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International Journal of Sports Physical Therapy logoLink to International Journal of Sports Physical Therapy
. 2023 Feb 1;18(1):92–101. doi: 10.26603/001c.68045

The Comparison of Psychological Barriers Between Individuals with a History of Anterior Knee Pain, Anterior Cruciate Ligament Reconstruction, and Healthy Individuals

Emma F Zuk 1,2,✉, Sungwan Kim 1,2, Julie P Burland 1,2, Neal R Glaviano 1,2
PMCID: PMC9897036  PMID: 36793558

Abstract

Background

Psychological barriers due to anterior knee pain (AKP) and anterior cruciate ligament reconstruction (ACLR) may have a direct impact on an individual’s return to physical activity. A comprehensive understanding of these psychological barriers in individuals with AKP and ACLR may help clinicians to develop and implement better treatment strategies to address deficits that may exist in these individuals.

Hypothesis/Purpose

The primary purpose of this study was to evaluate fear-avoidance, kinesiophobia, and pain catastrophizing in individuals with AKP and ACLR compared with healthy individuals. The secondary purpose was to directly compare psychological characteristics between the AKP and ACLR groups. It was hypothesized that 1) individuals with AKP and ACLR would self-report worse psychosocial function than healthy individuals and 2) the extent of the psychosocial impairments between the two knee pathologies would be similar.

Study Design

Cross-sectional study.

Methods

Eighty-three participants (28 AKP, 26 ACLR, and 29 healthy individuals) were analyzed in this study. Fear avoidance belief questionnaire (FABQ) with the physical activity (FABQ-PA) and sport (FABQ-S) subscales, Tampa scale of Kinesiophobia (TSK-11) and pain catastrophizing scale (PCS) assessed psychological characteristics. Kruskal-Wallis tests were used to compare the FABQ-PA, FABQ-S, TSK-11, and PCS scores across the three groups. Mann-Whitney U tests were performed to determine where group differences occurred. Effect sizes (ES) were calculated with the Mann-Whitney U z-score divided by the square root of the sample size.

Results

Individuals with AKP or ACLR had significantly worse psychological barriers compared to the healthy individuals for all questionnaires (FABQ-PA, FABQ-S, TSK-11, and PCS) (p<0.001, ES>0.86). There were no differences between the AKP and ACLR groups (p≥0.67), with a medium ES (-0.33) in the FABQ-S between AKP and ACLR groups.

Conclusion

Greater psychological scores indicate impaired psychological readiness to perform physical activity. Clinicians should be aware of fear-related beliefs following knee-related injuries and are encouraged to measure psychological factors during the rehabilitation process.

Level of Evidence

2

Keywords: knee injury, fear avoidance, kinesiophobia, pain catastrophizing

INTRODUCTION

The knee is the most commonly injured joint in both male and female adults, accounting for 19% to 23% of all orthopedic injuries.1 Two of the most frequent musculoskeletal knee conditions are anterior knee pain (AKP), which incorporates patellofemoral pain, patellar subluxation, and patella dislocations, and anterior cruciate ligament injuries (ACL).2–4 AKP has an annual prevalence of 22.7%5 while over 250,000 ACL injuries occur each year.6 AKP is a multifactorial pathology linked to increase stress on the patellofemoral joint, resulting in pain,7 and recurrent or chronic symptoms.3 ACL injuries are often the result of direct or indirect trauma to the knee, often leading to surgical intervention (e.g., reconstruction) to restore stability and function of the knee.8 While the mechanism of injury between conditions differs, both present with similar clinical impairments. Individuals with AKP and ACL reconstruction (ACLR) often present with decreased self-reported function,7 lower extremity muscle weakness,7 reduced physical activity level7,9,10 and poor health-related quality of life.11,12 Additionally, both AKP13 and ACLR14 are suggested to result in increased risk for the development of knee osteoarthritis.

Although therapeutic interventions and surgical procedures aim to enhance physical function in individuals with AKP and ACLR, many individuals still report long-term disability.8,15 Restoration of functional outcomes and patient-reported satisfaction is one of the primary criteria for medical clearance for return to daily activities following knee pathologies.16–18 Unfortunately, many patients exhibit psychological impairments during their rehabilitation that can act as barriers to successful recovery.19 Both individuals with AKP and ACLR present with injury-related fear-avoidance, kinesiophobia, and pain catastrophizing.20–22 Greater psychological barriers in both patient populations has been associated with inability to resume pre-injury levels of sport, decreased physical activity engagement, and decreased health- or knee-related quality of life.8,23 Fear-avoidance is based off a psychiatric model that describes how individuals develop and maintain musculoskeletal pain as a result of avoiding behavior based on past pain experiences.24 Kinesiophobia is generally defined as fear of movement due to the pain experience25 whereas pain catastrophizing is depicted as magnifying pain and feeling helpless in the face of pain.26

Self-reported questionnaires to quantify psychological barriers have emerged as an important component for AKP11 and ACLR27 rehabilitation. These tools are frequently integrated into return to play testing with psychological barriers being predictive of athletes success in returning to sport17,28 and regaining optimal physical function.29 In recent literature, the decision to return to sport after ACLR has been strongly influenced by psychosocial factors.30 Additionally, elevated fear-avoidance beliefs and fear of reinjury are associated with increased risk of injury, impaired return to prior levels of performance, and reduced physical activity level.9,31–34 Over time psychological barriers and physical performance improve; however, the improvements do not exceed clinical thresholds and still present years following injury and treatment.35–37 This reinforces that physical performance should not be the lone post-operative outcome and that consideration of psychological consequences in those with knee pathologies should also be accounted for.30 Psychological characteristics amongst AKP and ACLR patient populations have been reported separately; however, it is unknown if similar psychological responses exist between two common knee conditions.

A comprehensive understanding of the psychological features in individuals with AKP and ACLR would help clinicians to develop and implement better treatment strategies to address deficits that may exist in these individuals. Therefore, the primary purpose of this study was to evaluate fear-avoidance, kinesiophobia, and pain catastrophizing in individuals with AKP and ACLR compared with healthy individuals. The secondary purpose was to directly compare psychological characteristics between the AKP and ACLR groups. We hypothesized that 1) individuals with AKP and ACLR would self-report worse psychosocial function than healthy individuals and 2) the extent of the psychosocial impairments between the two knee pathologies would be similar.

