The relationship between pain and associated characteristics of chronic ankle instability: A retrospective study

Exploring the interplay between ankle muscle strength, postural control, and pain intensity in chronic ankle instability: A comprehensive analysis

Background

Chronic Ankle Instability (CAI) is a common musculoskeletal condition characterized by recurring ankle sprains and impaired postural control (PC). Understanding the relationship between ankle muscle strength, PC, and the role of pain is essential for effective management.

Objectives

This prospective cross sectional study aimed to 1. Compare ankle isometric muscle strength (IMS) and PC between CAI and asymptomatic sides. 2. Assess the correlations between ankle IMS and PC and explore the potential mediating effect of pain in individuals with CAI.

Methods

A total of 44 individuals with CAI, were enrolled in the study. Ankle IMS (dorsiflexors, plantar flexors, invertors, and evertors) was measured using a dynamometer, while PC was evaluated using sway parameters (anterior-posterior and medial-lateral sway, ellipse area). Pain levels were reported using a Visual Analog Scale.

Results

The CAI ankles exhibited significantly lower ankle IMS in all muscle groups compared to the asymptomatic ankles (p < 0.001). Additionally, the CAI side showed increased postural sway and a larger ellipse area (p < 0.001), indicating reduced PC. Negative correlations were observed between ankle IMS and PC parameters on the CAI side, with dorsiflexor strength showing correlations ranging from -0.423 to -0.387, plantar flexor strength ranging from -0.423 to -0.371, invertor strength ranging from -0.412 to -0.238, and evertor strength ranging from -0.451 to -0.365 (p < 0.001). Mediation analysis revealed that pain played a significant mediating role in connecting ankle IMS and PC parameters among individuals with CAI, with statistical significance (p < 0.05).

Conclusions

Individuals with CAI exhibit weaker ankle IMS and diminished PC in comparison to their healthy side. Moreover, pain was identified as a mediator in the relationship between ankle IMS and PC in CAI. These findings underscore the importance of addressing both ankle IMS and pain in the rehabilitation and management of CAI.

Soleus arthrogenic muscle inhibition following acute lateral ankle sprain correlates with symptoms and ankle disability but not with postural control

BACKGROUND

Acute lateral ankle sprains (ALAS) are associated with long-term impairments and instability tied to altered neural excitability. Arthrogenic muscle inhibition (AMI) has been observed in this population; however, relationships with injury-related impairments are unclear, potentially due to the resting, prone position in which AMI is typically measured. Assessing AMI during bipedal stance may provide a better understanding of this relationship.

METHODS

AMI was assessed in 38 young adults (19 ALAS within 72 h of injury: 10 males, 21.4 ± 2.7 years; 19 healthy controls: 10 males, 21.9 ± 2.2 years; mean ± SD) using the Hoffmann reflex during bipedal stance. Electrical stimulation was administered to identify the maximal H-reflex (Hmax) and maximal motor response (Mmax) from the soleus, fibularis longus, and tibialis anterior muscles. The primary outcome measure was the Hmax/Mmax ratio. Secondary outcomes included acute symptoms (pain and swelling), postural control during bipedal stance, and self-reported function.

RESULTS

No significant group-by-limb interactions were observed for any muscle. However, a significant group main effect was observed in the soleus muscle, F1,35 = 6.82, p = 0.013, indicating significantly lower Hmax/Mmax ratios following ALAS (0.38 ± 0.20) compared to healthy controls (0.53 ± 0.16). Furthermore, lower Hmax/Mmax ratios in the soleus significantly correlated with acute symptoms and self-reported function but not with postural control.

CONCLUSION

This study supports previous evidence of AMI in patients with ALAS, providing insight into neurophysiologic impacts of musculoskeletal injury. Our results suggest that assessing AMI in a standing position following acute injury may provide valuable insight into how AMI develops and guide potential therapeutic options to curb and offset the formation of joint instability.

