Psychol. Inj. and Law
DOI 10.1007/s12207-009-9055-2
Perceived Injustice is Associated with Heightened
Pain Behavior and Disability in Individuals
with Whiplash Injuries
Michael J. L. Sullivan & Nicole Davidson &
Beatrice Garfinkel & Nathida Siriapaipant &
Whitney Scott
# Springer Science+Business Media, LLC 2009
Abstract The present study examined the relationship
between perceived injustice associated with whiplash injury
and displays of pain behavior. Individuals (N=85) with
whiplash injuries were filmed while performing a simulated
occupational lifting task. They were also asked to complete
measures of pain, perceived injustice, catastrophic thinking,
depression, and functional disability. Consistent with
previous research, high levels of perceived injustice were
associated with more intense pain, higher levels of
catastrophic thinking, depression, and disability. Analyses
revealed that individuals with high levels of perceived
injustice displayed more protective pain behaviors than
individuals with low levels of perceived injustice, regardless of the level of physical demand of the task. The
relation between perceived injustice and protective pain
behavior remained significant even when controlling for
pain severity, catastrophic thinking, and depression. There
was no significant association between perceived injustice
and displays of communicative pain behavior. The results
of this study suggest that the relation between perceived
injustice and pain behavior might underlie the high
This research was supported by grants from the Fonds de la recherche
en santé du Québec (FRSQ) and the Canadian Institutes of Health
Research (CIHR).
The authors have no financial interests related to the content of this
paper.
M. J. L. Sullivan (*) : N. Davidson : B. Garfinkel : W. Scott
Department of Psychology, McGill University,
1205 Docteur Penfield Ave,
Montréal, Québec H3A 1B1, Canada
e-mail: [email protected]
N. Siriapaipant
Department of Psychology, Concordia University,
Montreal, Canada
prevalence of occupational disability in individuals who
have sustained whiplash injuries. Implications for intervention are addressed.
Keywords Whiplash injury . Neck pain .
Perceived injustice . Pain behavior . Disability
Introduction
The post-injury life experience of individuals who have
sustained debilitating whiplash injuries might be one
characterized by significant losses. These might include
loss of function, loss of employment, loss of enjoyment,
loss of financial security, and in severe cases, loss of
independence (Gatchel et al. 2002; Wallin and Raak 2008).
If losses are perceived as undeserved, it is possible that
individuals will experience their life situation as unjust
(Lind and Tyler 1988).
Perceptions of injustice can arise under conditions where
someone suffers hardship or loss undeservedly (Hamilton
and Hagiwara 1992; Lind and Tyler 1988). Research has
shown that perceptions of injustice are likely to arise when
an individual is exposed to situations that are characterized
by a violation of basic human rights, transgression of status
or rank, or challenge to equity norms and just world beliefs
(Fetchenhauer and Huang 2004; Hafer and Begue 2005;
Mohiyeddini and Schmitt 1997). The experience of
unnecessary suffering as a result of another’s actions and
the experience of irreparable loss are also likely to give rise
to perceptions of injustice (Miller 2001). A case can be
made that the situations or conditions that contribute to a
sense of injustice characterize the life situation of the
individual who has sustained a whiplash injury.
Psychol. Inj. and Law
Surprisingly, the role of perceived injustice on reactions to
whiplash injury has not drawn significant research attention.
It appears that issues concerning perceptions of injustice
following injury have been relegated to the legal domain and
questions related to the psychological antecedents or
consequences of perceptions of injustice following whiplash
injury have remained largely unexplored. More than 10 years
ago, emotion researchers commented on the conspicuous
absence of research on the psychological consequences of
perceived injustice (Mikula et al. 1998).
Emerging research findings suggest that perceptions of
injustice consequent to musculoskeletal injury might
contribute to more severe disability (Sullivan et al. 2008).
For example, blame attributions related to injury have been
associated with heightened emotional distress (DeGood and
Kiernan 1996; Ferrari and Russell 2001). Perceptions of
injustice have been associated with more severe pain, the
persistence of post-traumatic stress symptoms, greater selfreported functional limitations, and lower probability of
returning to work (Sullivan et al. 2008, 2009). If legal
action for losses associated with whiplash injury is
construed as a proxy for perceived injustice, the literature
on adverse health outcomes of litigation also supports the
view that perceived injustice might impede successful
recovery from whiplash injury (Blyth et al. 2003; Ferrari
and Russell 2001).
Although research supports a relation between perceived
injustice and persistent disability, the process by which
perceptions of injustice impact on disability remains unclear.
One possibility is that perceptions of injustice might contribute
to heightened displays of pain behavior. Pain behavior refers to
movement alterations or expressive displays that are enacted
during the experience of pain. Pain behaviors can take varied
forms including activity avoidance, redistribution of weight to
alleviate pressure on affected limbs, holding or rubbing
affected areas of the body, facial grimaces, and vocalizations
(Hadjistavropoulos and Craig 2002). Research shows that
heightened expressions of pain behavior are associated with a
variety of adverse outcomes such as increased pain, depression, functional disability, and prolonged work absence
(Prkachin et al. 2002, 2007). Research has also shown that
psychological factors are more powerful predictors of pain
behavior than pain itself (Thibault et al. 2008).
There are both empirical and conceptual grounds for
positing a relation between perceptions of injustice and
expressions of pain behavior. For example, previous
research has shown that perceptions of injustice are
associated with increased pain and depression, and high
levels of pain catastrophizing (Sullivan et al. 2008).
