Chronic (work related) upper limb pain syndrome

Work-related upper limb disorders (WRULDs) comprise a heterogeneous group of conditions -165 in all according to a report by the US National Institute for Occupational Safety and Health (NIOSH) (1):

• upper limb disorders are a heterogeneous group of conditions - some specific, some non-specific and some controversial
  • examples of WRULDs include:
    • shoulder disorders e.g. rotator cuff tendinitis
    • elbow disorders e.g. lateral epicondylitis
      • point prevalence of elbow pain has been reported at 11-13% in aeroengineering workers and textile workers,but clinically verified epicondylitis is less prevalent and among the textile workers only 2% had tender as well as painful elbows (1)
    • hand-wrist tendinitis
      • occupations described as at higher risk include board manufacturers, sewers and packers, and assembly line workers
    • carpal tunnel syndrome
      • strongest associations in case-control studies have been with the use of vibratory tools and with activities that frequently flex or extend the wrist
        • link with vibratory exposure has also been described in occupational surveys, notably among foresters
    • chronic upper limb syndrome
      • includes non-specific upper limb pain and so-called 'repetitive strain injury' or 'cumulative trauma disorder' (CTD)
        • terms like this are unhelpful and contentious in the sense that they are ambiguous in their coverage
          • also assume a cause as well as a diagnosis (whereas some of the conditions casually lumped under these headings may also have well-recognised non-occupational causes)
        • some use 'RSI' to refer to chronic upper arm pain for which no diagnosis can be made and which has been ascribed to occupational over-use
          • features of suspected RSI (1)
            • tends to show common features of gradual-onset diffuse pain, paraesthesiae, subjective swelling, and complaints of anxiety, irritation, mood change, fatigue and sleep disturbance
            • clinical signs seem generally to be absent
    • Dupuytren's contracture
      • in general the condition appears to be idiopathic or familial, although some research evidence links the disorder with smoking, alcohol consumption, diabetes and epilepsy
      • is a degree of evidence that Dupuytren's contracture may arise from occupational activities, this being strongest for exposure to hand-transmitted vibration
        
        
• many of these disorders are suspected of being caused by physical work activities (e.g. repetitive jobs and those involving heavy physical work and awkward postures)
  
  
• evidence on work association comes mainly from cross-sectional surveys, with rather few investigations of strong research design (cohort and intervention studies)
  • within limits these suggest that posture may exacerbate neck-shoulder problems and that a combination of repetition, force and posture may cause or aggravate elbow and wrist disorders

Notes:

• a parliamentary report stated with respect to the term repetitive strain injury (1):
  • term 'repetitive strain injury' (RSI), although widely used, is an unhelpful one for the purposes of prescription for two main reasons
    • firstly, the meaning and coverage of the terms (which disorders are included and which are not) is unclear
    • secondly, the name presupposes the cause - that is, repetition
    • the first ambiguity does much to hamper free communication and agreement between specialists and precise reporting and interpretation of research findings. The second is problematic because some conditions that may be caused by repetition can also be caused by non-occupational factors, or even occupational factors other than repetition, such as posture or force
  • a clearer but less often adopted approach is to separate diagnosis from cause

Reference:

• (1) ARC (October 2006). Work-Related Disorders of the Upper Limb.
• (2) Work-related upper limb disorders Report by the Industrial Injuries Advisory Council in accordance with Section 171 of the Social Security Administration Act 1992 reviewing the prescription of the work-related upper limb disorders.Presented to Parliament by the Secretary of State for Work and Pensions By Command of Her Majesty July 2006.