Pain alleviation improves balance control and muscular coordination of lower limbs in patients with chronic ankle instability during sinusoidal perturbations

BACKGROUND

It is well established that individuals with chronic ankle instability manifest deficits in balance control and muscle activation. Given the prevalence of pain as a prominent symptom in this population, there is a need for in-depth investigation of its role in contributing to these impairments.

METHODS

A Stewart platform was used to generate translational sinusoidal perturbations in the antero-posterior direction. Eighteen individuals with chronic ankle instability and concurrent ankle pain were recruited. They were instructed to assume a central stance on the support surface with open eyes both before and 30 min after local analgesia. Data of center of pressure and electromyography of the tibialis anterior and medial gastrocnemius were recorded. Statistical analysis was performed to make comparisons pre- and post-analgesia using two-tailed paired t-test for the continuous variables.

FINDINGS

Pain intensity was significantly decreased after local anesthetic injections. Antero-posterior center of pressure parameters significantly decreased following the injection. Also, there was an increase in the regularity of the center of pressure pattern. The electromyographic pattern of the tibialis anterior and medial gastrocnemius exhibited various activation patterns. After pain alleviation, the characteristic electromyographic response of the tibialis anterior and medial gastrocnemius was reciprocal contraction and relaxation that corresponded with the sinusoidal pattern of the perturbations.

INTERPRETATION

Individuals who had chronic ankle instability and ankle pain demonstrated impaired balance control during sinusoidal perturbations. Mitigating pain improved their balance performance, evident in the center of pressure pattern and the coordination of lower limb muscles.

Relationship between ankle pain, range of motion, strength and balance in individuals with functional ankle instability: a cross-sectional study

BACKGROUND

About 15-60% of individuals with ankle sprains may develop functional ankle instability (FAI), which is characterised by ankle pain, decreased muscle strength, limited range of motion, and impaired balance, causing a decline in social activity and quality of life. However, the relationship between those characters is still unclear. This study aimed to investigate whether a relationship existed between ankle pain, active range of motion (AROM), strength and balance and if ankle pain, AROM and strength can predict balance in individuals with FAI.

METHODS

Seventy-seven subjects (46 males; 31 females) with unilateral FAI participated in this study. Ankle pain was measured by the visual analogue scale (VAS), ankle AROM was measured using a universal goniometer, ankle strength was measured using a handheld dynamometer, the static balance was measured by the Time in Balance Test (TBT) and the dynamic balance was measured by the modified Star Excursion Balance Test (mSEBT). Pearson product-moment correlations were used to determine the correlations between ankle pain, AROM, strength and balance. Multiple linear regressions were used to investigate if ankle pain, AROM and strength can predict balance in individuals with FAI.

RESULTS

VAS and AROM-plantarflexion predicted 25.6% of the TBT (f2 = 0.344, P < 0.001). AROM-dorsiflexion predicted 24.6% of the mSEBT-anterior reach (f2 = 0.326, P < 0.001). VAS, AROM-plantarflexion and strength-plantarflexion predicted 33.5% of the mSEBT-posteromedial reach (f2 = 0.504, P < 0.001). AROM-plantarflexion and strength-plantarflexion predicted 28.2% of the mSEBT-posterolateral reach (f2 = 0.393, P < 0.001).

CONCLUSION

This study shows that ankle plantarflexion strength, AROM of dorsiflexion and plantarflexion and pain are predictors of balance in individuals with FAI. These factors could be considered in the rehabilitation of FAI.

TRIAL REGISTRATION

Trial registration number: ChiCTR2200063532.

Factors associated with persistent pain in college athletes with a history of lateral ankle sprain

OBJECTIVES

To determine the factors associated with and prevalence of persistent pain in college athletes with chronic ankle instability (CAI) and with previous lateral ankle sprain (LAS) without CAI.

DESIGN

Cross-Sectional Study.

