Pain-Related Fear Contributes to Self-Reported Disability in Patients With Foot and Ankle Pathology

Transcription

1 557 ORIGINAL ARTICLE Pain-Related Fear Contributes to Self-Reported Disability in Patients With Foot and Ankle Pathology Trevor A. Lentz, PT, Zach Sutton, PT, DPT, Scott Greenberg, PT, DPT, Mark D. Bishop, PT, PhD ABSTRACT. Lentz TA, Sutton Z, Greenberg S, Bishop MD. Pain-related fear contributes to self-reported disability in patients with foot and ankle pathology. Arch Phys Med Rehabil 2010;91: Objective: To determine the unique influence of pain-related fear of movement on foot and ankle disability, after accounting for pain, demographic, and physical impairment variables. Design: Cross-sectional study using retrospective chart review. Setting: Outpatient rehabilitation clinic. Participants: Referred sample of subjects with foot- and ankle-related disability (N 85, 40 men; mean age, 33y; range, 16 77y). Interventions: Not applicable. Main Outcome Measures: Lower Extremity Functional Scale (LEFS), Shortened Tampa Scale of Kinesiophobia (TSK-11). Results: Hierarchical regression analysis determined the proportions of explained variance in disability (LEFS). Demographic variables were entered into the model first, followed by pain intensity and range-of-motion (ROM) deficit, and finally, TSK-11. Demographics collectively contributed 9% (P.015) of the variance in disability scores. Pain intensity and overall ROM deficit contributed an additional 11% (P.001) of the variance, and TSK-11 scores contributed an additional 14% (P.001). In the overall model, age (.29, P.004), chronicity of symptoms (.23, P.024), ROM deficit (.28, P.003), and TSK-11 (.41, P.001) explained 34% of the variance in the LEFS score (P.001). Conclusions: Age, chronicity of symptoms, ROM deficit, and TSK-11 scores all significantly contributed to baseline foot and ankle self-reported disability. Pain-related fear of movement was the strongest single contributor to disability in this group of patients. Key Words: Ankle; Fear; Foot; Psychology; Rehabilitation by the American Congress of Rehabilitation Medicine THE FOOT AND ANKLE are common sources of pain and disability, with approximately 2 million people in the United States per year affected by foot pain. 1 As many as 25% of sports injuries have been attributed to the foot or ankle, 2 with ankle sprains accounting for up to 45% of all injuries in some sports. Outcomes of conservative treatment range widely From Shands Rehabilitation, UF & Shands Orthopaedics and Sports Medicine Institute (Lentz, Greenberg), Shands Rehabilitation, Magnolia Parke (Sutton), Gainesville, FL; and Department of Physical Therapy, University of Florida (Bishop), Gainesville, FL. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated. Correspondence to Trevor A. Lentz, PT, Shands Rehabilitation, UF & Shands Orthopaedics and Sports Medicine Institute, PO Box , Gainesville, FL 32611, lentzt@shands.ufl.edu. Reprints are not available from the author /10/ $36.00/0 doi: /j.apmr among diagnoses, with as many as 74% of patients with ankle sprains experiencing symptoms up to 4 years after injury. 3 Many athletes do not return to their prior level of sports participation after ankle injury. Factors affecting the development of foot and ankle disability include age, 4 pain, 5 ROM, 1,6 BMI, 7 and occupations requiring prolonged standing. 1 The influence of psychologic variables, however, as mediators of pain and disability in foot- and ankle-related pathologies has not been examined extensively in the rehabilitation literature. One such psychologic variable of particular interest in our current study, pain-related fear of movement, or kinesiophobia, has been shown to contribute to disability in a variety of musculoskeletal conditions involving the spine, 8-10 knee, and shoulder, but has not yet been studied in the foot and ankle population. Kinesiophobia has been described as an excessive, irrational, and debilitating fear of physical movement and activity resulting from a feeling of vulnerability to painful injury or reinjury. 17 The FAM of musculoskeletal pain has been proposed to describe the interaction by which psychologic characteristics, including pain-related fear of movement, contribute to the development of chronic musculoskeletal pain and disability The FAM describes the theoretic method by which pain is catastrophically misinterpreted, therefore giving rise to fear of pain, kinesiophobia, avoidance, and hypervigilance. The model describes 2 categories of people based on their response to pain: confronters and avoiders. Confronters view pain as nonthreatening, tend to experience less interference with daily activities, and thus have a quicker recovery. Avoiders interpret pain as threatening and resort to adaptive behaviors, therefore avoiding activities that the patient associates with pain. Patients with elevated levels of fear may resort to avoidance behaviors and develop