Traditionally, most workplace ergonomic assessments have focused on joint loading in static postures. However, epidemiological studies have shown that three-dimensional dynamic motion is associated with an increased risk of occupational injury and illness. The Biodynamics Lab has developed a unique research program that focuses on the study of occupational joint loading under realistic dynamic motion conditions. The program's goal is to obtain a better understanding of how much exposure to realistic risk factors is too much.
Research in the Biodynamics Laboratory is divided into four areas of study: industrial surveillance; laboratory studies; biomechanical modeling; and injury quantification. Surveillance studies identify links between occupationally-related disorders, the work environment, and body motions observed on the job. Statistical trends developed from these studies can be used to assist in the modification of the work environment. Surveillance studies provide the initial conditions for controlled laboratory investigations. These laboratory studies provide an understanding of how the body responds to real-world working conditions. Once these responses are known, biomechanical models of occupational conditions can be created to provide important information on how the joint of interest is loaded during an exertion. Injury quantification efforts identify the type and extent of an injury or illness so return-to-work status is quantified.
Lumbar Motion Monitoring
The Lumbar Motion Monitor, or LMM, is a lightweight exoskeleton of the spine that is worn during the performance of industrial tasks. The patented LMM was developed in the Biodynamics Lab to provide an accurate method of tracking dynamic back motion in three-dimensional space. The LMM, along with information on the work environment, can be used to accurately predict the level of back injury risk for a given task. The predictive power of the LMM is over three times greater than the original NIOSH lifting guide, which ignores the effects of asymmetry and dynamic motion.
Laboratory investigations using dynamometry attempt to determine the body ’s internal reaction to external loading. Controlled dynamic loads are imposed on the joint of interest in three-dimensional space. The body’s reactions to this loading are studied using a variety of methods. Electromyographic data on muscle activity, lumbar motion, intra-abdominal pressure, and other measures are used to determine the muscle forces on the structure being studied. An extensive study of internal trunk forces was performed using the Asymmetric Reference Frame (ARF) developed in the Biodynamics Laboratory. Data gathered during this study was used in the Biodynamic Lifting Model. The methods used in the study of the internal trunk forces are applicable to any joint of interest. The Biodynamics Laboratory is well equipped with dynamometry equipment and is capable of studying any joint of interest.
Wrist and Finger Motion Monitoring
The Biodynamics Laboratory has established benchmarks for safe and injurious levels of occupational risk motion using wrist motion monitors developed in-house. These monitors, like the LMM, track dynamic motion in three-dimensional space without interfering with a worker’s activities. Studies have determined that dynamic wrist motion plays an important role in cumulative trauma disorder (CTD) risk. The wrist motion monitors have direct application to the study of any hand-intensive work, ranging from industrial assembly to keyboarding.
Ergonomic Analyses of Keyboarding
Using devices and techniques developed in a comprehensive study of grocery store checkout scanning operations, the Biodynamics Lab has the capability to perform detailed assessments of occupational keyboarding and keyboard design. Extensive studies of occupational keyboarding involving wrist motions, finger and spine forces, as well as neck, shoulder and elbow postures are possible using methods proven in previous studies.
Dynamic modeling uses data gathered in laboratory and workplace studies to predict the forces on a joint under different loading conditions. This information can be used to make justifiable workplace design recommendations. The Biodynamic Lifting model was developed using data from studies using the LMM and the ARF. It overcomes the limitations of many early static and dynamic lifting models by considering both motion and asymmetry in its calculations of lumbar spine loading. The Biodynamic Lifting Model is also the only validated dynamic biomechanical lifting model. Biodynamic computer models can be created for any joint of interest using a system similar to that used with the Lifting Model. The current model was recently embedded into the MSC.ADAMS software environment (MSC.Software, Inc.) and uses the LifeMOD biomechanics modeler (LifeModeler, Inc.).
The following is a partial list of sponsors who have funded research in the Biodynamics Laboratory: