Ergonomic Evaluation and Musculoskeletal Disorders: A Guide for Workplace Safety
Ergonomic Evaluation and Musculoskeletal Disorders: A Guide for Workplace Safety
This document provides a comprehensive overview of ergonomic evaluation and its importance in preventing musculoskeletal disorders (MSDs) in the workplace. It covers key aspects of ergonomic risk assessment, including identifying workers at risk, evaluating physical workloads, and implementing preventive measures.
Identifying Workers at Risk
Workers who use display screen equipment for more than 4 hours per day or 20 hours per week are considered at risk for MSDs. Those who use the equipment for 2 to 4 hours (or 10 to 20 hours per week) may also be at risk under certain conditions.
Ergonomic Evaluation
Ergonomic evaluation is a crucial aspect of workplace safety. All companies, regardless of their activity, should conduct ergonomic evaluations as a preventive measure. The first step is to identify and analyze potential ergonomic hazards. Only after identifying these hazards should an evaluation be conducted.
Surveillance Protocols
Surveillance protocols are a series of measures designed to guide health personnel in monitoring workers exposed to ergonomic risks. These protocols help ensure early detection and intervention to prevent MSDs.
Physical Workloads: Concept and Division
Physical workload refers to the psycho-physical demands placed on a worker during the workday. Muscle work can be classified as static or dynamic:
- Static muscle work involves continuous muscle contraction for a sustained period.
- Dynamic muscle work involves a regular succession of short-duration muscle contractions and relaxations.
Methods for Determining Physical Workload
Advantages of Table-Based Methods
Table-based methods for estimating metabolic rate rely on standardized values for different activities, efforts, and movements. These methods are relatively easy to implement and widely used.
Disadvantages of Table-Based Methods
Table-based methods can deviate from reality, leading to less precise estimations compared to methods based on physiological measurements.
Preventing Musculoskeletal Injuries
Several workplace conditions contribute to MSDs:
- Repetitive tasks, especially those with cycles less than 30 seconds or those involving the same movements for more than 50% of the work cycle.
- Jobs requiring prolonged or repetitive efforts exceeding 30% of the worker’s maximal muscle capacity.
- Extreme postures of body segments.
- Extended maintenance of any position.
- Work with vibrating tools.
- Exposure of body parts to cold or contact with hard surfaces.
Gender Differences in MSDs
Studies have shown that women are more likely to experience MSDs than men. This is attributed to several factors, including:
- Preconceived notions that women perform lighter work, leading to underestimation of risks.
- Traditional gender-neutral preventive models based on male work standards.
- Lack of women’s representation in decision-making bodies, including those related to health.
These factors contribute to the perception that men perform harder and more dangerous work, while women perform lighter and safer work. This misconception can lead to a lack of attention to women’s health and safety in the workplace.
Body Map Method
The body map method is a technique used to assess the ergonomic design of workplaces, machines, tools, and other elements. It relies on the discomfort experienced by individuals using these elements. This method is particularly useful for jobs involving awkward postures.
The procedure involves asking individuals to:
- Draw on a body map where they feel discomfort or pain at intervals throughout the workday.
- Rate the intensity of discomfort on a scale of 5 or 7 points.
Alternatively, a simpler procedure can be used where individuals are asked to identify the most uncomfortable areas at intervals throughout the workday.
By implementing ergonomic evaluations and preventive measures, workplaces can significantly reduce the risk of MSDs and create a safer and healthier environment for all workers.