MATERIALS AND METHODS

Design

A survey was used to examine the influence of AKP and ACLR on fear-avoidance beliefs, kinesiophobia, and pain catastrophizing. Independent variables include each group: AKP, ACLR, and a no injury history group. Dependent variables include the fear-avoidance belief questionnaire (FABQ) with the physical activity (FABQ-PA) and sport (FABQ-S) subscales, Tampa scale of Kinesiophobia (TSK-11) and pain catastrophizing scale (PCS) scores. The reporting of the study adhered to the CHERRIES guidelines recommendations.38 The study was approved by each university’s Institutional Review Board (University of Connecticut and University of Toledo) and all participants provided informed consent via an online consent process. Participants were provided information regarding study purpose, estimated time for study completion, management of identifiable data, and contact information for the research team. Cookies or timestamps were not used in this study but duplicate IP addresses were extracted.

Procedures

Data were collected over an eight-month period from two large public universities (one in the Midwest and one in the Northeast) from college-aged students as part of a larger study evaluating musculoskeletal injury history. Recruitment for the study was conducted electronically via email, social media platforms, and research announcements at each university. A total of 502 participants between the two universities completed a survey, 83 participants met the purpose of this study and were included in this analysis.

Participants completed a self-reported injury history questionnaire. The injury history questionnaire was derived from previously reported measures and included 15 categories of sports-related injuries.39 Participants were asked to self-report if they had previously sustained any musculoskeletal conditions The questionnaire also collected basic demographic information (e.g., height, weight) and if participants were currently experiencing an injury that was resulting in pain. Participants who reported a previous musculoskeletal condition were also asked to indicate additional demographic information about the type and severity of injury, whether surgery was required, the number of times the injury occurred, and time since injury/surgery. All participants, regardless of injury status, then completed three previously validated patient reported outcome metrics developed to capture psychological function after musculoskeletal injury. The included the FABQ-PA, FABQ-S, TSK-11, PCS in an online data management system (Qualtrics). We adhered to previously described methods that no time restrictions were instituted for either AKP or ACLR history and included any self-reported knee injuries.40 Finally, the last question of the survey inquired about fear surrounding the COVID-19 pandemic.

The FABQ was developed as a 16-item dimension specific questionnaire that originally measured fear-avoidance beliefs related to physical activity and work in individuals with low back pain.41 A modified FABQ was utilized that replaced “low back” with “knee” in order to be joint specific in addition to modifying the work subscale to the sport subscale.18 The physical activity subscale (FABQ-PA) includes six questions that are scored out of 30 points while the sport subscale (FABQ-S) includes 10 questions that are scored out of 60 points. Greater scores reflect increased fear-avoidance beliefs related to physical activity and sport. The modified FABQ physical activity and sport subscales have acceptable internal consistency in individuals with a history of knee injuries.42

The TSK-11 is an 11-item dimension specific questionnaire that is used to measure kinesiophobia. The TSK-11 ranges from 11 to 44, with greater scores reflecting greater fear of movement and reinjury due to movement. The TSK-11 has demonstrated acceptable internal consistency (0.79) and reliability (0.81) in a chronic low back pain population.43 The TSK-11 has also been reported across various knee injury populations, including ACLR.44

Pain catastrophizing was measured with the PCS, which is a 13-item dimension specific questionnaire. The PCS ranges from 0 to 52, with greater scores representing greater catastrophic pain. The PCS has good to excellent test-retest reliability (ICC=0.88-.90), adequate validity (0.40-0.42) and excellent internal consistency (0.92).45 A total score above 30 indicates clinically relevant level of catastrophizing.

Participants were extracted based off who previously reported history of either AKP and/or ACLR and then extracted a third group of individuals without a history of musculoskeletal injury. AKP was defined as patellofemoral pain, history of patella subluxation / dislocation, or patella maltracking, but did not include patellar or quadriceps tendinopathy. Participant responses were excluded for missing data of the health history form or questionnaires. A total of 83 participants were included: 28 participants (13 males and 15 females) with a history of AKP, 26 participants (11 males and 15 females) with a history of ACLR and 29 participants (11 males and 18 females) without a history of musculoskeletal injury (i.e., healthy individuals).

Statistical Analysis

SPSS software (V.22; IBM Corporation, Armonk, NY) was used for all statistical analyses. We assessed normality of data with a Kolmogorov-Smirnov test, which identified non-normally distributed data. Separate Kruskal-Wallis tests were used to compare the FABQ-PA, FABQ-S, TSK-11, and PCS scores across the three groups (AKP, ACLR, Healthy). Mann-Whitney U tests were performed to determine where group differences occurred. We calculated non-parametric effect sizes to determine the magnitude of difference between groups for all questionnaires. Effect sizes were calculated with the Mann-Whitney U z-score divided by the square root of the group size. Effect sizes were interpreted as small (|0.10-0.29|). medium (|0.30-0.49|), and large (|≥0.50|).46 Descriptive statistics for all four questionnaires (FABQ-PA, FABQ-S, TSK-11, and PCS) were reported as medians, along with 25% and 75% interquartile ranges. Alpha for all analyses was set a priori as p≤0.05 meaning there is a 5% chance that the significant findings were due to error.

RESULTS

Descriptive demographics between groups are reported in Table 1, and there were no differences in age or sex across the three groups, p=0.72. The AKP group included 15 cases of patellofemoral pain, 10 cases with history of patella subluxation (n=7) or dislocation (n=3) and one case of patella maltracking. There was a significant interaction effect between injury history and questionnaire (FABQ-PA, FABQ-S, TSK-11, and PCS) interaction effect present, p<0.001 (Table 2). Participants with a history of AKP or ACLR had significantly worse scores compared to the healthy group for all questionnaires; however, there were no differences between the AKP or ACLR groups (Figure 1).

Table 1. Descriptive demographics between groups.

