DOI: 10.20986/resed.2018.3679/2018
REVIEW
Influence of psychosocial factors on the experience of musculoskeletal pain: a literature review
I. Cuyul Vásquez1 y F. Araya-Quintanilla2,3
1Facultad de Ciencias de la Salud. Departamento de Procesos Terapéuticos. Universidad Católica de Temuco, Chile. 2Facultad de Ciencias de la Salud. Universidad Gabriela Mistral. Santiago. Chile. 3Facultad de Ciencias de la Salud. Universidad de las Américas. Santiago, Chile
Received: 16-04-2018
Accepted: 18-04-2018
Correspondence: Felipe Araya-Quintanilla
fandres.kine@gmail.com
ABSTRACT
Musculoskeletal pain is a health problem that affects approximately 33 % of the adult population, of which 56 % corresponds to elderly people and 35% to people of working age. Some epidemiological investigations have shown that there are certain groups of people within the population most likely to develop chronic musculoskeletal pain, these studies have allowed to identify different weaknesses and needs in the interventions of health professionals in this problem. The data have shown that the prevalence of pain is higher in women, smokers, with incomplete education, with psychological or social risk, in this way the evidence has removed attention to the nociception of body structures as the only causal factor of pain musculoskeletal This has forced researchers to explore the influence of psychosocial factors in the experience of musculoskeletal pain, consider the integration of various factors and mechanisms to explain the development of the painful experience. The objective of this review is to describe the psychosocial factors that influence the experience of musculoskeletal pain in order to relate them to contemporary neuroscientific models
Key words: Muscle skeletal pain, psychosocial factors, pain, literature review.
RESUMEN
El dolor musculoesquelético es un problema sanitario que afecta aproximadamente a un 33 % de la población adulta, del cual un 56 % corresponde a personas adultos mayores y un 35 % a personas en edad laboral. Algunas investigaciones epidemiológicas han demostrado que existen ciertos grupos de personas dentro de la población más propensos a desarrollar dolor crónico musculoesquelético; estos estudios han permitido identificar diferentes debilidades y necesidades en las intervenciones de los profesionales de la salud en esta problemática. Los datos han demostrado que la prevalencia del dolor es mayor en mujeres, personas fumadoras, con educación incompleta, con riesgo psicológico o social, de esta manera la evidencia le ha quitado la atención a la nocicepción de las estructuras corporales como único factor causal de dolor musculoesquelético. Esto ha obligado a los investigadores a explorar la influencia de los factores psicosociales en la experiencia de dolor musculoesquelético, considerar la integración de diversos factores y mecanismos para provocar explicar el desarrollo de la experiencia dolorosa. La presente revisión tiene como objetivo describir los factores psicosociales que influyen en la experiencia de dolor musculoesquelético para relacionarlos con los modelos neurocientíficos contemporáneos.
Palabras clave: Dolor musculoesquelético, factores psicosociales, dolor, revisión bibliográfica.
INTRODUCTION
Musculoskeletal pain is a health problem affecting approximately 33 % of the adult population. A total of 56 % of the affected subjects are elderly people and 35% are people at working age (1). Some epidemiological studies have shown that certain groups of people within the population are most likely to develop chronic musculoskeletal pain (2,3). These studies have contributed to the identification of different weaknesses and needs of the interventions of healthcare professionals regarding this problem. Data have shown that the prevalence of pain is higher in women (3), smokers (4), people with incomplete education (5) or, at psychological or social risk (6). In this way, the evidence has removed the focus on the nociception of body structures as the only causal factor of musculoskeletal pain (7).
It has been mentioned that some healthcare professionals consider nociception and pain as synonyms (8). Because of this, society in general has developed beliefs based on an erroneous model of knowledge (7). In these models, the cause of musculoskeletal pain is related to a damaged tissue that sends painful signals to the central nervous system for its perception (8). However, there is no such relationship between pain and nociception, nor between pain and tissue damage (9). Several Systematic Reviews (RS) have demystified these knowledge models. Van Tulder et al. (10) included 35 observational studies seeking to identify the relationship between imaging findings and low back pain in their SR. The authors concluded that no solid evidence confirming a relationship between pain and imaging findings in subjects with low back pain is available. Brinjikji et al. (11) included 13 studies that evaluated the imaging findings and disc degeneration in asymptomatic subjects. These authors concluded that no relationship between the degree of disc degeneration and the intensity of pain in 3110 asymptomatic patients was present. Christensen et al. (12) did not find any causal relationship between postural alterations and painful symptoms when evaluated 54 studies. Therefore, current research has a neuroscience-oriented approach to reconceptualize pain and answer several questions to improve the understanding of this problem (13).
