Median mononeuropathy among active workers: are there differences between symptomatic and asymptomatic workers?

Area of Science:

• Occupational Health
• Neurophysiology
• Ergonomics

Background:

• Carpal tunnel syndrome (CTS) is a common condition affecting the median nerve.
• Understanding factors differentiating symptomatic from asymptomatic median mononeuropathy is crucial for prevention and management.
• Previous research indicates a multifactorial etiology involving electrophysiologic, ergonomic, and psychosocial elements.

Purpose of the Study:

• To investigate differences between symptomatic and asymptomatic workers with electrodiagnostically confirmed median mononeuropathy.
• To identify demographic, anthropometric, psychosocial, electrophysiologic, and ergonomic predictors of CTS symptoms in active workers.

Main Methods:

• Cross-sectional study involving 700+ active workers across six worksites (manufacturing and clerical).
• Electrodiagnostic testing (nerve conduction studies) identified 184 workers with median mononeuropathy.
• Workers were stratified based on the presence or absence of hand symptoms (pain, numbness, tingling, burning).

Main Results:

• Symptomatic workers were more likely to be female, have jobs with high hand repetition, use more force, and exhibit abnormal wrist postures.
• A trend towards more prolonged median sensory distal latency was observed in symptomatic individuals.
• Having no history of diabetes was associated with a higher likelihood of reporting CTS symptoms.

Conclusions:

• Female gender, higher job ergonomic risks, and absence of diabetes are associated with symptomatic median mononeuropathy.
• Psychosocial factors showed limited discriminatory power in predicting CTS symptoms.
• Current predictive models lack the precision for individual-level risk assessment.