Healthy
(n=29) 		AKP
(n=28) 		ACLR
(n=26)
Males/Females 11/18 13/15 11/15
Age, years 20.7±2.2 21.2±2.5 20.8±2.5
Participants with multiple MSK injuries
        Number of additional MSK injuries		 0
0		 7
3.2±1.7		 5
2.6±0.8
Time since injury NA NA 21.8±13.4
Time before pain free NA 8.6±4.5* NA
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*7 cases of AKP (all self-reported as patellofemoral pain, reported they were not pain free)

Table 2. Comparison of psychological characteristics.

Median
(Interquartile Range)		 Mann-Whitney U Mann-Whitney U Mann-Whitney U
FABQ-PA* Healthy vs. AKP Healthy vs. ACLR AKP vs. ACLR
Healthy (n=29) 0.00 (0.00-6.00) p<0.001
Z = -6.535
ES = -1.20		 p<0.001
Z = -5.549
ES = -1.04		 p=0.167
Z = -1.381
ES = -0.27
AKP (n=28) 14.50 (13.00-18.75)
ACLR (n=26) 13.00 (9.50-16.25)
FABQ-S*
Healthy (n=29) 0.00 (0.00-8.50) p<0.001
Z = -5.502
ES = -1.02		 p<0.001
Z = -5.567
ES = -1.05		 p=0.087
Z = -1.711
ES = -0.33
AKP (n=28) 23.00 (19.00-28.00)
ACLR (n=26) 21.00 (16.00-23.00)
TSK-11*
Healthy (n=29) 12.00 (11.00-16.50) p<0.001
Z = -5.095
ES = -0.94		 p<0.001
Z = -5.660
ES = -1.06		 p=0.670
Z = -.426
ES = -0.08
AKP (n=28) 25.00 (16.50-28.75)
ACLR (n=26) 23.00 (21.00-25.50)
PCS*
Healthy (n=29) 0.00 (0.00-9.50) p<0.001
Z = -5.265
ES = -0.97		 p<0.001
Z = -4.602
ES = -0.86		 p=0.182
Z = -1.336
ES =-0.26
AKP (n=28) 21.50 (13.00-31.00)
ACLR (n=26) 14.00 (9.00-25.25)
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* Kruskal-Wallis test demonstrated significant differences, p<.05

FABQ-PA: Fear-Avoidance Belief Questionnaire-Physical Activity, FABQ-S: Fear-Avoidance Belief Questionnaire-Sport, TSK: Tampa Scale of Kinesiophobia, PCS: Pain Catastrophizing Scale, AKP: Anterior Knee Pain, ACLR: Anterior Cruciate Ligament Reconstruction, Z: Z-Score, ES: Effect Size

Figure 1.

Figure 1.

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Figure 1a: FABQ-PA; Figure 1b: FABQ-S; Figure 1c: TSK-11; Figure 1d: PCS between AKP, ACL and Health Individuals.

FABQ-PA: Fear Avoidance Belief Questionnaire – Physical Activity; FABQ-S: Fear Avoidance Belief Questionnaire – sport; TSK-11: Tampa Scale of Kinesiophobia; PCS: Pain Catastrophization Scale; AKP: Anterior Knee Pain; ACL: Anterior Cruciate Ligament

There were large magnitude effect sizes with the healthy versus AKP (ES= -1.20 to -0.94) and healthy versus ACLR (ES= -1.06 to -0.86) group comparisons. There was a medium effect size (ES= -0.33) in the FABQ-S between the AKP and ACLR groups, but small effect sizes for the remaining questionnaires (ES= -0.27 to -0.08).

DISCUSSION

College-aged individuals with a history of AKP or ACLR report elevated fear-avoidance, kinesiophobia, and pain catastrophizing compared to healthy individuals. There were no statistical or clinically meaningful differences in fear-avoidance, kinesiophobia, or pain catastrophizing between AKP and ACLR groups; however, there was a medium effect that individuals with AKP had a greater FABQ-S score compared to the individuals with ACLR.

AKP and ACLR groups exhibited greater scores in the FABQ-PA, FABQ-S, TSK-11 and PCS compared to the healthy group, which is consistent with previous literature. The findings emphasize the importance of assessing psychological factors in patients with knee pathologies, as various constructs may be present throughout the rehabilitation process.28,47 Both the AKP and ACLR groups had elevated scores across the four questionnaires but did not differ statistically between groups; however, there were small-to-moderate clinical differences in the FABQ-PA, FABQ-S and PCS scores.

There was a wide range in scores across the AKP and ACLR groups for all four psychological scales (Figure 1). Clinical thresholds have been established for three of the four included questionnaires to identify individuals with elevated fear-avoidance beliefs, kinesiophobia, and pain catastrophizing. A threshold score of 15 on the FABQ-PA47 is used to identify individuals with elevated fear-avoidance beliefs while a score of 30 on the PSC26 quantifies pain catastrophizing. The TSK-11 has been divided into four subgroups: minimal (≤22), low (23-28), moderate (29-35) and high (≥36). Fourteen individuals (50%) with AKP exceeding the threshold for having elevated fear-avoidance beliefs, but more interestingly, no individual with AKP scored below a 9 on the FABQ-PA (Figure 1). This differs from the ACLR group who did not exceed threshold values fear-avoidance beliefs on the physical activity scale, suggesting that fear-avoidance beliefs might be more common in individuals with AKP. The fear-avoidance model may help explain these findings, as the recurring chronic pain may provide individuals with AKP more opportunities to confront or develop fear of their pain. However, it is difficult to determine if the fear-avoidance model contributes to this phenomenon without longitudinal data exploring severity and frequency of pain, physical activity level, return to sport or other factors that may contribute to fear of pain. Similar trends in the other scales were observed, with a greater number of individuals with AKP demonstrating moderate to high kinesiophobia (eight individuals with AKP compared to three ACLR individuals) (Figure 1c) and exceeding pain catastrophizing (eight individuals with AKP compared to four ACLR individuals) (Figure 1d). The small-to-moderate clinical differences in fear-avoidance beliefs and pain catastrophizing scores in the AKP group may be due to the included cohort. The AKP cohort mainly included individuals with patellofemoral pain, which results in pain during functional tasks that require knee flexion and lasts for years after initial diagnosis.23,48 Additionally, almost half of our AKP cohort were still experiencing pain at the time of survey completion, which may explain why they had greater psychological barriers.

