Ergonomic assessments offer valuable insight into the health status of the workforce. Data from various tests help provide Occupational Safety and Health (OSH) professionals with key information that determines the need for corrective action. Whether it be used before employment or before returning to work after injury, what’s known as a Fitness For Duty (FFD) test can be completed to judge a worker’s ability to complete certain tasks. On top of that, annual or regular assessments can track changes in the health of the workforce or catch workplace injuries before they develop. This article will outline 4 key ergonomic assessment tools and evaluate the addition of force gauge measurements to any health examination.

NIOSH Lifting Equation

The National Institute of Occupational Safety and Health (NIOSH) Lifting Equation is a general function that computes the Recommended Weight Limit (RWL), which is an appropriate amount of weight that all healthy employees can lift or lower over the course of an 8-hour work shift without increasing the risk of a musculoskeletal disorder (MSD) to the lower back. The Equation takes into account the location of the object, distance carrier, frequency of action, and any twisting involved. Any design of an experiment would require standardized movement as measurements must be accurate in order to offer an accurate RWL.

Snook Tables

Designed by Liberty Mutual Research Institute for Safety, Snook Tables function similarly to the NIOSH Lifting Equation. Snook Tables are readily used to determine risk of MSDs in regard to pushing, pulling, and carrying objects when the actual weight of the object is greater than the recommended design limit from the Snook Table. Variables necessary to know are weight of the object, force required to move it, distances required to move, and frequency of action. Unique to Snook Tables, when a task requires a mixture of movements and frequencies, those frequencies can be combined to analyze the task as a whole.

Rapid Upper Limb Assessment

Rapid Upper Limb Assessment (RULA) focuses on movements related to the upper body, such as torso, shoulders, and arms. The tool provides a score (1-7) where 1 is low and 7 is high in risk of developing an MSD. During an assessment, evaluators note angles of the body to determine risk. Most often, the larger the angle, the higher the risk. Overall, RULA identifies poor posture and indicates whether corrections need to be made.

Image courtesy of ErgoPlus

Rapid Entire Body Assessment

As an expansion to RULA, Rapid Entire Body Assessment (REBA) uses the same techniques to offer risk assessment on all body parts. Each evaluation looks at the posture of specific body groups in order to assign a risk value as well as whether corrective action should take place. A score of 1 indicates no issues while 15 indicates high risk and immediate need for change. REBA is a tool that has a short process allowing it to be repeated for multiple body parts. Analysis starts by identifying a job that should be tested, understanding specific tasks, and then evaluating those tasks.

Image courtesy of ErgoPlus

Addition of Force Gauges

Force gauges are measuring instruments that quantify force. Most often they are used in research, however, they have work environment applications. Specifically, in the work setting, digital force gauges are used to determine the force or pressure required to complete certain tasks. Digital force gauges can be coupled with electromyography, a diagnostic tool that graphs the electrical signals from muscle contractions.

Ergonomic assessments can predict risk of developing MSDs. However, most of the analysis is completed with measurements and calculations of a single photo that cannot be applied to the entire workforce. Moreover, these assessments don’t account for location of applied force on certain body systems. By introducing force gauge measurements to ergonomics, analysis can be refined creating more accurate results. Bioergonomic assessments get precise data on which muscle groups are utilized, potentially identifying a problem that otherwise would’ve been overlooked using REBA, RULA, NIOSH Lifting Equation, or Snook Tables.


Fitness for Duty (FFD) tests and regular ergonomic assessments allow OSH professionals to gain a deeper understanding of their workforce’s health and well-being. With the addition of force gauge measurements, evaluators gain more accurate and precise data often missed by typical assessments. HFit’s BioErgo suit utilizes electromyography to get big data insights on simple ergonomic assessments. Identify, manage, and minimize the risks of MSDs in the workplace. Join the BioErgo Revolution.

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