Perceptions of injustice might impact on pain behavior
indirectly as a function of increased pain or depression. It
is also possible that a relation between perceptions of
injustice and pain behavior might simply reflect the
influence of pain catastrophizing on pain behavior
(Thibault et al. 2008).
From a conceptual perspective, it has been suggested
that perceptions of injustice are likely to give rise to
revenge motives (Orth et al. 2006). For the person who has
sustained a whiplash injury, there are few direct options for
revenge. In essence, convincing demonstrations of severity
of injury or extent of loss might represent the few potential
routes the victim of injustice can pursue to obtain some
form of retribution (Miller 2001). It could be argued that
pain behavior might be one of the few vehicles through
which whiplash victims can publicly communicate the
severity of their injury or the extent of their loss (Sullivan et
al. 2008).
In the present study, individuals who had sustained
whiplash injuries in rear collision motor vehicle accidents
were filmed while they performed a simulated occupational
lifting task, and video records were coded for the presence
of pain behaviors. It was hypothesized that high scores on a
measure of perceived injustice would be associated with
heightened display of pain behavior during the occupational
lifting task. Analyses also addressed the degree to which
the relation between perceived injustice and pain behavior
could be accounted for by pain severity, depression, and
pain catastrophizing. Exploring the relation between perceived injustice and pain behavior might have both
theoretical and clinical implications. From a theoretical
perspective, the results of this research might elucidate
some of the psychological mechanisms that contribute to
problematic health outcomes following whiplash injury.
From a clinical perspective, demonstrating a relation
between perceived injustice and pain behavior might
provide the empirical foundation for the development of
novel interventions that could promote more successful
recovery and rehabilitation following whiplash injury.
Methods
Participants
The study sample consisted of 85 individuals (45 women,
40 men) who had sustained whiplash injuries in rearcollision motor vehicle accidents (unrelated to employment). The mean age of the sample was 39.1 years with a
range of 20 to 59 years. The mean number of months since
injury was 18.2 with a range of 3 to 50 months. The
majority of participants (73%) had completed at least
12 years of education. The majority of the sample (81%)
was married or living common law.
At the time of testing, all participants were workdisabled and were receiving salary indemnity. In the
province of Quebec, Canada, all individuals are covered
Psychol. Inj. and Law
under a state-run no-fault insurance system (Société de
l'assurance automobile du Québec) that provides access to
required health services and salary indemnity in case of
work disability consequent to motor vehicle accidents.
Measures
Pain Severity
Participants were asked to complete the McGill Pain
Questionnaire (MPQ) (Melzack, 1975) to assess their
current pain severity. The Pain Rating Index (PRI) of the
MPQ is a weighted sum of all adjectives endorsed and is
considered a reliable and valid index of an individual’s
pain experience associated with whiplash (Turk et al.
1985; Veilleux et al. 1989). Participants were also asked to
rate the severity of their pain on an 11-point numerical
rating scale with the endpoints (0) no pain and (10)
excruciating pain.
Self-Rated Disability
The Pain Disability Index (PDI) (Pollard 1984) assesses
the degree to which respondents perceive themselves to be
disabled in seven different areas of daily living (home,
social, recreational, occupational, sexual, self-care, and
life support). For each life domain, respondents are asked
to provide perceived disability ratings on 11-point scales
with the endpoints (0) no disability and (10) total
disability. The PDI has been shown to be internally
reliable and significantly correlated with objective indices
of disability (Tait et al. 1987, 1990).
Catastrophizing
The Pain Catastrophizing Scale (PCS) (Sullivan et al. 1995)
was used as a measure of catastrophic thinking related to
pain. The PCS instructions ask participants to reflect on
past painful experiences and to indicate the degree to which
they experienced each of 13 thoughts or feelings when
experiencing pain, on five-point scales with the endpoints
(0) not at all and (4) all the time. The PCS has been shown
to have high internal consistency and to be associated with
heightened pain, disability, as well as employment status
(French et al. 2005; Sullivan and Stanish 2003).
Depression
The Beck Depression Inventory II (Beck et al. 1996) was
used as a self-report measure of depressive symptom
severity. The BDI-II consists of 21 statements describing
various symptoms of depression, and respondents choose
the statement that best describes how they have been
feeling over the past 2 weeks. Responses are summed to
yield an overall index of severity of depressive symptoms.
The BDI-II has been shown to be a reliable and valid index
of depressive symptoms in chronic pain patients and
primary care medical patients (Arnau et al. 2001; Harris
and D'Eon 2008).
Demographic Variables
Patients were asked to respond to questions concerning
their age, sex, marital status, education, occupation, and
medication use.
Perceived Injustice
Procedure
The Injustice Experiences Questionnaire (IEQ) was used to
assess perceptions of injustice (Sullivan et al. 2008). The
IEQ is a 12-item scale that asks respondents to indicate the
frequency with which they experience different thoughts
concerning the sense of unfairness in relation to their injury
on a 5-point scale with the endpoints (0) never and (4) all
the time. On this measure, perceived injustice is construed
as an appraisal cognition comprising elements of the
severity of loss consequent to injury (“Most people don’t
understand how severe my condition is”), blame (“I am
suffering because of someone else’s negligence”), a sense
of unfairness (“It all seems so unfair”), and irreparability of
loss (“My life will never be the same”). Previous research
suggests that the IEQ yields two correlated factors that have
been labeled severity/irreparability of loss and blame/
unfairness (Sullivan et al. 2008). The IEQ has been shown
to be internally reliable and to predict prolonged disability
following musculoskeletal injury (Sullivan et al. 2008).