Although both groups reported greater fear related beliefs compared to the healthy group, there was no statistical differences between AKP and ACLR groups. Therefore, regardless of knee pathology, individuals may benefit from psychological interventions to combat increased fear-avoidance, kinesiophobia, and catastrophic pain. Despite the lack of differences between groups, interventions are essential to minimize secondary consequences and poor long-term implications associated with elevated psychological domains. The fear-avoidance model shows the longitudinal influence of psychological status on outcome where elevated pain catastrophizing and fear of movement or reinjury led to a more chronic disability.49 Individuals with increased fear-avoidance may also be at an increased risk for physical inactivity by adapting strategies to minimize painful stimuli.7 Additionally, greater levels of fear-avoidance are associated with stiffened movement patterns, reduced knee, hip and trunk flexion,50 that may predispose individuals to secondary injuries and readiness to return to sport.51 To address the long-term consequences and improve outcomes, clinicians must assess psychological domains and integrate appropriate interventions for patients suffering from injury regardless of injury type. There are various interventions that clinicians may prescribe when treating psychological impairments in their patients, such as relaxation therapy, guided imagery, goal-setting, and cognitive behavioral therapy.52,53 Psychologically informed interventions have been beneficial at reducing FABQ-PA, TSK-11, and pain catastrophizing in adolescents with PFP,54 while in vivo exposure therapy reduces injury related fear in ACLR cohort.55 Additionally, pain neuroscience education for chronic musculoskeletal conditions reduces psychosocial factors and improved movement impairments.56 While there is limited research directly comparing interventions across AKP and ACLR groups, the lack of difference in psychological variables from our data suggests multiple interventions may be beneficial to patients with knee related injuries.

Interestingly, the healthy group had individuals who responded to some questions, resulting in scores above zero on the FABQ-PA, FABQ-S and PCS, and greater than 11 on the TSK-11. While individuals responded to some questions across the scales, most did not exceed the threshold scores that signify clinical classification. No healthy individuals exceeded the threshold for elevated fear-avoidance belief on the FABQ-PA.47 Two healthy participants would be classified as low kinesiophobia, scoring a 23 on the TSK-11, while the remaining 27 healthy participants would be classified as minimal kinesiophobia.57 Finally, no healthy participants exceeded the clinical threshold on PCS. Another possible explanation would be that the study was administered during the COVID-19 pandemic, which could account for the responses within the healthy individuals.58 Fear and stress are common responses when individuals are exposed to perceived threats or during uncertainty, which were common due to the pandemic. Fear and stress increased during the pandemic,59 which may impact both our pathological and healthy groups when completing fear-based questionnaires such as those included in our study. The final question in the survey inquired if participants had increased anxiety levels or depression due to COVID-19; however, there were significant differences depending on question responses.

While some relationships exist across psychological domains, fear-avoidance beliefs, kinesiophobia and pain catastrophizing are distinct constructs. Similar scores were observed in the FABQ, TSK-11 and PCS between both the AKP and ACLR groups; however, the selection of questionnaires may be specific to the type of pathology.60,61 Decreasing fear-avoidance beliefs specifically on the FABQ-PA, predicts function and pain of a standard intervention program in individuals with AKP. Additionally, lower pain catastrophizing four-weeks after ACLR were associated with better knee function 12-weeks post-surgery,35 while greater kinesiophobia increased the odds of identifying patients at risk for delayed progression in their rehabilitation program. The integration of psychological questionnaires in clinical practice may be a viable approach to predict success of traditional intervention programs or identify patients who warrant psychological interventions.62 These findings provide a baseline look into fear-avoidance beliefs, kinesiophobia, and pain catastrophizing; however further investigations are needed to determine if the scales selected correlate with responses from various intervention programs.

This study is not without limitations. Due to the perceptual scales and injury history questionnaire being self-reported, there is a risk of missing injuries or recall bias. We also did not acquire detailed data regarding pain severity or time since pain/injury which may influence these results. Patient reported outcome measures selected in this study may have been influenced by time since surgery and recurrent bouts of pain. Differences exist between the clinical presentation and duration of impairments between AKP and ACLR. Patients experiencing AKP have pain for years after diagnosis, suggesting greater duration of pain may provide more opportunities for the development of fear-avoidance behaviors. Additionally, within the ACLR group time since injury also may have influenced the results along with comorbidities associated with an ACL injury. Frequency of injuries was not controlled, which may have a compounding effect on the reported scores. Current physical activity was also not assessed, which may influence symptoms or psychological impairments in the included populations. Injury history within our participant recruitment was also not accounted for, which reduces the interval validity. However, this choice improves the external validity, as clinicians often treat individuals with ACLR or AKP that have experienced previous musculoskeletal conditions. Similarities in the number of participants with previous conditions between each group were not analyzed. Finally, there should be some caution with the generalizability of the findings, due to the cohort only including college aged individuals and the participants self-reporting their injury history.

CONCLUSION

College-aged individuals with a history of AKP or ACLR demonstrated greater fear-avoidance beliefs, kinesiophobia, and pain catastrophizing than healthy controls. There were no differences across the four questionnaires between individuals with AKP or ACLR, suggesting that despite the difference in the knee pathologies, psychological responses may be similar. Clinicians should be aware of fear-related beliefs following knee-related injuries and are encouraged to measure psychological factors during the rehabilitation process.

Conflicts of Interest

The authors have no conflicts of interest to disclose.

