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An electromyographic study of dental work
E Milerad1, M O Ericson, R Nisell
1Department of Occupational Medicine, Karolinska Hospital, Stockholm, Sweden.
Ergonomics
|July 1, 1991
Summary
Dentists experience high muscular load in neck and shoulder muscles, particularly the trapezius, due to sustained static postures during dental work. This study measured muscle activity using electromyography (EMG) to identify ergonomic risks.
Area of Science:
- Occupational Health
- Ergonomics
- Biomedical Engineering
Background:
- Musculoskeletal disorders are prevalent among dentists, often linked to prolonged static neck-shoulder postures and demanding precision tasks.
- The biomechanical factors contributing to these disorders require detailed investigation to inform preventative strategies.
Purpose of the Study:
- To quantify the muscular load levels in neck, shoulder, and arm muscles during routine dental procedures.
- To identify specific muscles subjected to high and low mechanical stress in dentists.
Main Methods:
- Electromyography (EMG) was employed to record muscle activity in various neck, shoulder, and arm muscles.
- Normalized mean, median, 10th, and 90th percentile EMG amplitude levels (% maximal reference contraction, %max-RVC) were calculated during dental work.
Main Results:
- The trapezius muscles exhibited the highest mean EMG amplitudes on both sides (right: 9.0%, left: 7.6% of max-RVC).
- The dominant extensor carpi radialis showed significantly higher load than the non-dominant side, likely due to wrist stabilization demands.
- Low activity was observed in the infraspinatus muscle, indicating minimal arm elevation and external rotation during procedures.
Conclusions:
- Dental work imposes significant muscular load on the trapezius and dominant extensor carpi radialis muscles.
- The findings highlight potential ergonomic risks and inform the development of targeted interventions for dentists to mitigate musculoskeletal strain.