The study sample was recruited through newspaper
advertisements and notices placed in rehabilitation clinics
in the Montreal, Quebec region. Individuals were considered for enrolment if they had sustained a whiplash injury
in a rear-collision motor vehicle accident at least three
months prior to enrolment. A diagnosis of Whiplash
Associated Disorders, Grades 1 or 2 was confirmed by
medical evaluation.
The research was approved by the ethics review
committee of the Centre de recherche interdisciplinaire en
réadaptation de Montréal métropolitain. Participants were
invited to sign a consent form as a condition of enrolment
in the study. Participants were asked to complete questionnaires assessing cognitive and affective variables related to
pain, distress, and disability.
Participants were informed that the study was
concerned with the development of a new assessment
Psychol. Inj. and Law
procedure for individuals suffering from persistent pain.
They were made aware that the lifting task might lead to
temporary increases in discomfort, and they were free to
discontinue at any point.
A lifting task modeled after Butler and Kozey (2003)
was used to elicit pain behaviors. Participants were asked to
stand in front of a table (adjusted to waist height; surface=
80×120 cm) on which were placed 18 containers (4-L size
paint canisters) that were partially filled with sand. The
canisters weighed 2.9, 3.4, or 3.9 kg and were arranged in
three rows of six canisters. The selection of loads was based
on research suggesting a 12% weight difference for
detection threshold and National Institute for Occupational
Safety and Health recommendations for safety weight limits
(Karwowski et al. 1992; Waters et al. 1993).
The different weight canisters were positioned such
that each weight was represented twice in each location
of a double latin square. Since different weights were
used, it was not possible for the participant to anticipate
the weight of the canisters at subsequent lifts. The task
was designed such that the forward flexion and arm
extension required to lift canisters further away from the
body would increase the loading on the cervical
portions of the spine, momentarily increasing discomfort
(Tsuang et al. 1992). The canister locations corresponded
to three functional anthropometric postural positions:
normal, maximum, and extreme reaches. In the normal
reach position (position 1), the participant stood erect with
his or her elbow bent at 90°; in the maximum reach
position (position 2), the participant stood erect with his or
her arm fully extended; in the extreme reach condition, the
participant was forward flexed with his or her arm fully
extended (Butler and Kozey 2003).
Participants were asked to lift canisters in a predetermined sequence (i.e., column 1, first, second, third position;
column 2, first, second, third position; etc). Participants
were then asked to provide a verbal rating of their pain as
they lifted each canister, on an 11-point scale with the
endpoints (0) no pain and (10) extreme pain. Three
composite pain ratings were obtained corresponding to the
three different postural positions.
Pain Behavior
Participants were videotaped throughout the procedure.
One camera was positioned at a 45° angle to the table and
provided a 3/4 view of the face, trunk, and upper
extremities of the participant. A second camera positioned
directly in front of the participant provided a close-up of the
face. Participants’ verbal pain ratings after each lift were
audio-taped. Participants were aware that they were being
videotaped.
Two trained coders, blind to experimental hypotheses,
independently coded each video record for instances of pain
behavior. The procedure used for assessing pain behavior
was modeled after the coding system originally developed
by Keefe and Block (1982) and modified for use with the
lifting task. The pain coding system has been used in
several studies and described in more detail in Thibault et
al. (2008) and Sullivan et al. (2006). Coders were trained to
competency using a pain behavior-coding manual developed for the present study.
Each video record was divided into 18 different segments (i.e., cycles) corresponding to the lift of each
different canister. A cycle was defined as the period starting
with the participant touching the handle of one canister and
ending with the moment the participant touched the handle
of the next canister. For each cycle, the duration of pain
behaviors was recorded. Pain behaviors were classified as
communicative pain behaviors or protective pain behaviors.
Communicative pain behaviors included: (1) facial expressions such as grimacing or wincing and (2) verbal or
paraverbal pain expressions such as pain words, grunts,
sighs, and moans. Protective pain behaviors included
guarding, holding, touching, or rubbing.
Percentage agreement for the classification of different
pain behaviors relative to the total number of different pain
behaviors coded was computed for each category of pain
behavior. Average agreement for communicative and
protective pain behaviors was 87.3% and 84.6%, respectively. Discrepancies were resolved through discussion.
Indices of pain behavior were computed separately for
communicative and protective pain behaviors by summing
the duration of pain behavior for each category (Prkachin et
al. 2004).
Data Analytic Approach
Means and standard deviations were computed for demographic and dependent measures. Separate t tests for
independent samples were used to examine sex differences
on demographic and dependent measures. Pearson correlations (r) were performed to examine the relation between
perceived injustice, pain, and pain-related psychological
variables.
The pain ratings and pain behavior data were analyzed as
a three-way mixed factorial with canister position (pos 1,
pos 2, pos 3) as a within groups factor and sex (male,
female) and level of perceived injustice (high, low; based
on median split) as the between groups factors. Canister
position was used as a manipulation of physical demands.
Analyses of covariance were used to examine whether
effects due to perceived injustice could be accounted for by
catastrophizing or depression. Finally, a direct regression
Psychol. Inj. and Law
analysis was conducted to examine whether pain behavior
mediated the relation between perceived injustice and selfreported disability.
loskeletal injuries (Adams et al. 2008; Sullivan et al. 2008).