SETTING

Online survey at one university.

PARTICIPANTS

Of the 385 respondents surveyed online, 140 were identified as having experienced at least one LAS (CAI group: 69, coper group: 24, LAS group not classified as either: 47).

MAIN OUTCOME MEASURES

Factors associated with the presence of pain during activities of daily living (ADL) and sports were identified using multivariate logistic regression analyses. Independent variables were demographics, injury characteristics, the Identification of Functional Ankle Instability (IdFAI) score, the Foot and Ankle Ability Measure Sports (FAAM-Sports) and ADL subscales, and the Tampa Scale for Kinesiophobia-11 score.

RESULTS

The prevalence of pain during ADL and sports in the three groups was 16.7%-42.0% and 33.3%-56.5%, respectively. FAAM-Sports and IdFAI score were significantly associated with pain during ADL and sports in the CAI group (odd ratio: 0.923 and 1.145), respectively. No significant pain-related factors were found in the coper and LAS groups.

CONCLUSIONS

Lower self-reported function and greater perceived ankle instability may be important factors in pain management in athletes with CAI.

Kinesiophobia, self-reported ankle function, and sex are associated with perceived ankle instability in college club sports athletes with chronic ankle instability

OBJECTIVE

To investigate the association between sex, self-reported ankle function, pain intensity, kinesiophobia, and perceived ankle instability in athletes with chronic ankle instability (CAI).

DESIGN

Cross-Sectional Study.

SETTING

University.

PARTICIPANTS

College club sports athletes with CAI (n = 42).

MAIN OUTCOME MEASURES

Relationships with the Cumberland Ankle Instability Tool (CAIT) score and the Tampa Scale for Kinesiophobia-11 (TSK-11), the Foot and Ankle Ability Measure (FAAM), sex (0: male, 1: female), and ankle pain intensity by the Numeric Rating Scale were explored with multiple regression analysis.

RESULTS

The regression model explained 50.3% of the variance of the CAIT score (P < 0.001), and the TSK-11 score (B = -0.382, P = 0.002), the FAAM sports subscale score (B = 0.122, P = 0.038), and sex (B = -2.646, P = 0.031) were significant independent variables for the CAIT score (P < 0.001), while pain intensity was not significant (B = -0.182, P = 0.504). These results indicated that higher TSK-11 score, lower FAAM sports subscale score, and being female were related to lower CAIT score.

CONCLUSIONS

Kinesiophobia related to perceived instability along with self-reported function and sex in athletes with CAI. Clinicians should assess the psychological aspects of athletes with CAI.

Neuroplasticity of pain processing and motor control in CAI patients: A UK Biobank study with clinical validation

Background

Pain plays an important role in chronic ankle instability (CAI), and prolonged pain may be associated with ankle dysfunction and abnormal neuroplasticity.

Purpose

To investigate the differences in resting-state functional connectivity among the pain-related brain regions and the ankle motor-related brain regions between healthy controls and patients with CAI, and explore the relationship between patients' motor function and pain.

Study design

A cross-database, cross-sectional study.

Methods

This study included a UK Biobank dataset of 28 patients with ankle pain and 109 healthy controls and a validation dataset of 15 patients with CAI and 15 healthy controls. All participants underwent resting-state functional magnetic resonance imaging scanning, and the functional connectivity (FC) among the pain-related brain regions and the ankle motor-related brain regions were calculated and compared between groups. The correlations between the potentially different functional connectivity and the clinical questionnaires were also explored in patients with CAI.

Results

The functional connection between the cingulate motor area and insula significantly differed between groups in both the UK Biobank (p = 0.005) and clinical validation dataset (p = 0.049), which was also significantly correlated with Tegner scores (r = 0.532, p = 0.041) in patients with CAI.

Conclusion

A reduced functional connection between the cingulate motor area and the insula was present in patients with CAI, which was also directly correlated with reduction in the level of patient physical activity.

