Biological pathways between occupational stress and work-related musculoskeletal disorders of the neck and upper extremity

Stress in the workplace is often linked with cardiovascular disease, hypertension, depression, and low job satisfaction. There is also evidence of an association between occupational stress and musculoskeletal disorders. However, evidence of a direct causal relationship remains elusive. This paper reviews the evidence for a plausible biological pathway between psychosocial stressors in the workplace and musculoskeletal disorders, particularly of the neck and upper extremity; it discusses how job stress can affect blood pressure, hormone levels and the immune system. However, by far the strongest evidence has been obtained through recording muscle electrical activity during low load and stressful tasks such as computer work. The evidence suggests an increase in muscle tension due to the need for postural stabilisation and high visual demands while using a computer keyboard or mouse. This increase occurs during task performance and during rest periods. A potential pathway between these various factors is outlined