further pain and disability. This model has been validated in patients with low back, 9,10 shoulder-, 14 and knee-related disability, 12 but little evidence exists to make this association in patients with foot and/or ankle disability. We hypothesize that a similar finding may be true in patients with foot and/or ankle disability. Since the foot and ankle play a vital role in locomotion and many sportsrelated activities, we hypothesized that kinesiophobia would significantly contribute to lower-extremity disability. This may represent a modifiable risk factor for the development of chronic disability related to foot and/or ankle pain, and thus may represent an appropriate and important rehabilitation target. The influence of factors such as pain and ROM on foot- and ankle-related disability has been established. The unique con- BMI FAM LEFS ROM TSK TSK-11 List of Abbreviations body mass index fear avoidance model Lower Extremity Functional Scale range of motion Tampa Scale of Kinesiophobia Shortened TSK

2 558 FEAR AND FOOT AND ANKLE DISABILITY, Lentz tribution of pain-related fear of movement to disability beyond ROM and pain, however, is unclear. Therefore, the purpose of this study was to examine the contribution of kinesiophobia to self-reported disability related to foot and/or ankle pathology after controlling for demographic variables, pain intensity, and ROM. METHODS A retrospective clinical database review was performed to identify patients treated for foot- and ankle-related disability in the department of physical therapy at UF & Shands Orthopaedics and Sports Medicine Institute. Records retrieved during this review included demographic, physical impairment, and self-report measures collected at the time of initial evaluation as part of the routine physical therapy examination. All data were originally collected in a prospective fashion upon initial evaluation and entered into the clinical database. The records were later queried for the information presented in this study. All patients were seen for physical therapy during a 6-month period. Subjects were eligible to be included in the study if they were referred to physical therapy with a diagnosis related to the foot and/or ankle, or subjective complaints of foot- and/or ankle-related disability. Subjects records were excluded if they had a history of foot or ankle surgery in order to capture the largest nonoperative general population sample. Records with incomplete data were also excluded. This study involved routinely collected data from the clinical encounter, and no data were collected for research purposes exclusively. This was an exempt study under Institutional Review Board approval at the University of Florida, and patients were not required to provide informed consent. Measures Upon initial evaluation, demographic information (age, sex, involved side, height, weight) was collected, as well as duration of symptoms and mechanism of injury onset (traumatic or atraumatic). Additionally, a standardized battery of clinical measures of foot and ankle function and self-reported questionnaires was administered as a component of routine care. Three physical therapists specializing in the treatment of the foot and ankle were involved in data collection. Range of Motion ROM measures for plantar flexion and dorsiflexion were measured with a standard goniometer using standard positioning and landmarks. 21 Goniometric measurements have been shown to be a reliable measure of joint motion at the ankle. 22 Dorsiflexion ROM has been previously shown to contribute to disability in patients with plantar fasciitis 7 and chronic heel pain. 1 An active ROM screen was performed first for each indicated measure, followed by goniometric measurements of passive ROM with overpressure. Each goniometric measure was then expressed as an index of involved side divided by uninvolved side to be sensitive to side-to-side deficits. Plantar flexion and dorsiflexion side-to-side deficits were added to create an overall side-to-side deficit. Body Mass Index BMI was calculated by dividing the subject s weight in kilograms by height in meters squared. BMI has been shown to contribute to self-reported disability related to plantar fasciitis. 6,7 Self-Report Questionnaires Patients were asked to complete questionnaires related to pain intensity, foot and ankle function, and kinesiophobia. This information was collected by self-report questionnaire upon patient intake, before evaluation by the physical therapist. Per standard clinical and Institutional Review Board protocols, patients were told these measures were used for evaluation purposes, including helping the therapist to set goals for therapy and track progress. Patients were also informed that the information collected in the questionnaires may be used in a de-identified manner for future research studies. Pain intensity was measured on an 11-point numeric pain rating scale (0 10), with higher numbers indicating higher pain intensity. Current pain intensity, as well as best and worst pain intensity since onset of symptoms, was collected. Subjective pain intensity ratings were averaged from current, best, and worst pain score for each subject because this method best suited our sample. 