The influence of local pain on balance control in patients with chronic ankle instability

Background

Local pain around the ankle joint is a common symptom in patients with chronic ankle instability (CAI). However, whether the local pain would impose any influence on the balance control performance of CAI patients is still unknown.

Methods

A total of twenty-six subjects were recruited and divided into the following two groups: pain-free CAI (group A) and pain-present CAI (group B). Subjects in both groups received two independent tests: the star excursion balance test and the single-leg stance test, in order to reflect their balance control ability more accurately.

Results

Compared with group A, the group B showed significantly more episodes of the history of sprains, decreased ankle maximum plantarflexion angle, and lower Cumberland scores (all p < 0.05). In the star excursion balance test, group B demonstrated a significantly reduced anterior reach distance than group A (p < 0.05). During the single leg stance test, group B showed a significant increase in the magnitude of electromyographic signals both in peroneus longus and soleus muscles than group A (each p < 0.05). Additionally, group B had a significantly more anterolaterally positioned plantar center of pressure than group A (p < 0.05).

Conclusion

CAI patients with local pain around the ankle joint had more episodes of sprains and lower functional scores when compared to those without pain. The balance control performance was also worse in the pain-present CAI patients than those without pain.

Perceived Instability, Pain, and Psychological Factors for Prediction of Function and Disability in Individuals With Chronic Ankle Instability

CONTEXT

Chronic ankle instability (CAI) is associated with residual instability, pain, decreased function, and increased disablement. Injury-related fear has been associated with CAI, although its relationship to other impairments is unclear. The fear-avoidance model is a theoretical framework hypothesizing a relationship among pain catastrophizing, injury-related fear, chronic pain, and disability. It has been useful in understanding fear's influence in other musculoskeletal conditions but has yet to be studied in those with CAI.

OBJECTIVE

To explore relationships among instability, pain catastrophizing, injury-related fear, pain, ankle function, and global disability in individuals with CAI.

DESIGN

Cross-sectional study.

SETTING

Anonymous online survey.

PATIENTS OR OTHER PARTICIPANTS

A total of 259 people, recruited via email and social media, with a history of ankle sprain completed the survey; of those, 126 participants (age = 32.69 ± 4.38 years, females = 84.92%, highly active = 73.81%) were identified as having CAI and were included in the analysis.

MAIN OUTCOME MEASURE(S)

Demographics of gender identity, age, and physical activity level were recorded. Assessments used were the Identification of Functional Ankle Instability questionnaire (instability), the Pain Catastrophizing Scale (pain catastrophizing), the Tampa Scale of Kinesiophobia-11 (injury-related fear), a numeric pain rating scale and activity-based question (pain presence), the Quick Foot and Ankle Ability Measure (ankle function), and the modified Disablement in the Physically Active Scale (disability). Relationships among variables were explored through correlation and regression analyses.

RESULTS

After we controlled for instability and pain, pain catastrophizing and injury-related fear were significantly related to function and disability ratings in individuals with CAI. Together, the variables predicted 48.7% (P < .001) of the variance in function and 44.2% (P < .001) of the variance in disability.

CONCLUSIONS

Greater instability, pain catastrophizing, injury-related fear, and pain predicted decreased function and greater disability in those with CAI. These findings are consistent with the hypothesized relationships in the fear-avoidance model, although further investigation is needed to determine causality of these factors in the development of CAI.

Prevalence of ankle instability in performers of Chinese classical dance: a cross-sectional study of 105 Chinese dancers

Objectives

Foot and ankle injuries are commonly seen in dancers, yet limited studies exist on the injury prevalence of performers of Chinese classical dance. This study aims to determine and assess the prevalence of chronic ankle instability (CAI) in Chinese dancers and correlate the impact of CAI with foot function.