References

  1. Epidemiology of musculoskeletal injuries among sedentary and physically active adults. Hootman JENNIFER M., Macera CAROL A., Ainsworth BARBARA E., Addy CHERYL L., Martin MALISSA, Blair STEVEN N. May;2002 Medicine & Science in Sports & Exercise. 34(5):838–844. doi: 10.1097/00005768-200205000-00017. doi: 10.1097/00005768-200205000-00017. [DOI] [PubMed] [Google Scholar]
  2. Weiss Kaitlyn, Whatman Chris. Sports Medicine. 9. Vol. 45. Springer Science and Business Media LLC; Biomechanics associated with patellofemoral pain and ACL injuries in sports; pp. 1325–1337. [DOI] [PubMed] [Google Scholar]
  3. National athletic trainers' association position statement: management of individuals with patellofemoral pain. Bolgla Lori A., Boling Michelle C., Mace Kimberly L., DiStefano Michael J., Fithian Donald C., Powers Christopher M. Sep 1;2018 Journal of Athletic Training. 53(9):820–836. doi: 10.4085/1062-6050-231-15. doi: 10.4085/1062-6050-231-15. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. National athletic trainers' association position statement: Prevention of anterior cruciate ligament injury. Padua Darin A., DiStefano Lindsay J., Hewett Timothy E., Garrett William E., Marshall Stephen W., Golden Grace M., Shultz Sandra J., Sigward Susan M. Jan 1;2018 Journal of Athletic Training. 53(1):5–19. doi: 10.4085/1062-6050-99-16. doi: 10.4085/1062-6050-99-16. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Incidence and prevalence of patellofemoral pain: A systematic review and meta-analysis. Smith Benjamin E., Selfe James, Thacker Damian, Hendrick Paul, Bateman Marcus, Moffatt Fiona, Rathleff Michael Skovdal, Smith Toby O., Logan Pip. Jan 11;2018 PLoS One. 13(1):e0190892. doi: 10.1371/journal.pone.0190892. doi: 10.1371/journal.pone.0190892. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Understanding and preventing noncontact anterior cruciate ligament injuries: a review of the Hunt Valley II meeting, January 2005. Griffin Letha Y., Albohm Marjorie J., Arendt Elizabeth A., Bahr Roald, Beynnon Bruce D., DeMaio Marlene, Dick Randall W., Engebretsen Lars, Garrett William E., Hannafin Jo A., Hewett Tim E., Huston Laura J., Ireland Mary Lloyd, Johnson Robert J., Lephart Scott, Mandelbaum Bert R., Mann Barton J., Marks Paul H., Marshall Stephen W., Myklebust Grethe, Noyes Frank R., Powers Christopher, Shields Clarence Jr, Shultz Sandra J., Silvers Holly, Slauterbeck James, Taylor Dean C., Teitz Carol C., Wojtys Edward M., Yu Bing. Sep;2006 The American Journal of Sports Medicine. 34(9):1512–1532. doi: 10.1177/0363546506286866. doi: 10.1177/0363546506286866. [DOI] [PubMed] [Google Scholar]
  7. Knee joint and quadriceps dysfunction in individuals with anterior knee pain, anterior cruciate ligament reconstruction, and meniscus surgery: A cross-sectional study. Kim Sungwan, Kim Daeho, Park Jihong. Jan 1;2021 Journal of Sport Rehabilitation. 30(1):112–119. doi: 10.1123/jsr.2018-0482. doi: 10.1123/jsr.2018-0482. [DOI] [PubMed] [Google Scholar]
  8. Anterior cruciate ligament injury: Return to play, function and long-term considerations. Sepúlveda Fernando, Sánchez Luis, Amy Eduardo, Micheo William. 2017Current Sports Medicine Reports. 16(3):172–178. doi: 10.1249/jsr.0000000000000356. doi: 10.1249/jsr.0000000000000356. [DOI] [PubMed] [Google Scholar]
  9. Physical activity levels in individuals with and without patellofemoral pain. Glaviano Neal R., Baellow Andrea, Saliba Susan. Sep;2017 Physical Therapy in Sport. 27:12–16. doi: 10.1016/j.ptsp.2017.07.002. doi: 10.1016/j.ptsp.2017.07.002. [DOI] [PubMed] [Google Scholar]
  10. Bell David R., Pfeiffer Karin A., Cadmus-Bertram Lisa A., Trigsted Stephanie M., Kelly Adam, Post Eric G., Hart Joseph M., Cook Dane B., Dunn Warren R., Kuenze Christopher. The American Journal of Sports Medicine. 8. Vol. 45. SAGE Publications; Objectively measured physical activity in patients after anterior cruciate ligament reconstruction; pp. 1893–1900. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Quality of life in individuals with patellofemoral pain: A systematic review including meta-analysis. Coburn Sally L., Barton Christian J., Filbay Stephanie R., Hart Harvi F., Rathleff Michael S., Crossley Kay M. Sep;2018 Physical Therapy in Sport. 33:96–108. doi: 10.1016/j.ptsp.2018.06.006. doi: 10.1016/j.ptsp.2018.06.006. [DOI] [PubMed] [Google Scholar]
  12. Health-related quality of life after anterior cruciate ligament reconstruction: a systematic review. Filbay Stephanie R., Ackerman Ilana N., Russell Trevor G., Macri Erin M., Crossley Kay M. 2014The American Journal of Sports Medicine. 42(5):1247–1255. doi: 10.1177/0363546513512774. doi: 10.1177/0363546513512774. [DOI] [PubMed] [Google Scholar]
  13. Crossley Kay M. British Journal of Sports Medicine. 6. Vol. 48. BMJ; Is patellofemoral osteoarthritis a common sequela of patellofemoral pain? pp. 409–410. [DOI] [PubMed] [Google Scholar]
  14. Barenius Björn, Ponzer Sari, Shalabi Adel, Bujak Robert, Norlén Louise, Eriksson Karl. The American Journal of Sports Medicine. 5. Vol. 42. SAGE Publications; Increased risk of osteoarthritis after anterior cruciate ligament reconstruction: A 14-year follow-up study of a randomized controlled trial; pp. 1049–1057. [DOI] [PubMed] [Google Scholar]