23 The numeric pain rating scale has been found to be a reliable and valid measure of clinical pain intensity. 24,25 Ankle function was determined by the LEFS. The LEFS is a 20-question, 80-point scale that measures self-reported impact of lower-extremity dysfunction on everyday activities. Items are scored on a 5-point scale from 0 (extreme difficulty or unable to perform activity) to 4 (no difficulty). It has been found to have excellent internal consistency (.96), testretest reliability (intraclass correlation coefficient,.88), and construct validity (r.80); a 9-point change was determined to be clinically meaningful. 26,27 Scores range from 0 to 80, and higher scores indicate lower levels of disability. Kinesiophobia was measured with the shortened version of the TSK, the TSK-11. The TSK-11 is an 11-item, 44-point questionnaire that examines 2 separate domains related to movement: fear of reinjury and fear of pain. The items are scored on a 4-point scale from 1 (strongly disagree) to 4 (strongly agree). Scores range from 11 to 44 points, with lower scores indicating lower levels of kinesiophobia. The TSK-11 excludes 6 psychometrically poor questions from the original TSK. The TSK-11 has demonstrated similar factor structure, reliability and validity to the original version of the TSK. 28 The TSK-11 has been used extensively to measure fear of movement/reinjury in other orthopedic populations, such as individuals with low back pain, shoulder pain, and lower-extremity disability. 11,13,15,16,29 Statistical Analysis Statistical analyses were conducted with SPSS for Windows, version a Descriptive statistics were generated for demographic, physical impairment, pain, and self-report questionnaire data. Bivariate correlations were measured between each physical impairment measure, demographic variables, and TSK-11 and LEFS scores using Pearson correlation coefficients. Associations between subjects LEFS scores were also compared on the basis of sex, chronicity, and mechanism of injury onset using point biserial correlations. A hierarchical regression model was built using variables shown in previous studies to be associated with function in this population. Variables with statistically significant correlations (P.05) with the dependent variable LEFS score were also included. These inclusion criteria were used to avoid the exclusion of any potentially important variables. Demographic variables (age, chronicity of symptoms, BMI) were entered into the model at the first step, followed by impairment measures (pain intensity, combined ROM deficit). Kinesiophobia (TSK-11 score) was added in the third and final step. Changes in r 2 were reported after each step of the regression model to determine the influence of additional variables.

3 FEAR AND FOOT AND ANKLE DISABILITY, Lentz 559 Table 1: Demographic Data and Mean Impairment and Outcome Measure Scores Characteristics Values Age (y) Sex (women) 45 (53) BMI (kg/m 2 ) Mechanism of injury onset (traumatic) 62 (73) Chronicity of symptoms ( 3mo) 54 (64) Average pain intensity (0 10) Modified TSK-11 (11 44) Plantar flexion ROM deficit (deg) Dorsiflexion ROM deficit (deg) Combined ROM deficit (deg) LEFS (0 80) NOTE. Values are mean SD for continuous variables and n (%) for dichotomous variables. RESULTS A total of 155 subjects were identified with a medical diagnosis and/or subjective complaint of foot- or ankle-related disability. Seventy potential subjects were excluded because of incomplete data sets (n 23) or a history of foot or ankle surgery (n 47). Eighty-five subjects (40 men; mean age, 33y; range, 16 77y) met the inclusion criteria and were included in subsequent analyses. This sample of subjects with foot- or ankle-related disability represented approximately 9% of all patients referred to our clinic for physical therapy. Demographic data and mean impairment and outcome measure scores are listed in table 1. A breakdown of diagnoses for the included sample is reported in table 2. Traumatic symptom onset was present in 62 subjects (73%). Symptom onset was less than or equal to 3 months for 54 subjects (64%). The average TSK-11 score was 22.3 (range, 11 34). The average LEFS total score for the sample was 47.5 (range, 8 77). Correlations are shown in table 3. The LEFS score had small to moderate correlations with each of the continuous measures except BMI. The results of the linear regression are shown in table 4. Demographic variables (chronicity of symptoms, age, BMI) collectively contributed approximately 9% of the variance in disability scores. Average pain intensity and overall ROM deficit contributed an additional 11% of the variance, and