Methods

This is a cross-sectional study of 105 Chinese dancers. CAI was assessed using the Cumberland Ankle Instability Tool and foot function via the Foot and Ankle Outcome Score (FAOS). Both self-reported assessment tools were distributed online between January and February 2021. Subjects were divided into CAI and healthy groups to observe any correlations in demographics, training hours and foot function.

Results

CAI was seen in 28% of Chinese dancers, with most being unilateral instability. The number of training hours, level of expertise, occupation, gender and age showed no statistical significance with CAI. The FAOS showed that subjects with CAI had significantly greater pain and poorer quality of life.

Discussion and conclusion

CAI is a problem affecting 28% of performers of Chinese dance. Future research should investigate the ankle biomechanics in Chinese dance and specific risk factors for CAI to formulate strategies to prevent ankle injuries in Chinese dancers.

Differences in health-related quality of life among patients after ankle injury

Ankle sprains are the most common injuries sustained in the physically active, often associated with pain and functional limitations long after initial recovery. In recent years, the impact of ankle sprains on general health and health-related quality of life (HRQoL) has been noted in athletes, but is not well-documented in the general population. We examined differences in HRQoL and general health between individuals with ankle sprain history and healthy controls. Those with ankle sprain reported significantly higher body mass index and general body pain, and lower SF-8 physical component scores than healthy controls. Additionally, there is some indication that physical activity is lower in those with ankle sprain history. This is an important step in illustrating the adverse sequelae of ankle sprains on population health and HRQoL.

Not Only in Sensorimotor Network: Local and Distant Cerebral Inherent Activity of Chronic Ankle Instability—A Resting-State fMRI Study

Background

Increasing evidence has proved that chronic ankle instability (CAI) is highly related to the central nervous system (CNS). However, it is still unclear about the inherent cerebral activity among the CAI patients.

Purpose

To investigate the differences of intrinsic functional cerebral activity between the CAI patients and healthy controls (HCs) and further explore its correlation with clinical measurement in CAI patients.

Materials and Methods

A total of 25 CAI patients and 39 HCs were enrolled in this study. Resting-state functional magnetic resonance imaging (rs-fMRI) was used to detect spontaneous cerebral activity. The metrics of amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), and regional homogeneity (ReHo) of the two groups were compared by two-sample t-test. The brain regions that demonstrated altered functional metrics were selected as the regions of interest (ROIs). The functional connectivity (FC) was analyzed based on the ROIs. The Spearman correlation was calculated between rs-fMRI metrics and clinical scale scores.

Results

Compared with HCs, CAI patients showed higher ALFF and ReHo values in the right postcentral gyrus, the right precentral gyrus, and the right middle frontal gyrus, while lower fALFF values in the orbital-frontal cortex (OFC, p &lt; 0.01 after correction). Increasing FC between the right precentral gyrus and the right postcentral gyrus while decreasing FC between the right precentral gyrus and the anterior cingulum cortex (ACC), the right middle frontal gyrus and the left middle temporal gyrus, and the OFC and left inferior parietal lobule (IPL) was observed. In addition, in the CAI group, the ReHo value negatively correlated with the Cumberland Ankle Instability Tool score in the right middle frontal gyrus (r = −0.52, p = 0.007).

Conclusion

The CAI patients exhibited enhanced and more coherent regional inherent neuronal activity within the sensorimotor network while lower regional inherent activity in pain/emotion modulation related region. In addition, the information exchanges were stronger within the sensorimotor network while weaker between distant interhemispheric regions. Besides, the increased inherent activity in the right middle frontal gyrus was related to clinical severity. These findings may provide insights into the pathophysiological alteration in CNS among CAI patients.