  15. Factors that predict a poor outcome 5–8 years after the diagnosis of patellofemoral pain: a multicentre observational analysis. Lankhorst N E, van Middelkoop M, Crossley K M, Bierma-Zeinstra S M A, Oei E H G, Vicenzino B, Collins N J. 2016British Journal of Sports Medicine. 50(14):881–886. doi: 10.1136/bjsports-2015-094664. doi: 10.1136/bjsports-2015-094664. [DOI] [PubMed] [Google Scholar]
  16. Psychological factors are associated with return to pre-injury levels of sport and physical activity after ACL reconstruction. Baez Shelby E., Hoch Matthew C., Hoch Johanna M. 2020Knee Surgery, Sports Traumatology, Arthroscopy. 28(2):495–501. doi: 10.1007/s00167-019-05696-9. doi: 10.1007/s00167-019-05696-9. [DOI] [PubMed] [Google Scholar]
  17. Patient-reported outcomes, return-to-sport status, and reinjury rates after anterior cruciate ligament reconstruction in adolescent athletes: Minimum 2-year follow-up. Fones Lilah, Kostyun Regina O., Cohen Andrew D., Pace J. Lee. Nov 1;2020 Orthopaedic Journal of Sports Medicine. 8(11):2325967120964471. doi: 10.1177/2325967120964471. doi: 10.1177/2325967120964471. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Associates of physical function and pain in patients with patellofemoral pain syndrome. Piva Sara R., Fitzgerald G. Kelley, Irrgang James J., Fritz Julie M., Wisniewski Stephen, McGinty Gerald T., Childs John D., Domenech Manuel A., Jones Scott, Delitto Anthony. Feb;2009 Archives of Physical Medicine and Rehabilitation. 90(2):285–295. doi: 10.1016/j.apmr.2008.08.214. doi: 10.1016/j.apmr.2008.08.214. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Sullivan Michael J. L., Adams Heather, Thibault Pascal, Corbière Marc, Stanish William D. Journal of Occupational Rehabilitation. 1. Vol. 16. Springer Science and Business Media LLC; Initial depression severity and the trajectory of recovery following cognitive-behavioral intervention for work disability; pp. 60–71. [DOI] [PubMed] [Google Scholar]
  20. Psychological factors are associated with return to pre-injury levels of sport and physical activity after ACL reconstruction. Baez Shelby E., Hoch Matthew C., Hoch Johanna M. 2020Knee surgery, sports traumatology, arthroscopy. 28(2):495–501. doi: 10.1007/s00167-019-05696-9. doi: 10.1007/s00167-019-05696-9. [DOI] [PubMed] [Google Scholar]
  21. Patients’ perceptions of recovery following a 6-week exercise intervention for the treatment of patellofemoral pain: A mixed methods study. Louw Q.A., Leibbrandt D.C. 2019South African Journal of Physiotherapy. 75(1):1–8. doi: 10.4102/sajp.v75i1.684. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Psychological predictors of anterior cruciate ligament reconstruction outcomes: a systematic review. Everhart Joshua S., Best Thomas M., Flanigan David C. 2015Knee Surgery, Sports Traumatology, Arthroscopy. 23(3):752–762. doi: 10.1007/s00167-013-2699-1. doi: 10.1007/s00167-013-2699-1. [DOI] [PubMed] [Google Scholar]
  23. Factors that predict a poor outcome 5–8 years after the diagnosis of patellofemoral pain: a multicentre observational analysis. Lankhorst N E, van Middelkoop M, Crossley K M, Bierma-Zeinstra S M A, Oei E H G, Vicenzino B, Collins N J. 2016British Journal of Sports Medicine. 50(14):881–886. doi: 10.1136/bjsports-2015-094664. doi: 10.1136/bjsports-2015-094664. [DOI] [PubMed] [Google Scholar]
  24. Vlaeyen Johan W.S., Linton Steven J. Pain. 3. Vol. 85. Ovid Technologies (Wolters Kluwer Health); Fear-avoidance and its consequences in chronic musculoskeletal pain: a state of the art; pp. 317–332. [DOI] [PubMed] [Google Scholar]
  25. Kinesiophobia: a new view of chronic pain behavior. Kori S. 1990Pain Manage. 3:35–43. [Google Scholar]
  26. Sullivan M.J. The pain catastrophizing scale: user manual. McGill University; Montreal: [Google Scholar]
  27. Filbay S R, Culvenor A G, Ackerman I N, Russell T G, Crossley K M. British journal of sports medicine. 16. Vol. 49. BMJ; Quality of life in anterior cruciate ligament-deficient individuals: a systematic review and meta-analysis; pp. 1033–1041. [DOI] [PubMed] [Google Scholar]
  28. Differences in strength, patient-reported outcomes, and return-to-play rates between athletes with primary versus revision ACL reconstruction at 9 months after surgery. Carolan David, King Enda, Richter Chris, Franklyn-Miller Andy, Moran Ray, Jackson Mark. Sep 1;2020 Orthopaedic Journal of Sports Medicine. 8(9):2325967120950037. doi: 10.1177/2325967120950037. doi: 10.1177/2325967120950037. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Correlations of single-leg performance tests to patient-reported outcomes after primary anterior cruciate ligament reconstruction. Roe Chelsey, Jacobs Cale, Kline Paul, Lucas Kathryn, Johnson Darren, Ireland Mary L., Lattermann Christian, Noehren Brian. Feb 6;2020 Clinical Journal of Sport Medicine. 31(5):e265–e270. doi: 10.1097/jsm.0000000000000780. doi: 10.1097/jsm.0000000000000780. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Decision to Return to Sport After Anterior Cruciate Ligament Reconstruction, Part I: A Qualitative Investigation of Psychosocial Factors. Burland Julie P., Toonstra Jenny, Werner Jennifer L., Mattacola Carl G., Howell Dana M., Howard Jennifer S. May 1;2018 Journal of Athletic Training. 53(5):452–463. doi: 10.4085/1062-6050-313-16. doi: 10.4085/1062-6050-313-16. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Filbay Stephanie R, Crossley Kay M, Ackerman Ilana N. Journal of Physiotherapy. 2. Vol. 62. Elsevier BV; Activity preferences, lifestyle modifications and re-injury fears influence longer-term quality of life in people with knee symptoms following anterior cruciate ligament reconstruction: a qualitative study; pp. 103–110. [DOI] [PubMed] [Google Scholar]