Currently, pain is defined as a complex interaction of homeostatic systems in response to an identified threat (14); in this way, pain should be considered a process integrating sensory, cognitive and/or emotional information coming from real or potential threats (15). This process of evaluation of the threat is carried out by a set of cortical and subcortical structures denominated pain neuromatrix (16). In functional terms, the neuromatrix of people with acute or chronic pain is composed of the bilateral secondary and primary contralateral somatosensory cortex, insular cortex, cerebellum, basal ganglia, thalamus and the anterior cingulate cortex (17). Therefore, beliefs and emotions are capable of activating the neuromatrix, provoking and even perpetuating pain without the need for nociception (18). This has forced researchers to explore the influence of psychosocial factors on the experience of musculoskeletal pain, to consider the integration of various factors and mechanisms to explain the development of the painful experience (19).
The objective of this review is to describe the psychosocial factors influencing the experience of musculoskeletal pain in order to relate them to contemporary neuroscience models.
MATERIAL AND METHODS
An electronic search was performed in the following databases: Medline, PEDro, Central, SPORTDiscus, the search terms were: Musculoskeletal Pain [Mesh], Chronic Pain [Mesh], Social Determinants of Health [Mesh], Psychology [Mesh], Pain. Articles published until January 31, 2018 in English and Spanish were selected. For the selection of articles, articles were first filtered by title and abstract, and then articles were filtered by full text. A total of 64 studies were analyzed to conduct this review.
PSYCHOSOCIAL FACTORS OF THE EXPERIENCE OF MUSCULOSKELETAL PAIN
Cognitive-affective factors
Research regarding cognitive-affective factors in people with musculoskeletal pain has grown exponentially in recent years (20). In general, people with emotional or behavioral problems, excessive alcohol consumption or sleep disorders have shown to be more likely to develop musculoskeletal pain in the medium or long term (21,22). Generally, people with cognitive-affective disorders describe pain in more than one part of their bodies, of greater intensity and functional restriction in their daily activities (23-25). From this point of view, negative emotions in people with pain, such as shame, guilt or fear of negative evaluation of their peers have been shown to be predictors of high pain indices (26).
Catastrophizing
Catastrophizing is the tendency to generate irrationally negative predictions related to a perceived threat (20). Several research studies have confirmed the positive correlation between catastrophizing, pain intensity and degree of perceived disability (25,27,28). Slepian et al. (29) showed that the presence of catastrophizing significantly reduces the effectiveness of physical therapy when this aspect is not considered during rehabilitation, because catastrophizing has a significant impact on cortical motor activity and sensory integration areas, which would limit the outcomes of approaches that include physical exercise (30). Furthermore, Vargas Prada et al. (31) conducted a study including 971 patients with chronic musculoskeletal pain, these authors showed that the onset and transition of disabling musculoskeletal pain was mediated by high levels of catastrophizing (31). Lee et al. (32) studying experimental pain could identify the role of catastrophizing in the initial stages of an injury. For this, they applied an acid solution in the tibialis anterior in 189 asymptomatic subjects, this study evidenced that people with high negative emotionality showed higher local pain, mechanical hyperalgesia and the likelihood of experiencing referred pain compared to a group with less negative emotionality. Niederstrasser et al. (33) showed that high levels of catastrophizing and fear of pain predict an increase in the response to a non-harmful stimulus. This study was conducted in 82 asymptomatic university subjects using a protocol for the induction of unilateral muscle pain (33). Other studies have shown that catastrophizing accompanied by fear of pain or depressive symptoms increase the risk of pain in areas distant from the origin of the injury, persistency and impair function after a musculoskeletal injury (34-36).
Depression and anxiety
The relationship between pain and depression has been thoroughly studied. From this perspective, a certain linear relationship has been found between depressive symptoms, disability and pain, which is translated into a lower quality of life (37, 38). Depression has been identified as a predictor of chronic pain in the wrists, hands, shoulders and cervical spine (39-41). Kim et al. (42) showed in a study conducted in 218 subjects with neck pain, that 53.7% developed mild-severe insomnia and depression was the strongest predictor of this insomnia. Another study in older adults with dementia showed that depression was related to the intensity of chronic musculoskeletal pain (43). Anxiety in a very common condition in people with musculoskeletal disorders. Current studies have showed some correlation between pain intensity, degree of disability and anxiety (23, 43). An observational study showed that 50% of workers with musculoskeletal pain associated with some degree of disability have generalized anxiety, which decreases significantly when interventions are conducted to improve the degree of disability (44). Losa et al. (45) showed in a study conducted in 421 workers that young and single women tend to have higher levels of pain and anxiety than men.