TSK-11 scores contributed an additional 14%. In the overall model, age (.29, P.004), chronicity of symptoms (.23, P.024), ROM deficit (.28, P.003), and TSK-11 (.40, P.001) explained 34% of the total variance in the LEFS score (P.001). Pain-related fear of movement was the strongest single contributor to disability in this group of patients. The standardized beta for chronicity of symptoms showed a positive relationship with LEFS scores, indicating that a more acute onset of symptoms was associated with higher levels of disability. Age, ROM deficit, and TSK scores were all inversely related to the LEFS score. DISCUSSION The purpose of this study was to examine the unique influence of pain-related fear of movement on disability after accounting for demographics, pain, and physical impairment variables in a sample of patients with foot- and/or ankle-related disability. Our hypothesis was that pain-related fear of movement could be used to explain foot and/or ankle disability. We believe this hypothesis was generally supported by the findings of the study, which demonstrate a significant relationship between fear of pain and disability, even after considering the influence of demographics, pain intensity, and physical impairment variables. The findings in this study of a rehabilitation population support the influence of established contributors to disability in general practice such as age and ROM; however, pain-related fear of movement, as measured by the TSK-11, was the strongest single predictor of disability at baseline. This study is the first that we are aware of to examine the relationship of demographics, baseline physical impairments, and kinesiophobia to disability in a large clinical sample of individuals with foot and/or ankle pain. The outcomes of this study lend support to previous findings that demonstrated the potential for the FAM to be applicable across a multitude of musculoskeletal pathologies including those involving low back pain, 30 knee pain, 12 and shoulder pain. 15,16 The magnitude of the impact of pain-related fear in rehabilitation is becoming clearer. The protective effects of this psychologic property, however, are not well understood. Fear of pain or reinjury conceivably facilitates self-selected behavior to reduce the potentially detrimental effects of pain or further injury. It is unclear at what, if any, stage of rehabilitation this behavior is beneficial. The outcomes of this study highlight the multifactorial biopsychosocial nature of disability in a population of individuals with foot and ankle disability. These factors include demographic, physical impairment, and psychologic variables. Certain factors identified in this study, such as ROM and pain-related fear, are potentially modifiable and represent important rehabilitation targets. Behavioral interventions have been developed and successfully implemented for patients with low back pain, for example. Specifically, graded exposure to activities of which the patient is fearful encourages a confrontation response in patients who would normally avoid an activity of daily living. The treatment generally consists of concurrent patient education and encouragement to perform part of an activity of which they are fearful or an activity that is related to this specific fear. For Table 2: List of Diagnoses for Included Subjects Diagnosis No. of Subjects (%) Sprain (total) 34 (40) Lateral 7 Syndesmotic/lateral 5 Not specified 22 Fracture (total) 20 (24) Fibula 5 Metatarsal 4 Tibia/fibula 3 Midfoot 2 Calcaneus 2 Tibia 1 Not specified 3 Tendonitis (total) 11 (13) Achilles 5 Peroneal 3 Tibialis anterior 2 Posterior tibialis 1 Plantar fasciitis 9 (11) Strain (total) 3 (4) Peroneal 1 Not specified 2 Heel pain (not specified) 2 (2) Degenerative joint disease 2 (2) Instability 2 (2) Ankle pain (not specified) 2 (2)

4 560 FEAR AND FOOT AND ANKLE DISABILITY, Lentz Table 3: Point Biserial Correlations Among Demographic, Impairment, and Self-Report Measures Sex BMI Chronicity MOI Pain ROM deficit TSK-11 LEFS Age * * Sex * BMI.246* Chronicity.254*.226*.245* MOI.263*.235* Pain * ROM deficit * TSK NOTE. Sex (0 women, 1 men); chronicity symptom chronicity (0 3mo, 1 3mo); MOI, (0 nontraumatic, 1 traumatic); pain average rating of worst, best, and current pain intensity; ROM deficit deficit of total ankle motion in the sagittal plane calculated as noninvolved to involved. Abbreviation: MOI, mechanism of injury onset. *Significant correlation, P.05. Significant correlation, P.01. example, a patient with ankle pain who will not attempt hopping for distance because of fear of pain in the ankle might be encouraged to begin bouncing on a trampoline or perform active plantar flexion while in single-leg stance. Once the patient indicates that the fear is reduced, the complexity and difficulty of the task can be progressed in a systematic fashion. A recent commentary describes graded exposure intervention for patients with low back pain in greater detail. 