There were no significant sex differences on perceptions of
injustice, tIEQ (83)=0.74, ns.
Correlations among Pain-Related Variables
Results
Sample Characteristics
Means and standard deviations on demographic and
dependent variables are presented in Table 1. Mean scores
on measures of pain severity, self-reported disability,
perceived injustice, pain catastrophizing, and depression
are comparable to those reported in previous studies
addressing the psychological determinants of pain and
disability associated with whiplash injuries (Sterling et al.
2003, 2005; Sullivan et al. 2008).
In this sample, there were no significant sex differences for
age, t (83)=−0.14, ns, years of education, t (83)=0.09, ns, or
months since injury, t (83)=−0.91, ns. Women (M=37.5,
SD=12.5) rated their pain as more intense than men (M=
27.2, SD=11.1), tMPQ (83)=4.0, p<0.001, women (M=34.0,
SD=11.3) obtained higher catastrophizing scores than men
(M=25.4, SD=9.0), tPCS (83)=3.8, p<0.001, women (M=
24.7, SD=12.2) obtained higher depression scores than men
(M=13.2, SD=9.0), tBDI (83)=4.7, p<0.001, and women
rated their disability as more severe (M=36.0, SD=16.6)
than men (M=27.1, SD=13.2), tPDI (83)=2.6, p<0.01. The
pattern of sex differences is consistent with results of
previous studies on individuals who have sustained muscu-
Table 1 Means and standard deviations on demographic and painrelated variables
Women
(n=45)
Men
(n=40)
p Value
Age
Duration (months)
Education (years)
MPQ PRI
MPQ PPI (0–10)
38.9
16.8
12.3
37.5
5.3
(11.1)
(12.8)
(1.6)
(12.5)
(2.3)
39.2
19.6
12.3
27.2
5.1
(8.0)
(15.2)
(1.6)
(11.1)
(2.0)
ns
ns
ns
.001
ns
IEQ
PCS
BDI-II
PDI
26.0
34.0
24.7
36.0
(11.1)
(11.3)
(12.2)
(16.6)
24.3
25.4
13.2
27.1
(10.6)
(9.0)
(9.0)
(13.2)
ns
.001
.001
.01
Values in parentheses are standard deviations. Significance tests were
two-tailed t tests
Duration time since injury; MPQ–PRI McGill Pain Questionnaire–
Pain-Rating Index; MPQ–PPI McGill Pain Questionnaire–Present
Pain Intensity; IEQ Injustice Experiences Questionnaire; PCS Pain
Catastrophizing Scale; BDI-II Beck Depression Inventory II; PDI Pain
Disability Index
Consistent with previous research, scores on the IEQ were
significantly correlated with indices of pain severity (MPQ–
PRI), self-reported disability (PDI), depression, and catastrophizing (Sullivan et al. 2008; see Table 2). Also consistent
with previous research, pain catastrophizing (PCS), depression (BDI-II), and perceived injustice (IEQ) were significantly correlated with indices of pain severity (Borsbo et al.
2008; Sullivan et al. 2008; Williamson et al. 2008).
Pain Ratings during the Lifting Task
A three-way (level of perceived injustice × sex × canister
position) mixed analysis (ANOVA) was conducted on pain
rating provided during the canister-lifting task. For this
analysis, perceived injustice was dichotomized as high or
low, based on a median split of IEQ scores (IEQ median=
23). Means and standard deviations for this analysis are
presented in Table 3.
A significant main effect for canister position was
obtained where pain ratings increased as a function of
increasing distance from the body, F (2, 162)=107.6,
p<.001. A significant Canister position × Sex interaction
was also obtained, F (1, 162)=9.7, p<.001. Test of simple
effects revealed that women (M=6.2, SD=2.4) rated their
pain as more intense than men (M=5.1, SD=2.0) but only
for canisters in position 3, t (83)=2.3, p<.05. No significant
effects involving level of perceived injustice were found.
Pain Behavior during the Lifting Task
Separate three-way (level of injustice × sex × canister
position) ANOVAs were performed on communicative
and protective pain behavior scores (see Fig. 1). For
communicative pain behaviors, significant main effects
emerged for canister position, F (2, 162)=21.3, p<.001,
and sex, F (1, 81)=4.3, p<.01, qualified by a significant
canister position × sex interaction, F (2, 162)=3.2, p<.05.
Tests of simple effects revealed that women displayed
communicative pain behaviors (M=15.1, SD=15.0) for
significantly longer duration than men (M=7.8, SD=10.6)
but only when lifting canisters in position 3, t(83)=2.5,
p<.01. There were no significant effects involving level of
perceived injustice.
For protective pain behaviors, main effects were
obtained for canister position, F (2, 162)=17.0, p<.001,
and level of perceived injustice, F (1, 81)=8.7, p<.01,
qualified by a significant canister position × level of
Psychol. Inj. and Law
Table 2 Correlations among measures
1
2
3
4
5
6
7
Age
Educ
Duration
IEQ
PCS
BDI-II
MPQ–PRI
PDI
0.02
−0.04
0.07
−0.01
0.01
0.17
0.02
−0.14
0.07
0.05
0.01
0.01
−0.01
0.06
0.15
−0.04
−0.05
0.07
0.45**
0.24*
0.31**
0.43**
0.61**
0.47**
0.42**
0.44**
0.25*
0.31**
9. CommBeh
10. ProtBeh
−0.04
0.05
−0.06
0.03
0.11
−0.12
0.07
0.34**
0.28**
0.25*
0.16
0.20
0.21*
0.19
1.
