Biomechanics and Human Factors

MERC’s Reliability and Human Engineering Division employs biomedical and industrial engineers who specialize in the analysis, adaptation, and redesign of work and work environments in order to optimize human performance.  Work activities include human factors analysis; analysis of crew stations; design of tools and workspace; ergonomic risk analysis, mitigation, and training; and rehabilitation engineering.  We quantify the physical and cognitive requirements of tasks, develop criteria for matching people and tools with task requirements, study the ergonomic risk involved in jobs and how to mitigate it, develop design criteria for tools and work environments to support human activity, and many other human factors-related activities.



Laboratories and Equipment

MERC has specially-equipped laboratories which support the projects and initiatives undertaken by the biomechanics and human factors team.  Capabilities such as 3-dimensional motion analysis, computer-based biomechanical simulation, and wireless biometric sensing allow us to predict the physiological response of the human body to external loads and environmental conditions that are experienced in the home, in the workplace, or on the battlefield.

A well-equipped biomechanics lab, located on the campus of Mercer University, provides our engineers with the facilities to perform a range of complex biomechanical testing and analysis not available anywhere else in this part of the country. The lab is equipped with an extensive array of biomechanical sensing systems and simulation software including:  3-dimensional motion capture, floor load, wireless sensors, and video.

The motion capture system, manufactured by Northern Digital Inc., includes three sensor bars that together provide 0.4 mm resolution of motion measurement within a 300 cubic meter sensing area.  Three forceplates, also manufactured by Northern Digital, allow 16-bit measurement of human ground reaction forces up to 8,000 newtons.  The wireless sensors include six individual channels of electromyography, and two channels for wireless force and/or grip sensors.

Simulation software, including Open Sim, AnyBody, and Visual3D allow the biomedical engineers to estimate physiological responses at the joint and tissue level.




The experience and expertise that MERC has in the disciplines of biomechanics and human factors is evidenced by the multitude of projects which have been accomplished by the MERC team. These projects cover the full range of applied research and development, ergonomics, crew station work analyses, and rehabilitation engineering support.  A few examples follow.

In an F-15 Fuel Cell Ergonomic Intervention project, MERC analyzed the maintenance processes and identified the ergonomic risks involved in the fuel cell build-up tasks required during F-15 depot level maintenance.

Building up fuel cells on the F-15 aircraft requires manually installing heavy rubber bladders, fitted with brass plumbing flanges, into six areas of the fuselage.  After the plumbing is installed, the mechanics forcefully stuff pre-cut blocks of stiff, reticulated foam into each fuel tank to fill up all of the available space.

Ergonomic risks included: high finger loading, awkward postures leading to high exertion at extreme joint angles, high compressive loads for wrist, elbow, shoulders, and knees, high grip forces, and extreme heat and humidity.

MERC developed and implemented solutions and associated tools to improve the efficiency of the fuel cell buildup process and mitigate the risks to which the mechanics were exposed while accomplishing the work.

Overall ergonomic risk was reduced by more than 40%, while task time was reduced by seven man-hours per aircraft, resulting in savings of approximately $100k per year, with return on investment (ROI) of six months.

In another example of successful projects, the Physician Directed Functional Job Analysis program is an ongoing, competitively-awarded contract with Robins Air Force Base. Many workers at RAFB have job-related-injury physical restrictions which prevent them from participating in productive work without special accommodations.

The goal of this program is to provide these workers with ergonomic and medical evaluations and recommendations to return them to productive work.  The program is a part of a return to work process at Robins in which MERC fills the role of the Physician Directed Evaluation Team (PDET).

MERC’s staff of ergonomists and rehabilitation engineers works with an orthopedic surgeon to evaluate personnel to determine the appropriate characteristics of a safe and productive job and analyze jobs to determine the best fit.

This program has resulted in a consistent 80:1 ROI.

As an example of crew station work analysis, MERC executed a project to redesign the MH-53 helicopter Flight Engineer seat and integral restraint system to improve ergonomic access, crash protection, and situational awareness over extended day and night time missions.

MERC performed task, workload, and ergonomic analyses needed to set parameters for the seat design and modeled the flight engineer using simulation software.  The software automatically collected human factors data from the simulation.  The software also enabled three-dimensional visualization, which enhanced the designers’ ability to identify issues and work through design iterations more efficiently.

A full task and crash scenario simulation allowed the designers to evaluate the seat design relative to the human factors design requirements.  Biomechanical analysis was used iteratively throughout the seat development process, including design, trade-off analysis, and design validation.

During the design process, reach and control envelopes were developed for 5 percentile and 95 percentile males with which to determine the access and adjustability parameters necessary for functionality.

The seat was successfully designed, built, and integrated into the Special Operations Forces fleet of MH-53 helicopters, resulting in improved mission capability and reduced risk of injury to personnel.



In addition, MERC has worked supporting Georgia Vocational Rehabilitation involving extensive assessment of physical and cognitive workload requirements for a wide range of jobs, and the development of technological interventions to support the successful placement of individuals with many different types of disabilities into those jobs.

We also support school systems across Middle Georgia to help them more effectively educate children who have a variety of physical and cognitive disabilities. We use our expertise in human development, learning modalities, cognitive processes, and adaptive technology to guide teachers and schools in effective techniques and technologies for teaching and learning.

For more information email us at

Related Biomechanics and Human Factors Projects

MH-53 Flight Engineer Seat Modification

MERC designed modifications to the Special Operations Forces Flight Engineer's Seat in the MH-53 helicopter

Vocational Rehabilitation

MERC ergonomists played a key role in helping VR rehabilitate hundreds of individuals over ten years of contracting with the agency.

Human Factors Process Improvement

The Physician Directed Functional Job Analysis program is an ongoing, competitively awarded contract with Robins Air Force Base.

F-15 Fuel Cell Ergonomic Intervention

MERC performed a series of tasks in the successful execution of the F-15 Fuel Cell Ergonomic Intervention.