The aim of this study was to examine the mechanical work performed by different joints in the human body and to correlate it with metabolic energy expenditure. The motivation for this was to better understand human performance at sea. Long-duration ship activities aggravate the chances of various motion disorders including motioninduced fatigue, motion sickness, sopite syndrome, and nausea. These disorders are major biodynamic barriers that reduce the efficiency of crew members and ship operators during operational tasks. The methodology of this research included developing a mathematical model of the human body to calculate the mechanical work expended while maintaining balance. This will aid in understanding the performance of humans during shipboard tasks and also help in formulating strategies to improve the efficiency of human performance. Experimental data from human subjects were collected on a ship motion simulator for twelve different deck motion conditions representing a typical frigate operating in four sea states with three ship headings relative to the principal wave direction. Data were collected using a motion capture system, foot pressure sensors, a load cell, and a metabolic analyzer. The mechanical work performed by the human body and individual body joints was calculated by developing a ninety-six degree of freedom mathematical model. This paper presents the results on variation of metabolic levels with sea severity, variation of metabolism demands with gender, correlation between mechanical work and metabolism, direct comparison of mechanical work with metabolic energy, and distribution of mechanical work among 14 body joints as a function of deck motion. The results of this research provide significant information towards understanding the impact of ship motion on human performance which can contribute to improvements in operational planning and ultimately safety of shipboard personnel.

Additional Metadata
Keywords Metabolism, Motion-induced fatigue, Shipboard postural stability
Conference The International Conference of Control, Dynamic Systems, and Robotics, CDSR 2014
Citation
Kaur, G. (Gurwinder), Langlois, R.G, & Afagh, F. (2014). Mechanical energy expenditure while maintaining postural stability in shipboard motion environments Pt II: Results. In International Conference of Control, Dynamic Systems, and Robotics.