2.
3.
4.
5.
6.
7.
8.
8
9
0.22*
0.33*
0.23*
Educ years of education; Duration time (in months) since injury; IEQ Injustice Experiences Questionnaire; PCS Pain Catastrophizing Scale; BDIII Beck Depression Inventory II; MPQ–PRI McGill Pain Questionnaire–Pain Rating Index; PDI Pain Disability Index; CommBeh Communicative
Pain Behaviour Index; ProtBeh Protective Pain Behavior Index
*p<0.05; **p<0.01
perceived injustice interaction, F (2, 162)=3.5, p<.05. As
shown in Fig. 1b, participants with high levels of perceived
injustice displayed protective pain behaviors for longer
duration than participants with low levels of perceived
injustice at all three canister positions. Participants with
either high or low perceived injustice showed significant
increases in protective pain behavior as a function of
canister position; however, the effect of canister position
was more pronounced for participants with high levels of
perceived injustice, t(83)=2.0, p<.05.
Analyses of covariance were conducted to examine
whether the main effect for level of perceived injustice on
protective pain behaviors could be accounted for by pain
severity, catastrophizing, or depression. The results of these
analyses revealed that the main effect for perceived
injustice remained significant when controlling for scores
on the MPQ–PRI, F (1. 82)=6.7, p<.01, pain ratings during
the lifting task, F (1, 82)=8.3, p<.01, the PCS, F (1, 82)=
5.2, p<.05, and the BDI-II, F (1, 82)=6.7, p<.01.
Two hierarchical regression analyses were conducted to
examine whether pain behavior mediated the relation
between perceived injustice and disability (see Table 4).
In the first regression analysis, the PDI was used as the
dependent variable and the IEQ (as a continuous measure)
was used as the independent variable. The results of the
analysis revealed that the IEQ was a significant predictor of
Table 3 Pain ratings as a function of perceived injustice, sex, and
canister position
Low IEQ
Women
Men
High IEQ
Women
Men
Pos 1
Pos 2
Pos 3
2.9 (2.7)
3.8 (2.6)
4.2 (2.8)
4.5 (2.4)
5.6 (2.7)
5.4 (2.2)
4.3 (2.7)
3.6 (2.2)
5.5 (2.5)
4.1 (2.0)
6.6 (2.1)
4.7 (1.8)
Pain ratings were made on a 0 to 10 scale and averaged across three
lifts for each position
IEQ Injustice Experiences Questionnaire, Pos 1 position 1, Pos 2
position 2, Pos 3 position 3
Fig. 1 Communicative and protective pain behavior as a function of
perceived injustice and position. a Communicative Pain Behavior; b
Protective Pain Behavior
Psychol. Inj. and Law
Table 4 Regression analyses examining the relation between
perceived injustice and pain outcomes
β
Rchange2
Regression 1: Dependent = PDI
Step 1
IEQ
0.43**
0.20
Regression 2: Dependent = PDI
Step 1
ProtBeh
0.20*
0.11
Step 2
IEQ
0.36**
0.12
Fchange
p Value
21.9 (1, 83)
0.001
9.8 (1, 83)
0.01
12.0 (1, 82)
0.001
Beta weights in regression 2 are from the final regression equation
ProtBeh Protective Pain Behavior Index
self-reported disability (β=.43). In the second regression
analysis, a composite score of protective pain behavior
(averaged across the three canister positions) was entered in
the first step of the analysis, and the PDI was entered in the
second step. Of interest was whether the beta weight for the
PDI would be reduced when controlling for pain behavior.
The results of the analysis revealed that the inclusion of
protective pain behavior in the regression equation led to a
reduction in the magnitude of beta weight for the IEQ
(β=.36). Protective pain behavior partially mediated the
relation between perceived injustice and self-reported
disability (Sobel’s test=1.9, p<.05). However, in the final
regression equation, protective pain behavior and perceived
injustice each made significant unique contributions to the
prediction of self-reported disability.
Discussion
This study examined the relation between perceptions of
injustice and displays of pain behavior during the performance of a physically demanding task. The results of the
study are consistent with previous research showing that
perceptions of injustice are associated with heightened pain
and higher scores on measures of pain catastrophizing and
depression (Sullivan et al. 2008, 2009). The results of the
present study extend previous research in showing that
perceived injustice is associated with heightened displays of
protective pain behavior.
Perceived injustice was associated with heightened
levels of protective pain behavior but was unrelated to
communicative pain behavior. The relation between perceived injustice and protective pain behavior remained
significant even when controlling for variables known to be
associated with pain behavior such as pain severity, pain
catastrophizing, and depression. Mediational analyses
revealed that protective pain behavior might be one of the
processes through which perceived injustice might impact
on disability.
The pattern of findings provides further support for a
functional distinction between communicative and protective pain behaviors (Sullivan 2008). The findings are also
consistent with previous research showing that protective
pain behaviors are more strongly associated with disability
than communicative pain behaviors (Prkachin et al. 2007;
Sullivan et al. 2006). Pain behavior is one of the primary
means by which observers infer someone’s pain experience
(Hadjistavropoulos and Craig 2002; Prkachin and Craig
1995). The observation of heightened levels of pain
behavior in an injured patient might lead physicians to
infer high levels of pain and in turn, consider prescribing an
extended period of sick leave. The observation of heightened levels of pain behavior might also lead an employer to
consider that the employee is unable to meet his or her
occupational responsibilities. Communicative pain behaviors (e.g., facial displays, vocalizations) provide an effective
vehicle for the communication of suffering, but they do not
directly interfere with task performance. In addition to the
communication value of protective pain behaviors (e.g.,
overt display of distress), which might impact indirectly on
disability by influencing observers’ judgments of an
individuals’ potential limitations, protective pain behaviors
also engage the musculature that would be required for task
performance.