  32. Kvist Joanna, Ek Anna, Sporrstedt Katja, Good Lars. Knee Surgery, Sports Traumatology, Arthroscopy. 5. Vol. 13. Springer Science and Business Media LLC; Fear of re-injury: a hindrance for returning to sports after anterior cruciate ligament reconstruction; pp. 393–397. [DOI] [PubMed] [Google Scholar]
  33. Fear of reinjury (kinesiophobia) and persistent knee symptoms are common factors for lack of return to sport after anterior cruciate ligament reconstruction. Flanigan David C., Everhart Joshua S., Pedroza Angela, Smith Tyler, Kaeding Christopher C. Aug;2013 Arthroscopy: The Journal of Arthroscopic & Related Surgery. 29(8):1322–1329. doi: 10.1016/j.arthro.2013.05.015. doi: 10.1016/j.arthro.2013.05.015. [DOI] [PubMed] [Google Scholar]
  34. Ardern Clare L, Österberg Annika, Tagesson Sofi, Gauffin Håkan, Webster Kate E, Kvist Joanna. British Journal of Sports Medicine. 22. Vol. 48. BMJ; The impact of psychological readiness to return to sport and recreational activities after anterior cruciate ligament reconstruction; pp. 1613–1619. [DOI] [PubMed] [Google Scholar]
  35. Fear avoidance and self-efficacy at 4 weeks after ACL reconstruction are associated with early impairment resolution and readiness for advanced rehabilitation. Chmielewski Terese L., George Steven Z. 2019Knee Surgery, Sports Traumatology, Arthroscopy. 27(2):397–404. doi: 10.1007/s00167-018-5048-6. doi: 10.1007/s00167-018-5048-6. [DOI] [PubMed] [Google Scholar]
  36. Longitudinal changes in psychosocial factors and their association with knee pain and function after anterior cruciate ligament reconstruction. Chmielewski Terese L., Zeppieri Giorgio, Jr., Lentz Trevor A., Tillman Susan M., Moser Michael W., Indelicato Peter A., George Steven Z. Sep 1;2011 Physical Therapy. 91(9):1355–1366. doi: 10.2522/ptj.20100277. doi: 10.2522/ptj.20100277. [DOI] [PMC free article] [PubMed] [Google Scholar]
  37. Filbay Stephanie, Kvist Joanna. Physical Therapy. 2. Vol. 102. Oxford University Press (OUP); Fear of reinjury following surgical and nonsurgical management of anterior cruciate ligament injury: An exploratory analysis of the NACOX multicenter longitudinal cohort study. [DOI] [PMC free article] [PubMed] [Google Scholar]
  38. The science of opinion: survey methods in research. Bryson Gregory L., Turgeon Alexis F., Choi Peter T. May 19;2012 Canadian Journal of Anesthesia/Journal canadien d'anesthésie. 59(8):736–742. doi: 10.1007/s12630-012-9727-3. doi: 10.1007/s12630-012-9727-3. [DOI] [PubMed] [Google Scholar]
  39. The impact of injury on health-related quality of life in college athletes. Houston Megan N., Hoch Johanna M., Van Lunen Bonnie L., Hoch Matthew C. Sep;2017 Journal of Sport Rehabilitation. 26(5):365–375. doi: 10.1123/jsr.2016-0011. doi: 10.1123/jsr.2016-0011. [DOI] [PubMed] [Google Scholar]
  40. Fear-avoidance beliefs and health-related quality of life in post-ACL reconstruction and healthy athletes: A case–control study. Hoch Johanna M., Houston Megan N., Baez Shelby E., Hoch Matthew C. 2019Journal of Sport Rehabilitation. 29(6):772–776. doi: 10.1123/jsr.2018-0491. doi: 10.1123/jsr.2018-0491. [DOI] [PubMed] [Google Scholar]
  41. Waddell Gordon, Newton Mary, Henderson Iain, Somerville Douglas, Main Chris J. Pain. 2. Vol. 52. Ovid Technologies (Wolters Kluwer Health); A fear-avoidance beliefs questionnaire (FABQ) and the role of fear-avoidance beliefs in chronic low back pain and disability; pp. 157–168. [DOI] [PubMed] [Google Scholar]
  42. Psychometric properties of the Tampa Scale for kinesiophobia and the fear-avoidance beliefs questionnaire in acute low back pain. Swinkels-Meewisse E.J.C.M, Swinkels R.A.H.M, Verbeek A.L.M, Vlaeyen J.W.S, Oostendorp R.A.B. Feb;2003 Manual Therapy. 8(1):29–36. doi: 10.1054/math.2002.0484. doi: 10.1054/math.2002.0484. [DOI] [PubMed] [Google Scholar]
  43. Psychometric properties of the TSK-11: a shortened version of the Tampa Scale for Kinesiophobia. Woby Steve R., Roach Neil K., Urmston Martin, Watson Paul J. Sep;2005 Pain. 117(1-2):137–144. doi: 10.1016/j.pain.2005.05.029. doi: 10.1016/j.pain.2005.05.029. [DOI] [PubMed] [Google Scholar]
  44. Analysis of shortened versions of the Tampa Scale for Kinesiophobia and Pain Catastrophizing Scale for patients following anterior cruciate ligament reconstruction. George Steven Z., Lentz Trevor A., Zeppieri Giorgio, Jr., Lee Derek, Chmielewski Terese L. Jan;2012 The Clinical Journal of Pain. 28(1):73–80. doi: 10.1097/ajp.0b013e31822363f4. doi: 10.1097/ajp.0b013e31822363f4. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Factor structure, reliability, and validity of the Pain Catastrophizing Scale. Osman Augustine, Barrios Francisco X., Kopper Beverly A., Hauptmann Wendy, Jones Jewel, O'Neill Elizabeth. 1997Journal of Behavioral Medicine. 20(6):589–605. doi: 10.1023/a:1025570508954. doi: 10.1023/a:1025570508954. [DOI] [PubMed] [Google Scholar]
  46. The effect size. Cohen J. 1988Statistical power analysis for the behavioral sciences. :77–83.
  47. George Steven Z., Stryker Sandra E. Journal of Orthopaedic & Sports Physical Therapy. 4. Vol. 41. Journal of Orthopaedic & Sports Physical Therapy (JOSPT); Fear-avoidance beliefs and clinical outcomes for patients seeking outpatient physical therapy for musculoskeletal pain conditions; pp. 249–259. [DOI] [PubMed] [Google Scholar]
