To date, one-third of work-related injuries are caused by overexertion and prolonged awkward postures in manual material handling, such as in manufacturing and construction work. Work-related overexertion alone costs the US economy $13.7 billion in direct costs, posing a substantial societal problem. Developing appropriate intervention strategies to reduce the risk of work-related injuries relies on the accurate and comprehensive assessment of physical exposure. Traditionally, information about work tasks, force exertion, and posture have been obtained using such methods as direct observation and force measurement with tethered devices, which are time- and labor-intensive and intrusive to workers. To overcome these limitations, my Ph.D. dissertation focused on developing an exposure assessment method that can be used remotely and wirelessly in field settings. The method I developed relies on wearable inertial sensing to estimate physical exposures of workers to different work conditions by classifying types of work task (e.g., carrying, lifting), task intensities (e.g., the weight of the load to be carried or lifted), and task durations. My work makes fundamental biomechanical contributions to our understanding of the human body’s response to external loads in dynamic tasks, as well as providing a framework for applying this knowledge to predictive modeling techniques.
Related Publications and Presentations
- Lim, S., & D’Souza, C. (2019). Statistical Prediction of Load Carriage Mode and Magnitude from Inertial Sensor Derived Gait Kinematics, Applied Ergonomics, 76, 1-11. Link
- Lim, S. (2019). Combining wearable sensing and predictive modeling for biomechanical exposure assessment in specific material handling tasks. Doctoral dissertation. University of Michigan, Ann Arbor
- Lim, S., & D’Souza, C. (2019, accepted). Gender and Parity in Statistical Prediction of Anterior Carry Hand-Loads from Inertial Sensor Data. Proceedings of the 63nd Annual Meeting of the Human Factors and Ergonomics Society (HFES)
- Lim, S., & D’Souza, C. (2019, under review). Measuring Effects of Two-handed Side and Anterior Load Carriage on Gait Kinematics using Wearable Inertial Sensors.
- Lim, S., & D’Souza, C. (2019, in progress). A Systematic Review of Inertial Sensing-Based Ergonomic Exposure Assessment.
- Lim, S., & D’Souza, C. (2018). Inertial Sensor-based Measurement of Thoracic-Pelvic Coordination Measures Predicts Hand-Load Levels in Two-handed Anterior Carry. Proceedings of the 62nd Annual Meeting of the Human Factors and Ergonomics Society (HFES), Philadelphia, PA, October 2018. Link
- Lim, S., & D’Souza, C. (2018). Predicting Hand-load Carrying Strategy and Load Level from Gait Kinematics Obtained from Wearable Inertial Sensor. Poster presented at the Michigan Institute for Computational Discovery and Engineering (MICDE) 2018 Annual Symposium, Ann Arbor, MI, March 2018. Link
- Lim, S., & D’Souza, C. (2017). Statistical Prediction of Hand Force Exertion Levels in a Simulated Push Task using Posture Kinematics. Proceedings of the 61st Annual Meeting of the Human Factors and Ergonomics Society (HFES), Austin, TX, October 2017. Link
- Lim, S., & D’Souza, C. (2017). Statistical Prediction of Hand-load Carrying Strategy and Load Level from Wearable Inertial Sensor Data. Poster presented at the 2017 Engineering Graduate Symposium, Ann Arbor, MI, November 2017. Link - Won “1st Place at the Industrial, Operations, and Financial Engineering session” Link
- Lim, S., & D’Souza, C. (2017). Statistical Prediction of Hand-load Carrying Strategy and Load Level from Wearable Inertial Sensor Data. Poster presented at the 60th IOE Anniversary Poster Reception, Ann Arbor, MI, November 2017.
- Lim, S., Bixler, K., Chiang, J., & D’Souza, C. (2017). Preliminary Investigation of Ex- ternal Load Prediction in Manual Material Handling. Poster presented at the Education and Research Center (ERC) Regional Research Symposium, Ann Arbor, Michigan, March 2017. Link - Won “Center for Occupational Health & Safety Engineering (COHSE) Director’s Award” Link
- Lim, S., Case, A., & D’Souza, C. (2016). Comparative Analysis of Inertial and Optical Motion Capture Derived Kinematics during Isometric Push-Pull Exertions. Proceedings of the 60th Annual Meeting of the Human Factors and Ergonomics Society (HFES), Washington, DC, September 2016, pg: 970 - 974. Link
- Lim, S., Case, A., & D’Souza, C. (2016). Comparing Postural Responses to Push and Pull Task Demands using Optical Motion vs. Inertial Measurement. Proceedings of the 9th In- ternational Scientific Conference on the Prevention of Work-Related Musculoskeletal Disorders (PREMUS), Toronto, Canada, June 2016.
- Lim, S., Bixler, K., Chiang, J., & D’Souza, C. (2016). Preliminary Investigation of External Load Prediction in Simulated Manual Tasks. Poster presented at the Center for Ergonomics open house, Ann Arbor, Michigan, December 2016.
- Lim, S., Case, A., & D’Souza, C. (2016). Development of Classification Algorithm for Esti- mating Physical Task Demands Using Inertial Sensors. Poster presented at the Education and Research Center (ERC) Regional Research Symposium, Ann Arbor, Michigan, March 2016. Link
- Case, A., Lim, S., & D’Souza, C. (2016). Accuracy and Precision of Inertial Sensors in Ergonomics Evaluations of Static vs. Dynamic Work Posture. Poster presented at the Education and Research Center (ERC) Regional Research Symposium, Ann Arbor, Michigan, March 2016. Link - Won “People’s Choice Award”
- Lim, S., Case. A., Chung, C., Keci, A., & D’Souza, C. (2015). Methodology for Vali- dating Inertial Sensors in Ergonomics Posture Assessment. Poster presented at the Center for Ergonomics open house, Ann Arbor, Michigan, December 2015.
- Keci, A., Lim, S., & D’Souza, C. (2015). Validating Inertial Sensors for Ergonomics Posture Assessment. Poster presented at the 2015 UROP Summer Symposium, August 2015.
- Chimbala, N., Lim, S., Diaz, G., & D’Souza, C. (2015). Preliminary Validation of IMUs for Ergonomics Posture Assessment. Poster presented at the 2015 UROP Winter Symposium, April 2015