Prediction model of the effect of postural interactions on muscular activity and perceived exertion

Abstract

Musculoskeletal disorders are a prevalent disease in many Western countries. While a large number of ergonomic analyses and assessment methods are nowadays available, most current methods that assess exposure calculate overall risk scores of individual body segments without considering interaction effects of exposure variables. Therefore, a study was conducted that aimed at investigating and quantifying interaction effects of trunk inclination and arm lifting on ratings of perceived exertion (RPE) and muscle activity. A multiple regression model to predict musculoskeletal load under consideration of interaction effects was derived. The study revealed that there is a significant interaction effect of trunk inclination and arm lifting. Furthermore, final regression models explained variance in exposure variables in a range of R 2 ¼ 0.68 to R 2 ¼ 0.147 with a subset of two to three inputs. The predicative equations support the computerbased post-processing of sensor data.Practitioner summary: This article elaborates on the importance of interaction effects of working postures on assessment results of load. In practise, easy to-use-methods for an assessment of working postures are needed. Therefore, a regression model is derived, which facilitates the quantification of work load under consideration of interaction effects. The use of this regression model for the assessment of posture data gathered by range sensors is recommended.

Impact of Fatigue on Ergonomic Risk Scores and Foot Kinetics: A Field Study Employing Inertial and In-Shoe Plantar Pressure Measurement Devices

“…Occupational fatigue, often caused by high job demands and long duty periods, is associated with the reduced occupational health and safety of the worker, resulting in high social and financial costs [ 1 ], and is, therefore, a major problem for modern industrial societies [ 2 , 3 , 4 ]. Following the International Standardization Organization (ISO) 6385 document (2016) pertaining to the integration of ergonomics into the designs of work systems, work-induced fatigue is characterized as a non-pathological manifestation of excessive strain, either mental, local, or general, that is entirely reversible with rest [ 5 ], and diminished human performance capabilities are attributed to the inability to effectively manage physiological stressors [ 6 ].…”

“…Furthermore, fatigue is also a problem in the context of working in a static position, like sitting for a prolonged period as in office work, and may cause a change in posture [ 11 ]. Studies have shown that unergonomic working positions correlate with increased perceived exertion [ 1 ], physical discomfort [ 12 ], and MSDs [ 13 ] that can negatively affect the work and private life quality of employees [ 14 ]. A wide body of literature describes the general causes and effects of occupational fatigue [ 4 ], while few studies have examined fatigue in the construction industry.…”

“…Wearable devices are widespread solutions aimed at enhancing work efficiency, promoting the well-being of workers, and facilitating interactions between users and their environment at any time and location [ 18 ]. Several studies have examined kinematic or kinetic indicators to derive appropriate ergonomic measures [ 1 , 5 , 8 , 19 ]. Inertial measurement units (IMUs) can be employed to detect kinematic factors throughout a longer-duration work process [ 20 , 21 ].…”

Why cumulative loading calculated using non-weighted integration may not be suitable for assessing physical stress of the lower back: an empirical investigation of strain during lifting and lowering tasks

“…As shown in Figure 2, participants performed a twodimensional, symmetric movement in the sagittal plane with an external weight held in both hands. Since empirical evidence suggests a significant influence of trunk inclination and shoulder angle on the muscle activity of RES/LES (Hellig et al 2020), the movement was standardised accordingly. The trunk inclination was standardised to a range of 0 to 40 with the angle measured between the vertical line and the trunk longitudinal axis as shown in Figure 2.…”

Inertial Motion Capturing in Ergonomic Workplace Analysis: Assessing the Correlation between RULA, Upper-Body Posture Deviations and Musculoskeletal Discomfort

“…Work demands play a vital role in the development of musculoskeletal pain, often mainly due to low physical capacity and imbalances [8]. In industry, there is evidence that unergonomic working positions correlate with increased perceived exertion [9] and physical discomfort [7,10,11], which can negatively affect the work and employees' quality of life [12]. Office workers may not lift heavy weights or move in unergonomic positions, but show sedentary behaviors that correlate with lower back [13] and neck pain [14].…”