Link between psychosocial factors, perceived stress and musculoskeletal injuries
The effects of major efforts in the field of ergonomics to reduce the risk of musculosketal disorders (MSDs) tend to fall short of what might be expected, possibly due to the lack of attention to improving the psychosocial working environment and a lack of interventions at an organisational level as well as at an individual level. Interventions to improve working conditions and reduce stress could have a major impact on recovery from MSDs and days lost to sickness.
Possible mechanism behind MSDs and its links to stress
A new study in Sweden has examined the current knowledge base on psychosocial factors and the links to musculosketal disorders (MSDs) by examining 81 different studies on the subject. The link between an unfavourable psychosocial environment and the prevalence of MSDs is well established, with a number of studies demonstrating that high stress at work is connected to increased risk of developing a musculoskeletal disorder. It is however possible for an individual to work with a high level of stress and not develop any symptoms or diseases. The physiological reaction to stress seems to be connected to previous experiences and genetic factors. The reaction to stress also depends on psychosocial factors in the workplace. People who are subject to bullying or discrimination often suffer a prolonged stress reaction of both a physiological and a psychological nature.
There are several scientific models that aim to explain the prevalence of MSD, although research on the reasons why acute pain symptoms turn into a long-term medical condition is limited. There is no single unifying model, but one which has scientific support is the ‘Cinderella hypothesis’. This model theorises that long-term and continuous usage of a muscle ensures that part of it is constantly active, which over time can lead to metabolic disorders and an inflammatory condition. The link between MSDs and stress could also be that increased stress leads to increased muscle activity and the secretion of a stress hormone, which could in turn lead to MSDs. Other studies have found links between a lack of ‘muscle rest’ due to stress and symptoms in the neck/shoulder. In one study examined by the Swedish researchers, a computer user who had few opportunities to rest was shown to have an increased risk of MSD since the muscles had no time to relax and thus were constantly active. This activity in turn caused problems in the neck and shoulder.
Individual and organisational interventions
Interventions at the individual level should provide the individual with the required skill and energy necessary to strengthen and develop their own resources to better withstand the stresses and pressures that could lead to ill-health. Interventions in a specific workplace should aim to create an open and creative work climate, with mutual responsibility for work, co-workers and working conditions. Interventions at the organisational level should include measures that develop leadership focused on health promotion, with clear objectives and common values.
Despite the well-established link between psychosocial factors and MSDs, most interventions have tended to target the individual. Historically, much has been done using ergonomic measures at an individual level to reduce MSDs. However, the results are not as positive as one might expect. This could be explained by fact that interventions that target psychosocial issues in the workplace or an entire organisation have been neglected in the past.
Studies about organisational interventions as a means to improve working conditions and thus reduce MSDs are not as common as studies about individual interventions, but there are some interesting examples. Research has shown that overtime and high demands at work are the most important factors in explaining lower productivity among computer users when lifestyle factors such as low physical activity are discounted. Furthermore, success in reducing MSDs has been shown to require intervention beyond the ‘individual’ level, that is intervention that targets reducing high demands and stressful work assignments. Interventions should envelop both individual and organisational measures in order to be successful, and these should be tailored to each situation.
Psychosocial factors have also been shown to be crucial for a quick return from sick leave. A number of the studies examined in the Swedish research concluded that a supportive working environment, employee participation, and cooperation between management and the employee all increase the potential for successful rehabilitation.
The link between psychosocial factors and MSDs is well-established and is confirmed by this overview of the many studies in this area. However, the research could have focused more on the interesting aspect of organisational interventions. Intervention at an organisational level to improve working conditions and reduce stress could have a major impact on sick leave, productivity and the general health of employees, and would thus be worthy of further study.
Lindegård Andersson, A., Sambandet mellan psykosociala faktorer, upplevd stress och muskulära smärttillstånd, ISM Report 6, Gothenburg, Institute for Stress Medicine, 2009.
Claes Bäckman and Mats Kullander, Oxford Research