Distinguishing characteristics of communicative and
protective pain behaviors might provide insights into the
mechanisms by which perceived injustice might impact on
protective pain behavior (Sullivan 2008). Communicative
pain behaviors, at least facial displays, have been discussed
in terms of their automaticity (Williams 2002). In the
present study, removing verbal pain expressions from the
computation of the communicative pain behavior index
does not alter the pattern of findings. Facial displays of pain
behavior show consistency across the lifespan and across
cultures (Sullivan 2008; Williams 2002). Since facial
displays of pain are evident even in neonates, the
assumption has been that the motor programs that produce
facial pain expressions are inherited and present at birth
(Grunau and Craig 1987).
Protective pain behaviors are considered to function as a
means of reducing the probability of further injury or
reducing the intensity of pain (Sullivan 2008). Although the
primary function of protective pain behavior has been
discussed in terms of minimization of injury or pain, since
protective pain behaviors are also observable, they too have
communication value (Martel et al. 2008). Compared to
communicative pain behaviors, protective pain behaviors
(e.g., guarding, holding) have been discussed as intentional
(Sullivan 2008). In this context, however, intentional does
not necessarily imply conscious intention. To date, research
Psychol. Inj. and Law
has yet to elucidate the means by which degree of
conscious intent in the production of pain behavior can be
discerned with certainty.
It has been suggested that revenge motives might be
elicited by perceptions of injustice (Orth et al. 2006).
Perceived injustice might focus attention on issues related
to revenge and retribution and in turn fuel anger reactions
(Mikula et al. 1998). Under some circumstances, it is
possible that “disability” might represent the only “power”
that an individual possesses in efforts to bring about
retribution for losses sustained. In some cases, disability
behavior might be intentionally maintained in order to seek
adequate retribution for losses. Pain behavior might provide
a useful vehicle for publicly demonstrating the severity of
one’s disability. Challenges for future research will include
the development of paradigms that might elucidate the
motives underlying the expression of different forms of
pain behavior and the degree to which these motives are
consciously represented.
Regardless of the specific processes by which perceived injustice might impact on disability, the results of
recent research suggest that perceptions of injustice might
be an important target of intervention for individuals
recovering from whiplash injury. The impact that blame
cognitions have on feelings of anger and revenge motives
suggests that interventions to alter the injured individual’s
perceptions of the offender might be useful. Forgiveness
interventions have been described as potentially useful for
accident or crime victims (Wade and Worthington 2005).
Essentially, forgiveness is a method of dealing with an
offence or injustice that benefits victims through the
reorientation of their thoughts, emotions and behaviors
towards the offender (McCullough 2000; Wade and
Worthington 2005). Reducing perceptions of blame and
revenge might serve to decrease an individual’s attentional
focus on his or her pain and disability, which may have
previously been seen as the only means to ensure adequate
retribution for one’s suffering (Sullivan et al. 2008). One
issue surrounding forgiveness interventions, however, is
that the continuation of suffering, as is likely to occur for
victims of physical injury who have developed chronic
pain, might serve to impede the forgiveness process
(Baumeister et al. 1998).
Anger management interventions might also be of
benefit for individuals with high levels of perceived
injustice (Bruehl et al. 2003, 2006; Kerns et al. 1994).
While techniques targeting anger might help address
injustice perceptions of blame and unfairness, other
interventions might be needed to address cognitions of
severity and irreparability. The growing literature detailing
the benefits of pain acceptance on pain-related outcomes is
suggestive of one such intervention (McCracken and
Eccleston 2003, 2005; Vowles et al. 2007). Essentially,
acceptance entails continuing to pursue life goals and
valued activities even when pain is experienced and the
cessation of efforts to control or avoid pain (Vowles et al.
2007) and has been shown to decrease pain, disability, and
depression, as well as to improve individuals’ work status
(McCracken and Eccleston 2005). Based on the supposition
that the severity/irreparability and unfairness facets of
injustice perceptions are inherently linked (Sullivan et al.
2008), acceptance-based treatments aimed at reducing
severity cognitions may also help to reduce perceptions of
unfairness.
Some degree of caution is warranted in the interpretation
of the current findings. First, pain behavior was elicited in
an experimental context that might bear little resemblance
to the real world situations that typically give rise to pain
behavior. It is also important to consider that the “no fault”
system under which whiplash injuries are treated and
compensated in Quebec might influence individuals’
perceptions of injustice. Furthermore, although revenge
motives have been discussed as central to the experience of
injustice, and might underlie the expression of pain
behavior, revenge motives were not directly assessed in
the present study. In addition, other possible mediators of
the relation between perceived injustice and pain behaviors
such as anxiety sensitivity, fear of movement, secondary
gain, or certain personality dimensions were not assessed.
Finally, it is important to note that the intervention paths
that were briefly discussed have never been examined in the
context of individuals who have sustained whiplash
injuries.
In spite of these limitations, the present research suggests
that perceptions of injustice might represent a significant
determinant of expressions of pain behavior and disability
in individuals who have sustained whiplash injuries.