  48. Glaviano Neal R., Bazett-Jones David M., Boling Michelle C. Journal of Science and Medicine in Sport. 5. Vol. 25. Elsevier BV; Pain severity during functional activities in individuals with patellofemoral pain: A systematic review with meta-analysis; pp. 399–406. [DOI] [PubMed] [Google Scholar]
  49. The fear-avoidance model of musculoskeletal pain: current state of scientific evidence. Leeuw Maaike, Goossens Mariëlle E. J. B., Linton Steven J., Crombez Geert, Boersma Katja, Vlaeyen Johan W. S. 2007Journal of Behavioral Medicine. 30(1):77–94. doi: 10.1007/s10865-006-9085-0. doi: 10.1007/s10865-006-9085-0. [DOI] [PubMed] [Google Scholar]
  50. Trigsted Stephanie M., Cook Dane B., Pickett Kristen A., Cadmus-Bertram Lisa, Dunn Warren R., Bell David R. Knee Surgery, Sports Traumatology, Arthroscopy. 12. Vol. 26. Springer Science and Business Media LLC; Greater fear of reinjury is related to stiffened jump-landing biomechanics and muscle activation in women after ACL reconstruction; pp. 3682–3689. [DOI] [PubMed] [Google Scholar]
  51. Worse knee confidence, fear of movement, psychological readiness to return-to-sport and pain are associated with worse function after ACL reconstruction. Hart Harvi F., Culvenor Adam G., Guermazi Ali, Crossley Kay M. Jan;2020 Physical Therapy in Sport. 41:1–8. doi: 10.1016/j.ptsp.2019.10.006. doi: 10.1016/j.ptsp.2019.10.006. [DOI] [PubMed] [Google Scholar]
  52. Goal setting and strategies to enhance goal pursuit in adult rehabilitation: summary of a Cochrane systematic review and meta-analysis. Levack W.M., Weatherall M., Hay-Smith J.C., Dean S.G., McPherson K., Siegert R.J. 2016Eur J Phys Rehabil Med. 52(3):400–16. [PubMed] [Google Scholar]
  53. Short-term psychological intervention: A study of long-term-injured competitive athletes. Johnson Urban. Aug;2000 Journal of Sport Rehabilitation. 9(3):207–218. doi: 10.1123/jsr.9.3.207. doi: 10.1123/jsr.9.3.207. [DOI] [Google Scholar]
  54. Effect of a psychologically informed intervention to treat adolescents with patellofemoral pain: A randomized controlled trial. Selhorst Mitchell, Fernandez-Fernandez Alicia, Schmitt Laura, Hoehn Jessica. Jul;2021 Archives of Physical Medicine and Rehabilitation. 102(7):1267–1273. doi: 10.1016/j.apmr.2021.03.016. doi: 10.1016/j.apmr.2021.03.016. [DOI] [PubMed] [Google Scholar]
  55. Implementation of In vivo exposure therapy to decrease injury-related fear in females with a history of ACL-Reconstruction: A pilot study. Baez Shelby, Cormier Marc, Andreatta Richard, Gribble Phillip, Hoch Johanna M. Nov;2021 Physical Therapy in Sport. 52:217–223. doi: 10.1016/j.ptsp.2021.09.009. doi: 10.1016/j.ptsp.2021.09.009. [DOI] [PubMed] [Google Scholar]
  56. The efficacy of pain neuroscience education on musculoskeletal pain: A systematic review of the literature. Louw Adriaan, Zimney Kory, Puentedura Emilio J., Diener Ina. Jun 28;2016 Physiotherapy Theory and Practice. 32(5):332–355. doi: 10.1080/09593985.2016.1194646. doi: 10.1080/09593985.2016.1194646. [DOI] [PubMed] [Google Scholar]
  57. Kinesiophobia severity categories and clinically meaningful symptom change in persons with achilles tendinopathy in a cross-sectional study: Implications for assessment and willingness to exercise. Chimenti R.L., Post A.A., Silbernagel K.G.., et al. Front Pain Res. 2021:57. doi: 10.3389/fpain.2021.739051. [DOI] [PMC free article] [PubMed] [Google Scholar]
  58. Psychosocial impact of COVID-19. Dubey Souvik, Biswas Payel, Ghosh Ritwik, Chatterjee Subhankar, Dubey Mahua Jana, Chatterjee Subham, Lahiri Durjoy, Lavie Carl J. Sep;2020 Diabetes & Metabolic Syndrome: Clinical Research & Reviews. 14(5):779–788. doi: 10.1016/j.dsx.2020.05.035. doi: 10.1016/j.dsx.2020.05.035. [DOI] [PMC free article] [PubMed] [Google Scholar]
  59. Peng Xiaodan, Liu Lili, Liang Shunwei, Chen Jianbin, Zhao Jingbo. Current Psychology. Vol. 2022. Springer Science and Business Media LLC; Longitudinal changes in fear and anxiety among Chinese college students during the COVID-19 pandemic: a one-year follow-up study; pp. 1–10. [DOI] [PMC free article] [PubMed] [Google Scholar]
  60. Quadriceps strength and kinesiophobia predict long-term function after ACL reconstruction: a cross-sectional pilot study. Van Wyngaarden Joshua J., Jacobs Cale, Thompson Katherine, Eads Molly, Johnson Darren, Ireland Mary Lloyd, Noehren Brian. 2021Sports Health: A Multidisciplinary Approach. 13(3):251–257. doi: 10.1177/1941738120946323. doi: 10.1177/1941738120946323. [DOI] [PMC free article] [PubMed] [Google Scholar]
  61. Chmielewski Terese L., Jones Debi, Day Tim, Tillman Susan M., Lentz Trevor A., George Steven Z. Journal of Orthopaedic & Sports Physical Therapy. 12. Vol. 38. Journal of Orthopaedic & Sports Physical Therapy (JOSPT); The association of pain and fear of movement/reinjury with function during anterior cruciate ligament reconstruction rehabilitation; pp. 746–753. [DOI] [PubMed] [Google Scholar]
  62. Bay Samantha, Kuster Lukas, McLean Neil, Byrnes Michelle, Kuster Markus Stefan. BMC Musculoskeletal Disorders. 1. Vol. 19. Springer Science and Business Media LLC; A systematic review of psychological interventions in total hip and knee arthroplasty; pp. 1–11. [DOI] [PMC free article] [PubMed] [Google Scholar]

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