Neuroticism and perception of stress
Studies related to neuroticism are scarce. Wong et al. (46) showed in 401 people with chronic musculoskeletal pain that patients with higher levels of neuroticism and negative affectivity have higher levels of catastrophizing regarding pain. Moreover, Molina et al. (47) showed that adolescents with musculoskeletal pain show higher perceived stress than healthy controls. Another study conducted in 422 adolescents identified that 22% of the population reported moderate to severe stress, 79% of them attributed it to the presence of pain; therefore, perceived stress was associated with more reports on pain, intensity and number of affected sites (48). However, the presence of adverse events in life is a predictor of chronic pain, regardless of the function of biological stress systems, socio-demographic factors, lifestyles, chronic diseases, depression and/or anxiety (49).
In a cross-sectional study conducted in 1646 people with or without musculoskeletal pain, Generaal et al. (50) showed that high levels of stress correlate positively with the presence and severity of chronic pain. Sommer et al. (51) confirmed the positive correlation between pain and work stress in men. Nevertheless, Bonzini et al. (52) after researching 305 nurses, the authors pointed out that stress does not seem to be a causal factor of musculoskeletal pain, but rather a consequence of the pain. From a neuroendocrine point of view, dysfunction of the hypothalamic-pituitary axis and immune system were not associated with the onset of musculoskeletal pain in a sample of 2039 subjects at a 6-year follow-up (49). Furthermore, Paanamem et al. (53) showed an association between hypoactivity of the hypothalamic-pituitary-adrenal axis in stressful situations and the presence-severity of pain problems 4 years later.
Hypervigilance and kinesiophobia
Research on hypervigilance and pain relationship is scarce. Wong et al. (54) researched 401 people with chronic musculoskeletal pain, and showed that the fear of pain is conditioned by hypervigilance, which increases levels of anxiety and catastrophizing. With regard to fear of movement and kinesiophobia, Sell et al. (55) mention that there is a positive association between kinesiophobia and disability. Gil-Martínez et al. (56) found a moderate correlation between craniofacial and cervical pain and the degree of disability.
From another perspective, it has been shown an inverse relationship between the degree of understanding of neurophysiology of pain and the levels of kinesiophobia in people with chronic musculoskeletal pain. Intervention through therapeutic education has shown a positive influence on kinesiophobia and fear-avoidance beliefs (57).
Social factors
Unlike cognitive-affective factors, the study of social factors of pain is more recent. There is a predominance of research linked to work and its environment.
Interpersonal relationships and social support
In relation to this issue, poor social support of supervisors at work has shown to be associated with higher rates of musculoskeletal pain (58-60), especially in women (61). However, social support at work and economic independence are protective factors in women with depression (62). Tang et al. (63) showed in 6676 older adults that physical limitation and the reduction of social participation have been correlated with significant increases in pain and insomnia during 3 years of follow-up. Similarly, Wilkie et al. (64) showed that the pain-depression relationship is also negatively influenced by the reduction of social participation in older adults.
Family conflicts and gender inequality have been strongly associated with the presence of musculoskeletal pain in workers of different healthcare services (65, 66). According to Boonstra et al. (67), people with higher levels of pain, usually dissatisfied with their self-care ability and work situation, show a tendency to evaluate in a positive manner the relationship with partners, family life and contact with friends. Consequently, family conflicts caused by work seem not to influence the experience of pain. However, emotional exhaustion at work seems to be a more important mediator in pain levels (68).
Cultural factors
Research on cultural factors is scarce. Dionne et al. (69) conducted a cross-sectional study with 14,249 subjects; this study has shown that the prevalence of severe pain in shoulder-arm and knee-leg is significantly lower in the groups of higher socioeconomic status. Moreover, Mehlum et al. showed that the prevalence of pain is higher in women of working age with low socioeconomic status (70).
Work history
From this perspective, the perception of heavy work is a predictor of pain in back, upper extremity (71) and lower extremities (72). Heavy work at home, excessive control at work and imbalance between work-family lives associated with work with high physical demands have proven to be predictors of various musculoskeletal disorders (73, 74). Some characteristics of work such as precariousness (41), high pressure (61), inequality in the degree of effort-reward (75), perception of lack of staff (76), security problems (77), labor organization (78) and long work days, as well as poor social support have been correlated positively with different types of musculoskeletal pain disorders (79). Furthermore, heavier physical workloads, especially in groups of workers with low levels of schooling, show higher rates of musculoskeletal pain (80). Similarly, workers with shifts have higher somatization rates than those who have free weekends (59); it should be noted that, in this sense, there are certain groups of workers that are more vulnerable to somatization (81). In addition, personal factors, such as low job satisfaction, poor teamwork capacity (82) and beliefs that work can be a significant risk factor, have been positively correlated with the number of pain problems (77). In contrast, people presenting musculoskeletal pain and continue working show significantly lower levels of fear, avoidance, catastrophizing, perception of overload, greater acceptance and self-efficacy compared to sick workers who are out of work while they recover (83).