Questions for future research include the exploration of
the motives that might underlie the expression of pain
behavior in these individuals. Finally, interventions specifically targeting perceptions of injustice, blame attributions
and revenge motives might be needed in order to facilitate
recovery from whiplash injury.
References
Arnau, R. C., Meagher, M. W., Norris, M. P., & Bramson, R. (2001).
Psychometric evaluation of the Beck Depression Inventory-II
with primary care medical patients. Health Psychology, 20(2),
112–119.
Baumeister, R. F., Exline, J. J., & Sommer, K. L. (1998). The victim
role, grudge theory, and two dimensions of forgiveness. New
York: Templeton.
Beck, A., Steer, R., & Brown, G. K. (1996). Manual for the Beck
Depression Inventory - II. San Antonio: Psychological Corporation.
Blyth, F. M., March, L. M., Nicholas, M. K., & Cousins, M. J. (2003).
Chronic pain, work performance and litigation. Pain, 103, 41–47.
Psychol. Inj. and Law
Borsbo, B., Peolsson, M., & Gerdle, B. (2008). Catastrophizing,
depression, and pain: correlation with and influence on quality of
life and health - a study of chronic whiplash-associated disorders.
Journal of Rehabilitation Medicine, 40(7), 562–569.
Bruehl, S., Chung, O. Y., & Burns, J. W. (2003). Differential effects of
expressive anger regulation on chronic pain intensity in CRPS
and non-CRPS limb pain patients. Pain, 104(3), 647–654.
Bruehl, S., Chung, O. Y., & Burns, J. W. (2006). Anger expression
and pain: an overview of findings and possible mechanisms.
Journal of Behavioral Medicine, 29(6), 593–606.
Butler, H., & Kozey, J. (2003). The effect of load and posture on the
relative and absolute load estimates during simulated manual
material handling tasks in female checkout operators. International Journal of Industrial Ergonomics, 31, 331–341.
DeGood, D. E., & Kiernan, B. (1996). Perception of fault in patients
with chronic pain. Pain, 64, 153–159.
Ferrari, R., & Russell, A. (2001). Why blame is a factor in recovery
from whiplash injury. Medical Hypotheses, 56, 372–375.
Fetchenhauer, D., & Huang, X. (2004). Justice sensitivity and
distributive decisions in experimental games. Personality and
Individual Differences, 36, 1015–1029.
French, D., Noel, M., Vigneau, F., French, J., Cyr, C., & Evans, R.
(2005). L'Echelle de dramatisation face a la douleur PCS-CF:
Adaptation canadienne en langue francaise de l'echelle "Pain
Catastrophizing Scale". Revue canadienne des sciences du
comportement, 37(3), 181–192.
Gatchel, R., Adams, L., Polatin, P. B., & Kishino, N. (2002).
Secondary loss and pain-associated disability: theoretical overview and treatment implications. Journal of Occupational
Rehabilitation, 12, 99–110.
Grunau, R. V. E., & Craig, K. D. (1987). Pain expression in neonates:
facial action and cry. Pain, 28, 395–410.
Hadjistavropoulos, T., & Craig, K. (2002). A theoretical framework
for understanding self-report and observational measures of pain:
a communication model. Behaviour Research and Therapy, 40,
551–570.
Hafer, C. L., & Begue, L. (2005). Experimental research on just-world
theory: problems, developments and future challenges. Psychological Bulletin, 131, 128–167.
Hamilton, V. L., & Hagiwara, S. (1992). Roles, responsibility and
accounts across cultures. International Journal of Psychology,
27, 157–179.
Harris, C. A., & D'Eon, J. L. (2008). Psychometric properties of the
Beck Depression Inventory–second edition (BDI-II) in individuals
with chronic pain. Pain, 137(3), 609–622.
Karwowski, W., Shumate, C., Yates, J., & Pongpatana, N. (1992).
Discriminability of load heaviness: implications for the psychophysical approach to manual lifting. Ergonomics, 35, 729–744.
Keefe, F., & Block, A. (1982). Development of an observational
method for assessing pain behavior in chronic pain patients.
Behavior Therapy, 13, 363–375.
Kerns, R. D., Rosenberg, R., & Jacob, M. C. (1994). Anger expression
and chronic pain. Journal of Behavioral Medicine, 17(1), 57–67.
Lind, E. A., & Tyler, T. R. (1988). The social psychology of
procedural justice. New York: Plenum.
Martel, M. O., Thibault, P., Roy, C., Catchlove, R., & Sullivan, M. J.
(2008). Contextual determinants of pain judgments. Pain, 139(3),
562–568.
McCracken, L. M., & Eccleston, C. (2003). Coping or acceptance:
what to do about chronic pain? Pain, 105, 197–204.
McCracken, L. M., & Eccleston, C. (2005). A prospective study of
acceptance of pain and patient functioning with chronic pain.
Pain, 118(1–2), 164–169.
McCullough, M. E. (2000). Forgiveness as human strength: theory,
measurement, and links to well-being. Journal of Social and
Clinical Psychology, 19, 43–55.
Melzack, R. (1975). The McGill Pain Questionnaire: major properties
and scoring methods. Pain, 1, 277–299.
Mikula, G., Scherer, K. R., & Athenstaedt, U. (1998). The role of
injustice in the elicitation of differential emotional reactions.
Personality and Social Psychology Bulletin, 24, 769–783.
Miller, D. T. (2001). Disrespect and the experience of injustice.
Annual Review of Psychology, 52, 527–553.
