Assessing the effects of tool-loading formation on construction workers' postural stability

Falls are a leading cause of fatal and nonfatal injuries in construction. One of the most important steps toward preventing falls is to identify and measure the factors that can affect the construction workers' fall risk. While several intrinsic and extrinsic factors can affect workers' fall risk - such as the effects of aging workers, job site environments, walking habits, workers' experience, and workers' equipment - one unexpected factor that can increase fall risk is the incorrect use of personal protective equipment - including safety harnesses - since when these safety tools are misapplied, they cause instability in the workers' body. The objective of this study was to assess the effects of the formation of tools connected to construction workers' full body harnesses on the fall risk of construction workers. Using the time-series quantitative kinematic measures obtained from inertial measurement units (IMUs) connected to the workers' waistline, the postural stability of a group of subjects was measured by calculating the velocity of Center of Pressure (COPv) and the resultant Accelerometer (rAcc) - lower rAcc and COPv values mean lower fall risk for construction workers. The postural stability for each worker was calculated for two different postures (standing and squatting) and three different formations of the tools attached to the full-body harness. The t-tests' results in the mean values of the calculated rAcc and COPv showed significant differences in the postural stability of subjects with different formations of tools connected to the full body harness. When tools were not connected, workers had the lowest rAcc and COPv values; asymmetric loading formations' rAcc and COPv had higher values than symmetric loading formations. The higher risk caused by asymmetric connected-tools formation express the importance of tools attaching formation to construction workers' safety.