DISCUSSION
The present literature review aimed to describe the evidence of psychosocial factors influencing the experience of musculoskeletal pain. Some of the results indicate that depression is an important predictor of musculoskeletal pain (39-41). This is consistent with the results obtained by Sertel et al. (84), Hirchins et al. (85) and Christensen et al. (86). A recent systematic review (87) showed that depression is a predictor of the development of chronic non-cancer pain in people over 18 years of age. The studies included in the present review show that catastrophizing and depression were the most studied cognitive-affective factors and these factors had the highest correlation with musculoskeletal pain (25, 27, 28, 31, 37, 38). Similar findings have been described in other review studies such as Ramond et al. (88), Somers et al. (89), Lewis et al. (90) and Phyomaung et al. (91), studies that justify that cognitive aspects are strongly associated with musculoskeletal pain; however, it has not yet been possible to study whether it is a potential risk factor for musculoskeletal pain.
Regarding gender, the female population of working age has a higher tendency to develop musculoskeletal pain (45, 70). This is consistent with the results obtained by Paksaichol et al. (92), who showed that the female sex and the previous history of discomfort in the neck are predictive factors of the development of non-specific cervical pain. Racine et al. (93) tried to identify psychosocial factors that could contribute to differences in pain sensitivity between men and women. Their results show that depression does not explain differences, however, past individual history impacts on the painful response in women more than in men.
Based on the above, clinical assessments of general health should consider the screening of depressive symptoms and adverse life events to identify early those people at risk of developing chronic pain. Regarding prevention, it is necessary to promote the development of healthy social relationships in the population at risk, because relationships with partners, family life and contact with friends seem to be protective factors.
Regarding social factors related to work history, the results of the systematic review conducted by Ariens et al. (94) point out that the perception of heavy work, excessive control during the workday, the imbalance between work-family life associated with work of high physical demands are predictors of the development of musculoskeletal pain (73,74). Moreover, poor social support at work, low job satisfaction, poor ability to work within teams and the perception of work as a risk factor have been positively associated with musculoskeletal pain (61,77). Therefore, from the labor point of view, it is necessary to monitor the physical effort of the working days and the possible intervention to the population with physical labor activities. In addition, it is important to consider the evaluation of the perception of heavy work, the degree of control the person is undergoing and the level of work developed in the home, due to the predictive capacity of these variables on musculoskeletal pain. It is relevant to consider that social support at work could be considered as a protective factor for musculoskeletal pain, especially in women (62). Therefore, interventions such as sponsorship or the creation of spaces for socialization at work could reduce the incidence of pain in this population. Other factors that could be considered protectors are high socioeconomic status (69) and economic independence (62).
Apparently, the perception of vulnerability or fragility related to health (95), the work (71, 72) or social (90) environment could determine a higher activity of the pain neuromatrix to the stimuli, which could increase the probabilities of developing musculoskeletal pain. This could be explained by a predominance of the perception of threat mediated by the cognitive and emotional dimensions of pain (15). The perception of the environment, the biological or psychological condition of a person has a preponderant role in the recovery of the person, therefore the healthcare team must be aware that the interventions should, in addition to seek biological changes, consider encouraging change in the perception of the reality of people. This highlights the importance of interventions on the biological dimension must be consistent with interventions on the psychosocial factors conducted by the entire healthcare team.
This review study has some limitations. First, the bias of individual studies was not evaluated by any scale, which makes it difficult to extract results for later applicability. In addition, there was no analysis of the results of the individual studies, so the scope of this review should be taken with caution.
Finally, it is important to consider that scientific and technological advances, changes in laws or public policies influence the psychosocial factors of the population in general. Therefore, when recognizing their significant in the musculoskeletal health, it is necessary to establish a periodic and systematic evaluation of cognitive-affective and social factors. Moreover, the development of qualitative research in the subject should be considered due to the role currently played by the massification of information on the cultural development of the population.
CONFLICTS OF INTEREST
The authors declare no potential conflicts of interest regarding the research, authorship and/or publishing of this manuscript.
FUNDING
The authors did not receive any financial support for the research, authorship and/or publishing of this manuscript.
BIBLIOGRAPHY