31 Study Limitations There are limitations to consider when interpreting the results of this study. The data in this study were collected retrospectively as part of a database review. This cross-sectional study did not assess factors that predict long-term outcome, and thus the current study design precludes us from making any conclusions regarding the predictive ability of these impairments for short- or long-term outcomes in this population. Also, this sample included only subjects with nonoperative foot and ankle pain. The influence of these factors in Table 4: Results of the Hierarchical Regression Modeling Predicting LEFS Model Standardized Coefficients P R 2 Change P 1 (Constant) Age Chronicity BMI (Constant) Age Chronicity BMI Pain ROM Index (Constant) Age Chronicity BMI Pain ROM Index TSK NOTE. Chronicity 3 months since onset; pain average rating of worst, best, and current pain intensity; ROM deficit ratio of total ankle motion in the sagittal plane calculated as noninvolved to involved. other populations, such as people with a history of foot and ankle surgery, should be examined. The relatively small amount of total variance explained by our model further highlights the need to include additional demographic, biological, psychologic, and social constructs in future studies. Particularly, factors such as legal involvement related to the injury, race/ethnicity, socioeconomic status, and education may be considered. Workers compensation status has been shown to be a significant predictor related to foot and ankle disability; however, because of the low percentage of patients with workers compensation claims seen in our clinic, we excluded this variable in our analysis. Another limitation to this model is that we were unable to include other psychologic factors relevant to the FAM. Most notable of these is pain catastrophizing, which has a documented influence on musculoskeletal pain in studies of patients with knee 32 and back pain. 33,34 In the FAM model, catastrophizing about pain often precedes pain-related fear, especially pain-related fear of movement and reinjury. Fear and the expectation of adverse consequences from increasing activities may cause avoidance of physical activities, contributing to self-perceptions of disability. We did not specifically measure catastrophizing in this current study and consequently are unable to comment about the strength or the direction of relationship between kinesiophobia and catastrophizing in subjects with nonsurgical ankle pain. Despite this limitation, we believe this study provides support for the FAM model in this group of patients. Finally, we acknowledge the inherent limitations of self-report measures, such as memory error and recall bias, that may skew results related to pain and disability for subjects with a longstanding history of foot- and ankle-related disability. CONCLUSIONS This study examined the influence of demographics, various physical impairment measures, and kinesiophobia on self-reported disability in patients with foot- and/or ankle-related pathologies. Kinesiophobia, as measured by the TSK-11, as well as age, ROM, and chronicity of symptoms, was found to play a significant role in predicting concurrent baseline disability in this cohort. Clinicians should consider examination of and interventions for kinesiophobia, in addition to ROM, in patients who present to secondary and tertiary health care settings with foot- and/or ankle-related disability. The FAM was initially developed to help describe the theoretic method by which psychologic variables contribute to avoidance behavior and facilitate long-term disability. Future studies should include other psychosocial constructs that have

5 FEAR AND FOOT AND ANKLE DISABILITY, Lentz 561 been proposed as factors in the FAM such as pain catastrophizing, anxiety, psychologic distress, somatization, and selfefficacy. Furthermore, subgroup classifications, such as runners with foot and/or ankle pain or those people with workers compensation claims, may elucidate different relationships between fear and disability than a general population cohort. Because of the limitations inherent in a cross-sectional study, future studies should examine the prognostic value of fear avoidance beliefs and physical impairment in predicting the transition from acute to chronic foot and/or ankle pain. Acknowledgments: We thank Tim Day, PT, Mike Hodges, PT, MHS, CSCS, and Debi Jones, PT, DPT, for database administration and data input. References 1. Irving DB, Cook JL, Menz HB. Factors associated with chronic plantar heel pain: a systematic review. J Sci Med Sport 2006;9: Garrick JG, Requa RK. The epidemiology of foot and ankle injuries in sports. Clin Podiatr Med Surg 1989;6: Anadacoomarasamy A, Barnsley L. Long term outcomes of inversion ankle injuries. Br J Sports Med 2005;39:e Rano JA, Fallat LM, Savoy-Moore RT. Correlation of heel pain with body mass index