SPINAL MOMENTS DURING CONTINUOUS SEQUENTIAL LIFTING, CARRYING, AND LOWERING

摘要

Manual Material Handling (MMH) tasks, such as lifting, lowering, and load carrying, are common in various industries. Many studies have measured the spinal moments during lifting, lowering, and carrying tasks (e.g., Hoozemans et al. 2008; Marras et al., 2002; Rose et al., 2013). However, these studies focused on performing a single MMH task, while in many cases at a real work environment the workers conduct this task in continuous sequences (e.g., lifting a box from a pallet, carrying it, and lowering it onto a shelf). The need for tools for analyzing continuous-sequence MMH was also emphasized by Dempsey (1999), Garg and Kapellusch (2009), and Harari et al. (2017). Further, Straker et al. (1997) used a 2D inverse dynamic model, and found that peak spinal loading during a continuous-sequence MMH process was different than the loading during the single MMH tasks that comprised it. They concluded that using methods developed for single MMH to estimate risk during continuoussequence MMH is unacceptable.