Experimental Analysis of Handcart Pushing and Pulling Safety in an Industrial Environment by Using IoT Force and EMG Sensors: Relationship with Operators’ Psychological Status and Pain Syndromes

Abstract

Non-ergonomic execution of repetitive physical tasks represents a major cause of work-related musculoskeletal disorders (WMSD). This study was focused on the pushing and pulling (P&P) of an industrial handcart (which is a generic physical task present across many industries), with the aim to investigate the dependence of P&P execution on the operators’ psychological status and the presence of pain syndromes of the upper limbs and spine. The developed acquisition system integrated two three-axis force sensors (placed on the left and right arm) and six electromyography (EMG) electrodes (placed on the chest, back, and hand flexor muscles). The conducted experiment involved two groups of participants (with and without increased psychological scores and pain syndromes). Ten force parameters (for both left and right side), one EMG parameter (for three different muscles, both left and right side), and two time-domain parameters were extracted from the acquired signals. Data analysis showed intergroup differences in the examined parameters, especially in force integral values and EMG mean absolute values. To the best of our knowledge, this is the first study that evaluated the composite effects of pain syndromes, spine mobility, and psychological status of the participants on the execution of P&P tasks—concluding that they have a significant impact on the P&P task execution and potentially on the risk of WMSD. The future work will be directed towards the development of a personalized risk assessment system by considering more muscle groups, supplementary data derived from operators’ poses (extracted with computer vision algorithms), and cognitive parameters (extracted with EEG sensors).

Workload and stress evaluation in advanced manufacturing systems

“…The experimental tasks usually include motor and cognitive activities. As in Table 2, motor tasks consist of manual assembly activities [9,15,32] that, in some studies, are executed by using collaborative robots [21,23] or augmented reality glasses [10], or working in different operational (e.g., push vs. pull) contexts [12,19]. In other cases, the task type involves other activities, such as crimping [8] or replacement of spare parts [6].…”

“…In laboratory experiments, augmented and virtual reality are adopted to simulate manufacturing contexts while executing tasks, and sensitive and fragile measurement equipment [15], difficult to integrate in real manufacturing environments, is used. In a real context [11,12,21], such as an automotive assembling line [32], wearable technologies for measurements aim to not interfere with the tasks.…”

“…On the other hand, contributions tend to explore only physical factors such as workload, fatigue and ergonomics and neglect the stress phenomenon. Some current contributions focus on human factors, such as cognitive load in manufacturing [7][8][9] and especially in assembly tasks [10,11] or push/pull tasks [12,13], though without assessing the phenomenon of stress.…”

Development of a Neuroergonomic Assessment for the Evaluation of Mental Workload in an Industrial Human–Robot Interaction Assembly Task: A Comparative Case Study

“…In HRI, physical and cognitive ergonomics play a major role in an effective and efficient HRI [13]. Physical ergonomics deals with human physical activity, regarding its limitations and capabilities [19]. Cognitive ergonomics deals with the mental processes of humans influenced by other systems involved in the environment [20].…”