Mohiyeddini, C., & Schmitt, M. J. (1997). Sensitivity to befallen
injustice and reactions to unfair treatment in a laboratory
situation. Social Justice Research, 10, 333–353.
Orth, U., Montada, L., & Maercker, A. (2006). Feelings of revenge,
retaliation motive, and post-traumatic stress reactions in crime
victims. Journal of Interpersonal Violence, 21, 229–243.
Pollard, C. A. (1984). Preliminary validity study of the Pain Disability
Index. Perceptual and Motor Skills, 59(3), 974.
Prkachin, K., & Craig, K. (1995). Expressing pain: the communication
and interpretation of pain signals. Journal of Nonverbal
Behavior, 19, 191–205.
Prkachin, K., Schultz, I., Berkowitz, J., Hughes, E., & Hunt, D.
(2002). Assessing pain behavior of low back pain patients in real
time: concurrent validity and examiner sensitivity. Behaviour
Research and Therapy, 40, 595–607.
Prkachin, K. M., Mass, H., & Mercer, S. R. (2004). Effects of
exposure on perception of pain expression. Pain, 111(1–2), 8–12.
Prkachin, K. M., Schultz, I. Z., & Hughes, E. (2007). Pain behavior
and the development of pain-related disability: the importance of
guarding. Clinical Journal of Pain, 23(3), 270–277.
Sterling, M., Kenardy, J., Jull, G., & Vicenzino, B. (2003). The
development of psychological changes following whiplash
injury. Pain, 106(3), 481–489.
Sterling, M., Jull, G., Vicenzino, B., Kenardy, J., & Darnell, R.
(2005). Physical and psychological factors predict outcome
following whiplash injury. Pain, 114, 141–148.
Sullivan, M. J. L. (2008). Toward a biopsychomotor conceptualisation
of pain. Clinical Journal of Pain, 24, 281–290.
Sullivan, M. J. L., & Stanish, W. D. (2003). Psychologically based
occupational rehabilitation: the pain-disability prevention program. Clinical Journal of Pain, 19(2), 97–104.
Sullivan, M. J. L., Bishop, S., & Pivik, J. (1995). The pain
catastrophizing scale: development and validation. Psychological
Assessment, 7, 524–532.
Sullivan, M. J. L., Thibault, P., Savard, A., Catchlove, R., Kozey, J., &
Stanish, W. D. (2006). The influence of communication goals
and physical demands on different dimensions of pain behavior.
Pain, 125(3), 270–277.
Sullivan, M. J. L., Adams, A., Horan, S., Mahar, D., Boland, D., &
Gross, R. (2008). The role of perceived injustice in the
experience of chronic pain and disability: scale development
and validation. Journal of Occupational Rehabilitation, 18, 249–
261.
Sullivan, M. J. L., Thibault, P., Simmonds, M. J., Milioto, M., Cantin,
A. P., & Velly, A. M. (2009). Pain, perceived injustice and the
persistence of post-traumatic stress symptoms during the course
of rehabilitation for whiplash injuries. Pain, 145(3), 325–331.
Tait, R. C., Pollard, C. A., Margolis, R. B., Duckro, P. N., & Krause,
S. J. (1987). The Pain Disability Index: psychometric and validity
data. Archives of Physical Medicine and Rehabilitation, 68(7),
438–441.
Tait, R. C., Chibnall, J. T., & Krause, S. (1990). The Pain Disability
Index: psychometric properties. Pain, 40(2), 171–182.
Thibault, P., Loisel, P., Durand, M. J., & Sullivan, M. J. L. (2008).
Psychological predictors of pain expression and activity intolerance in chronic pain patients. Pain, 139, 47–54.
Tsuang, Y., Schipplein, O., Trafimow, J., & Andersson, G. (1992).
Influence of body segment dynamics on loads at the lumbar spine
during lifting. Ergonomics, 35, 437–444.
Psychol. Inj. and Law
Turk, D. C., Rudy, T., & Salovey, P. (1985). The McGill Pain
Questionnaire: confirming the factor analysis and examining
appropriate uses. Pain, 21, 385–397.
Veilleux, S., Sicard, D., & Bohuon, A. (1989). Traduction de
McGill Pain Questionnaire. In R. Melzack & P. Wall (Eds.),
Le defi de la douleur. (Troisieme edition). St-Hyacinthe:
Edisem.
Vowles, K. E., McCracken, L. M., & Eccleston, C. (2007). Processes
of change in treatment for chronic pain: the contributions of pain,
acceptance, and catastrophizing. European Journal of Pain, 11
(7), 779–787.
Wade, N. G., & Worthington, E. L. (2005). In search of a
common core: a content analysis of interventions to promote
forgiveness. Psychotherapy: Theory, Research, Practice, Training, 42, 160–177.
Wallin, M. K., & Raak, R. I. (2008). Quality of life in subgroups of
individuals with whiplash-associated disorders. European Journal
of Pain, 12(7), 842–849.
Waters, T., Putz-Anderson, V., Garg, A., & Fine, L. (1993). Revised
NIOSH equation for the design and evaluation of manual lifting
tasks. Ergonomics, 36, 749–776.
Williams, A. (2002). Facial expression of pain: an evolutionary
account. Behavioral and Brain Sciences, 25, 439–488.
Williamson, E., Williams, M., Gates, S., & Lamb, S. E. (2008). A
systematic literature review of psychological factors and the
development of late whiplash syndrome. Pain, 135(1–2), 20–30.