and other characteristics of heel pain. J Foot Ankle Surg 2001;40: Keysor JJ, Dunn JE, Link CL, Badlissi F, Felson DT. Are foot disorders associated with functional limitation and disability among community-dwelling older adults? J Aging Health 2005; 17: Riddle DL, Pulisic M, Sparrow K. Impact of demographic and impairment-related variables on disability associated with plantar fasciitis. Foot Ankle Int 2004;25: Riddle DL, Pulisic M, Pidcoe P, Johnson RE. Risk factors for plantar fasciitis: a matched case-control study. J Bone Joint Surg Am 2003;85: Crombez G, Vlaeyen JW, Heuts PH, Lysens R: Pain-related fear is more disabling than pain itself: evidence on the role of painrelated fear in chronic back pain disability. Pain 1999;80: Swinkels-Meewisse IE, Roelofs J, Verbeek AL, Oostendorp RA, Vlaeyen JW. Fear of movement/(re)injury, disability and participation in acute low back pain.pain 2003;105: Vlaeyen JW, Kole-Snijders AM, Boeren RG, van Eek H: Fear of movement/(re)injury in chronic low back pain and its relation to behavioral performance. Pain 1995;62: Chmielewski TL, Jones D, Day T, Tillman SM, Lentz TA, George SZ. The association of pain and fear of movement/reinjury with function during anterior cruciate ligament reconstruction rehabilitation. J Orthop Sports Phys Ther 2008;38: Kvist J, Ek A, Sporrstedt K, Good L. Fear of re-injury: a hindrance for returning to sports after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc 2005;13: Lentz TA, Tillman SM, Indelicato PA, Moser MW, George SZ, Chmielewski TL. Factors associated with function after anterior cruciate ligament reconstruction. Sports Health: A Multidisciplinary Approach 2009;1: Feleus A, van Dalen T, Bierma-Zeinstra SM, et al. Kinesiophobia in patients with non-traumatic arm, neck and shoulder complaints: a prospective cohort study in general practice. BMC Musculoskelet Disord 2007;8: George SZ, Dover GC, Fillingim RB. Fear of pain influences outcomes after exercise-induced delayed onset muscle soreness at the shoulder. Clin J Pain 2007;23: Lentz TA, Barabas JA, Day T, Bishop MD, George SZ. The relationship of pain intensity, physical impairment, and painrelated fear to function in patients with shoulder pathology. J Orthop Sports Phys Ther 2009;39: Kori SH, Miller RP, Todd DD. Kinisophobia: a new view of chronic pain behavior. Pain Manag 1990;3: Leeuw M, Goossens M, Linton S, Crombez G, Boersma K, Vlaeyen J. Fear-avoidance model of musculoskeletal pain: current state of scientific evidence. J Behav Med 2007;30: Lethem J, Slade PD, Troup JD, Bentley G. Outline of a fearavoidance model of exaggerated pain perception--i. Behav Res Ther 1983;21: Vlaeyen JW, Kole-Snijders AM, Rotteveel AM, Ruesink R, Heuts PH. The role of fear of movement (re)injury in pain disability. J Occup Rehabil 1995;5: Norkin CC, White DJ. Measurement of joint motion: a guide to goniometry. 3rd ed. Philadelphia: FA Davis; Martin RL, McPoil T. Reliability of goniometric measurements: a literature review. J Am Podiatr Med Assoc 2005;95: Jensen MP, Turner JA, Romano JM, Fisher LD. Comparative reliability and validity of chronic pain intensity measures. Pain 1999;83: McCormack HM, Horne DJ, Sheather S. Clinical applications of visual analogue scales: a critical review. Psychol Med 1988;18: Farrar JT, Young JP Jr, LaMoreaux L, Werth JL, Poole RM. Clinical importance of changes in chronic pain intensity measured on an 11-point numerical pain rating scale. Pain 2001;94: Binkley JM, Stratford PW, Lott SA, Riddle DL. The Lower Extremity Functional Scale (LEFS) scale development, measurement properties, and clinical application. Phys Ther 1999;79: Yeung TS, Wessel J, Stratford P, McDermid J. Reliability, validity, and responsiveness of the Lower Extremity Functional Scale for inpatients of an orthopaedic rehabilitation ward. J Orthop Sports Phys Ther 2009;39: Woby SR, Roach NK, Urmston M, Watson PJ. Psychometric properties of the TSK-11: a shortened version of the Tampa Scale for Kinesiophobia. Pain 2005;117: Bot S, Van Der Waal J, Terwee C, et al. Predictors of outcome in neck and shoulder symptoms. Spine 2005;30:E Vlaeyen JW, Linton SJ. Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art. Pain 2000;85: George SZ, Zeppieri G. Physical therapy utilization of graded exposure for patients with low back pain. J Orthop Sports Phys Ther 2009;39: Keefe FJ, Lefebvre JC, Egert JR, Affleck G, Sullivan MJ, Caldwell DS. The relationship of gender to pain, pain behavior, and disability in osteoarthritis patients: the role of catastrophizing. Pain 2000;87: Pincus T, Burton AK, Vogel S, Field AP. A systematic review of psychological factors as predictors of chronicity/disability in prospective cohorts of low back pain. Spine 2002;27:E van der Windt D, Kuijpers T, Jellema P, van der Heijden G, Bouter L. Do psychological factors predict outcome in both lowback pain and shoulder pain? Ann Rheum Dis 2007;66: Supplier a. SPSS Inc, 233 S Wacker Dr, 11th Fl, Chicago, IL