Effect of Four Weeks of Home-Based Balance Training on the Performance in Individuals with Functional Ankle Instability: A Remote Online Study

The purpose of the current study is to evaluate the effect of 4 weeks of home-based balance training (HBBT) on the performance of individuals with functional ankle instability (FAI) in daily activities and sports. Thirty college students diagnosed with FAI and with a mean weight of 79.8 ± 3.4 kg, height of 182.5 ± 5.1 cm, age of 23.5 ± 1.2 years, and instability score of 20 ± 2.3 were selected to participate in this study and were randomly divided by computer-generated methods into two groups: the HBBT group and the control group (CG), each consisting of 15 subjects. The HBBT group performed the program at home for 4 weeks, while the CG was non-exercise. Before and after the 4 weeks of exercise program, a form containing the foot and ankle ability measure for daily activities and sports was completed by the individuals. For data analysis, intra- and inter-group comparisons were performed using paired and independent sample t-tests, respectively, at a significance level of p ≤ 0.05. The results showed that 4 weeks of progressive HBBT were sufficient to significantly improve the measurement of the ability of ankle and foot function in individuals with FAI, even with a total volume of only 60 min per week. Accordingly, it is suggested that individuals with FAI can benefit from short-term HBBT programs, which are simple yet powerful enough to promote improvements in daily activities.

In Vivo Foot and Ankle Kinematics During Activities Measured by Using a Dual Fluoroscopic Imaging System: A Narrative Review

Foot and ankle joints are complicated anatomical structures that combine the tibiotalar and subtalar joints. They play an extremely important role in walking, running, jumping and other dynamic activities of the human body. The in vivo kinematic analysis of the foot and ankle helps deeply understand the movement characteristics of these structures, as well as identify abnormal joint movements and treat related diseases. However, the technical deficiencies of traditional medical imaging methods limit studies on in vivo foot and ankle biomechanics. During the last decade, the dual fluoroscopic imaging system (DFIS) has enabled the accurate and noninvasive measurements of the dynamic and static activities in the joints of the body. Thus, this method can be utilised to quantify the movement in the single bones of the foot and ankle and analyse different morphological joints and complex bone positions and movement patterns within these organs. Moreover, it has been widely used in the field of image diagnosis and clinical biomechanics evaluation. The integration of existing single DFIS studies has great methodological reference value for future research on the foot and ankle. Therefore, this review evaluated existing studies that applied DFIS to measure the in vivo kinematics of the foot and ankle during various activities in healthy and pathologic populations. The difference between DFIS and traditional biomechanical measurement methods was shown. The advantages and shortcomings of DFIS in practical application were further elucidated, and effective theoretical support and constructive research direction for future studies on the human foot and ankle were provided.

Risk Factors of Atrial Arrhythmia in Patients With Liver Cirrhosis: A Retrospective Study

Background and Objectives: Liver cirrhosis is known to be associated with atrial arrhythmia. However, the risk factors for atrial arrhythmia in patients with liver cirrhosis remain unclear. This retrospective study aimed to investigate the risk factors for atrial arrhythmia in patients with liver cirrhosis. Methods: In the present study, we collected data from 135 patients with liver cirrhosis who were admitted to the Department of Gastroenterology at Shanghai Tongji Hospital. We examined the clinical information recorded, with the aim of identifying the risk factors for atrial arrhythmia in patients with liver cirrhosis. Multiple logistic regression analysis was used to screen for significant factors differentiating liver cirrhosis patients with atrial arrhythmia from those without atrial arrhythmia. Results: The data showed that there were seven significantly different factors that distinguished the group with atrial arrhythmia from the group without atrial arrhythmia. The seven factors were age, white blood cell count (WBC), albumin (ALB), serum Na⁺, B-type natriuretic peptide (BNP), ascites, and Child-Pugh score. The results of multivariate logistic regression analysis suggested that age (β = 0.094, OR = 1.098, 95% CI 1.039-1.161, P = 0.001) and ascites (β =1.354, OR = 3.874, 95% CI 1.202-12.483, P = 0.023) were significantly associated with atrial arrhythmia. Conclusion: In the present study, age and ascites were confirmed to be risk factors associated with atrial arrhythmia in patients with liver cirrhosis.

