Author Archives: Ranjana Mehta

About Ranjana Mehta

Assistant Professor

An employee uses a keyboard and mouse.

Office and Tech Ergonomics

This research line focuses on office ergonomic risk assessment and mitigation. We aim to develop a survey where people can report the physical impact a type of software, physical office environment, or the technology (device) has on its user and what aspects of the design can be altered to decrease that risk. This research is funded by the Office Ergonomics Research Committee, ExxonMobil, and HP.

Two students assist an elderly patient in a lab.

Obesity, Stress, and Neuromuscular Functioning in the Elderly

Obesity, a pervasive condition in the geriatric population, has serious implications on the structures and functions of both the aging brain and the musculoskeletal systems that have been linked to cognitive and neuromuscular decline, respectively. However, it is not currently known if motor impairments in obese older adults are linked to obesity-related neural dysfunction. Building on our first line of research (role of brain in fatigue development), we explore functional brain activation across different motor-function related cortical regions in response to fatigue to investigate the impact of obesity on the aging brain. We examine fatigability of important lower extremity muscles that are critical to activities of daily living such as balance/locomotion. Understanding compensatory activation of different brain regions, or the lack thereof, along with musculoskeletal outcomes during the use of these muscles will provide critical information on the neuromuscular limits of the obese geriatric population. This can provide the evidence base to inform development of specific falls prevention interventions that target obesity-related improvements in brain and motor function in older adults. This research is funded by the NIA.

A group of young students work in a classroom using standing desks.

Cognitive Benefits of Standing Desks

This research emphasizes the significance of built environment considerations in classrooms and work offices, such as the stand/sit workstations, that allow schools and companies to effectively address health outcomes with sedentary behavior and cognitive benefits (productivity) simultaneously.

Workers on an offshore oil rig

Integrating Physical and Cognitive Ergonomics

Physical ergonomics is concerned with human anatomical, anthropometric, physiological and biomechanical characteristics as they relate to physical activity. Cognitive ergonomics is concerned with mental processes, such as perception, memory, reasoning, and motor response, as they affect interactions among humans and other elements of a system. Most occupational tasks involve some level of mental/cognitive processing in addition to physical work, so that ideally they should be considered together when examining behavior at work. High cognitive demands can influence physical work; and physical activity can influence cognitive processing.

Fatigue is a complex, multifaceted phenomenon and is most commonly defined as the inability to maintain desired performance. The contributors to fatigue may be either physical or psychological and the occurrence site may be the brain or the body, but investigators have typically focused on only one source/site alone. Traditional fatigue evaluations are limited to biomechanical, muscular, and physiological responses, i.e., are focused on the body. Examining the role of brain functioning during fatigue development is critical to extend our knowledge on the etiology and potential mechanisms of fatigue. Central to the goals of NeuroErgonomics, this line of research is novel in investigating mechanisms of fatigue development, both at the neural (brain) and the musculoskeletal (body) levels. What is the role of the brain in fatigue development? How does it affect downstream peripheral responses? What are the potential mechanisms through which stress can increase fatigability? To address these important questions, we employ an integrative brain-body approach to explore potentials pathways of fatigue development under different scenarios (such as high stress or intense movements). For example, we have found that stress can limit activation in the prefrontal cortex that in turn can impair musculoskeletal performance and increase fatigability during motor activities.