Local Ergonomic Strength Testing Services

Employee Selection Systems

Employee Selection Systems A variety of factors, external and internal, influence a company's decision to implement employee selection and placement programs for physically demanding work tasks. These factors include but are not limited to:


    • Federal and State Regulations

    • Raising Productivity

    • Injury Reduction

    • Marketplace Competitiveness

    • Reducing Workers' Compensation Costs

In developing competitive strategies, many companies understand that recruiting and keeping skilled and talented people are important to their long-term success. Therefore, the development and implementation of a valid selection system are important elements of any recruitment strategy. This is particularly important for companies where the jobs are in manufacturing or involve manual handling and where any risk of musculoskeletal injury is present.

According to the U.S. Bureau of Labor Statistics, job-related injuries in 1997 cost U.S. companies over $45 billion. Strain/ sprain injuries and musculoskeletal disorders account for a significant percentage of the reported workers' compensation costs. Some companies credit the ability to match a worker to an appropriate job, to sharp reductions of on-the-job injuries.

Pre-employment, or post-offer, pre-placement testing has been subject to the erroneous assumption that federal regulations prohibit such tests. While medical tests are illegal if given solely to make pre-employment hiring decisions, conducting valid physical ability tests is legal. A valid physical ability test can determine if an applicant or worker can perform the essential elements of a particular job. Such a test meets the legal standard of being a business necessity, and employers have a legal right to conduct such tests.

Strength Testing

Many jobs require workers to lift objects (e.g. boxes and bags) in many different ways. Loads are lifted to different heights at different rates. Additionally, workers use a variety of postures when lifting. Medical research shows that materials lifting task that are too heavy for the lifter cause about 50% of all industrial low back injuries. The ergonomic approach to reducing back injuries caused by lifting is to match the worker to the job. This is done in two ways:

    • Change the job to fit the industrial population. This involves engineering the risk out of the task.

  • When job redesign is not an option, select workers who have the physical capacity to meet the demands of the job.

While job redesign is an effective ergonomic strategy, it is not always possible. Many products and containers are already designed at their optimal weight and size. When the demands of a materials lifting task cannot be engineered out of the task, the second option is to select workers who are able to meet the demands of the job. Research has demonstrated that isometric strength tests are an effective measure of a prospective worker's ability to perform manual materials handling tasks. Isometric strength is the maximum force that a muscle group can exert without movement. Tests of isometric strength are easy to perform since they require only a single maximal contraction.

Isometric tests are much safer than other kinds of tests such as those that ask workers to lift increasingly heavy weights to establish a worker's maximal level of strength. This is because isometric tests do not ask workers to lift weights, only exert force. If a worker can only exert 25 lbs. of force, that worker's score is 25lbs. On the other hand, if a worker is very physically capable, he or she may exert 125 lbs. or more of force on the same test. In neither case is the worker endangered by the test since the test measures the maximal capacity to lift by forces generated by the worker.

Productivity & Injury Reduction

Research has also demonstrated that strong workers are up to 8-12 times more productive than weak workers in jobs that consist primarily of strength-dependent activities. Not only can strength testing increase productivity, it can reduce injuries. Studies have also shown that as workers required to lift weights that approach their maximal capacity, their back injury rates increase by as much as 300%. Strength testing permits the selection of the most productive workers while avoiding those persons likely to injure themselves and other workers.


MED-TOX offers testing services for employers in the Southern California region. Testing can be conducted in our offices or on site. Services include:

    • Cost-effective Physical Ability Testing Services

    • Job-Related Test Validation Studies

    • Specialized Job Analysis Services

  • Ergonomic Consultation
Contact MED-TOX Health Services for further information.