Flexible sensor-based biomechanical evaluation of low-back exoskeleton use in lifting.

ABSTRACT

This study aimed to establish an ambulatory field-friendly system based on miniaturised wireless flexible sensors for studying the biomechanics of human-exoskeleton interactions. Twelve healthy adults performed symmetric lifting with and without a passive low-back exoskeleton, while their movements were tracked using both a flexible sensor system and a conventional motion capture (MoCap) system synchronously. Novel algorithms were developed to convert the raw acceleration, gyroscope, and biopotential signals from the flexible sensors into kinematic and dynamic measures. Results showed that these measures were highly correlated with those obtained from the MoCap system and discerned the effects of the exoskeleton, including increased peak lumbar flexion, decreased peak hip flexion, and decreased lumbar flexion moment and back muscle activities. The study demonstrated the promise of an integrated flexible sensor-based system for biomechanics and ergonomics field studies as well as the efficacy of exoskeleton in relieving the low-back stress associated with manual lifting.

This study established and tested a flexible sensor-based ambulatory system for biomechanical evaluation of human-exoskeleton interactions and as a promising new tool for field ergonomics studies in practical or naturalistic settings.Abbreviations MoCap motion capture; WMSD Work-related musculoskeletal disorders; EMG electromyography; IMU inertial measurement unit; TES thoracic erector spinae; LES lumbar erector spinae; WITH tasks performed with wearing the exoskeleton; WITHOUT tasks performed without wearing the exoskeleton; RMS root mean square; RMSE root-mean-square error; r Pearson's correlation coefficient; ASIS anterior superior iliac spine.