Ergonomics

Millions of workers in the US spend hours sitting at their desks, nonetheless, a very few percentage of the workforce population is provided with an ergonomic chair, lumbar support cushions or a padded mousepad. Extended exposure to compressive forces at the wrist can lead to occlusion of the nerves that actuate the muscles of our hands, ultimately leading to the rising incidence of carpel tunnel syndrome in white collar workers. Add to that a stiff chair with armrests that elevate your shoulders by an amount that might seem to be comfortable. While this might seem like added comfort, this position will actually build up tension in your back muscles and result in potential muscle spasms, prolonged tension at the joints thus putting you at a heightened risk of ligament injuries. On top of this, you are not provided with a lumbar support cushion, hence your natural posture is altered, incurring in efforts to compensate for the posture alteration.  All these factors play a role into injury production within work environments. Accordingly, our team of experts make use of their vast understanding of anatomy, anthropometrics, physiology, biomechanics and ergonomics to first quantify the forces acting on the various tissues of the body and consequently assess injury production potential in specific working environments.

Another aspect of ergonomics which NBI assess is the actual design of the workplace. Shared offices have allowed for smaller companies to have a working space for their employees and incentivize collaborations. But it also increases the number of people within the same space, hence reducing spaces and increasing the risk of collisions with walls, co-workers or even sharp edges. An impact to the head can be severe enough to cause a brain injury but mild enough to not present immediate symptoms nor show a visible injury in an MRI scan. Our experience at NBI dealing with mild traumatic brain injuries has made us understand the importance of both linear and rotational accelerations when impacts, falls and sudden fast lateral movements of the head occur in the assessment process of injuries related to the brain. Nonetheless, measuring these acceleration forces without sensors require a holistic approach to the specific incident; how was your body moving, did you experience a free fall or did you fall due to an external force pushing your body, did you fall on your side, did you use your arms to dampen the fall, so on and so forth. Thus, NBI uses expertise in inertial analyses to understand the potential of brain injuries in diverse situations.

ADDITIONAL INFORMATION ON TOOLS AND SOFTWARE THAT NBI HUMAN FACTORS EXPERTS USE IN THEIR FORENSIC WORK:

  • Luminance meters are detectors that measure photometric brightness (i.e., they measure the amount of light reflected to the eye from the object and its background). “Luminance” refers to the amount of light that is available for vision. Human factors experts, for example, may use these detectors to measure object contrast, which refers to the relationship between the luminance of an object and the luminance of the object’s background.
  • Through a process of ranging, the rangefinder device is used to assess distance from the observer to a target. Estimating distance is an essential part of nearly every human activity such as walking or driving. The key to safe driving is anticipation, and, for example, a driver could hardly perform effectively without a reasonably accurate knowledge of her distance from the vehicle in front to calculate a safe following distance on the road.
  • I.DRR software allows for inclusion of human factors in the process of accident/crash reconstruction. This software allows human factors experts to evaluate various factors such as age, gender, disability, fatigue, temporary distraction, general visibility, glare and dark adaptation that impact cognition, perception, reaction time and behavior in the context of driving performance.

Moreover, the design of the office should be preformed from an ergonomic  perspective. To analyze potential injuries, we would need to consider aspects such as the space between desks, the height of the desk, the height of monitors on top of the desk, the width of the hallways, the gyration angle of a door, objects in the floor that might cause trips or falls, the material of furniture , as well as their design (sharp edges or smooth edges). Overall, injury production analyses need to reproduce plausible scenarios, take all these different variables into consideration along with the anthropometrics of the employees. It is not the same to take into account 50th percentile anthropometric values than 95th percentile anthropometric values of a population. NBI’s analyses consider a holistic approach to these problems.

Leading Expert

RAMI HASHISH, PHD, DPT