Ankle Stability and Movement Coordination Impairments: Lateral Ankle Ligament Sprains Revision 2021

This revised clinical practice guideline (CPG) addresses the distinct but related lower extremity impairments of those with a first-time lateral ankle sprain (LAS) and those with chronic ankle instability (CAI). Depending on many factors, impairments may continue following injury. While most individuals experience resolution of symptoms, complaints of instability may continue and are defined as CAI. The aims of the revision were to provide a concise summary of the contemporary evidence since publication of the original guideline and to develop new recommendations or revise previously published recommendations to support evidence-based practice. J Orthop Sports Phys Ther 2021;51(4):CPG1-CPG80. doi:10.2519/jospt.2021.0302.

Bibliometric Analysis of Research on the Comorbidity of Pain and Inflammation

Objectives

To provide a comprehensive review on the global scientific research status of comorbid pain and inflammation from 1981 to 2019 and capture its subsequent development trends. Data Sources. The primary database chosen to collect publications on comorbid pain and inflammation research from 1981 to 2019 was the Web of Science (WOS). Core of the search strategy was the key word “pain” and the key word “inflammation” in the medical subject headings' major field. Study Selection. All articles retrieved were included in the bibliometric analysis. Data Extraction. We used CiteSpace to analyze publication outputs, subject categories, distribution by country/institution/journal, and other types of information. Then, knowledge base, hot issues, and future development directions were explained. Data Synthesis. A total of 2887 papers met the inclusion criteria in our research. Linear regression analysis results showed that the publications of studies of comorbid pain and inflammation significantly increased (P < 0.001) and have grown about 192 times in 40 years. The countries with the most outputs were the USA (886 publications), China (375 publications), and England (236 publications). Besides, Harvard University was the most prolific institution with 730 publications and 6646 citations. In accordance with the subject categories of WOS, neurosciences (31.832%), pharmacology/pharmacy (18.427%), and clinical neurology (15.206%) were the main research areas of these 2887 papers.

Conclusions

The current study reveals that research on comorbid pain and inflammation has gradually become more extensive worldwide since 1981, and neuropathic pain was the most popular study type. Most of our research output in this field came from countries in Europe and North America, although some Asian countries showed promising performance.

Bibliometric Study of Pain after Spinal Cord Injury

Background

The prevalence of comorbid pain after spinal cord injury (SCI) is relatively high in clinical observations and has continued to increase over time. Neuropathic pain (70.14%) is the most popular subject in academic journals after SCI. However, studies that used the bibliometric method to analyze comorbid pain after SCI are still lacking. This study is aimed at combining and integrating acquired information to analyze the global trends of research on the comorbidity of pain after SCI in the last three decades (1990–2019).

Methods

Systematic works of literature published from 1990 to 2019 were obtained from the Web of Science Core Collection. CiteSpace software was used to analyze the relationship of publication year with the country, institution, journals, authors, references, and keywords. The regression analysis is used to evaluate the percentage of the category increase or decrease over time significantly. IBM SPSS Statistics was used in the statistical analysis.

Results

A total of 730 publications were included in the analysis. A remarkable increase in the number of publications was observed in the study period (P < 0.05). A total of 202 academic journals focused on the categories of clinical neurology, neurosciences, and rehabilitation, and the annual growth rate of articles in these three categories was statistically significant (P < 0.05). The USA (356, 48.77%) and the University of Miami (64, 8.77%) were the country and institution with the highest number of publications, respectively. Spinal Cord, which was the main journal for research on pain after SCI, had the most publications (88, 12.05%). Burst keywords showed that the individual, inflammation, and central sensitization with pain after SCI are the research development trends and focus in this research field.

Conclusions

Overall, this study provides the latest research direction for pain after SCI. This historical overview of research into pain after SCI will be a useful basis for further research into development trends, focus issues, cooperators, and cooperative institutions.