by the work task
Rotator Cuff Tennis Elbow de Quervain’s
Note: These may be caused by work, but may also be pre-existing
Cumulative Trauma DisorderCumulative Trauma DisorderEtiologic ClassificationsEtiologic Classifications
1. Pain caused by the work task
2. Pain aggravated by but not caused by the work task
CMC Arthritis Post-Traumatic
Arthritis
Cumulative Trauma DisorderCumulative Trauma DisorderEtiologic ClassificationsEtiologic Classifications
1. Pain caused by the work task
2. Pain aggravated by but not caused by the work task.
3. Pain unrelated to the work task, but develops serendipiditously during work
Dupuytren’s Disease
Note: The contentious diagnosis of CTS may fall into group 1, 2, or 3.
Cumulative Trauma DisorderCumulative Trauma DisorderEtiologic ClassificationsEtiologic Classifications
1. Pain caused by the work task
2. Pain aggravated by but not caused by the work task.
3. Pain unrelated to the work task, but develops serendipiditously during work
4. Pain that is unrelated to the physical work task– Psychological stress – Patient’s personality
Cumulative Trauma DisorderCumulative Trauma DisorderEtiologic ClassificationsEtiologic Classifications
1. Pain caused by the work task
2. Pain aggravated by but not caused by the work task.
3. Pain unrelated to the work task, but develops serendipiditously during work
4. Pain that is unrelated to the physical work task
5. Pain that is unrelated to the work task in any way but is dishonestly attributed to it. – Didn’t happen at work – Factitious processes