The effect of tablet use on trunk posture while sitting

Assessment on Practicing Correct Body Posture and Determinant Analyses in a Large Population of a Metropolitan Area

An incorrect posture can generate stress of the spine and can be the cause of musculoskeletal disorders. Considering the extensive use of the computer, which worsens posture disorders, among workers, is important to analyze the phenomenon in order to reduce his impact on industry. The aim of this study is to assess determinants regarding posture in a large population of a metropolitan area. A total of 1177 questionnaires was analyzed. The majority of sample showed good knowledge and attitude regarding correct posture; most of the sample, 70.4% was aware of the definition of posture and 68.7% feel that not enough attention is paid at posture at workplace. Despite the good predisposition, only 2.8% of the sample consult a specialist for posture. The multiple linear regression analysis shows that those who have higher knowledge and best attitudes will consequently have good behaviors in maintaining a correct posture. Furthermore, age and education resulted main drivers of correct posture in any model considered. The results enlighten the necessity of conducting further studies to analyze attitudes of the general population and suggest improving educational and training programs to the enrichment of knowledge and to correct posture behaviors.

A comparative study of electronic and pen-paper safety inspections: A mixed method study design for assessing ergonomic parameters

BACKGROUND

Workplace inspections are applied to facilitate the adherence to the occupational health and safety regulations. The Iranian Ministry of Health introduced a new software system for tablets to inspect workplaces.

OBJECTIVES

The aim of this study was to take measurements of the usability, mental workload, and mood of inspectors.

METHODS

Inspectors used both pen-and-paper and tablet methods to inspect the automotive industry in a mixed-method procedure. The NASA-TLX score, QUIS score, I-PANAS (SF) situation, inspection time, and number of errors were collected throughout the procedure. The differences were investigated using a paired sample and the Wilcoxon signed ranks test.

RESULTS

In terms of efficacy, using the tablet resulted in lower error rates, but it took longer to complete the inspection task (P < 0.001). Participants perceived a lower workload when inspecting with a tablet rather than the traditional method. (Mental Demand: p < 0.002, Performance: p < 0.009, Effort: p < 0.012, TLX: p < 0.002 based on various subcomponents of NASA-TLX). The newly introduced system's usability was insufficient.

CONCLUSION

Although the use of tablets has improved safety inspections, ergonomic redesign of the system and consideration of a user-centered approach, as well as inspector training, can make the system more likely to succeed.

Physical activity, sitting time, neck disability and posture in workers using visual display terminals (VDT)

BACKGROUND

Musculoskeletal pain represents a major public health problem. Workers who use visual display terminals (VDT) have suffered an increase in neck pain in recent decades.

OBJECTIVE

The aim of this study was to analyze the relationship between physical activity (PA), sitting time, posture, and neck disability in a population of employed adults who use a computer at work.

METHODS

In this descriptive-correlational study, 88 workers with a mean age of 48.31 years participated. All of the participants filled out the Self-Report Habit Index (SRHI), International Physical Activity Questionnaire (IPAQ), and Neck Disability Index (NDI). The postural situation was also assessed with Posture Assessment Software (PAS/SAPO).

RESULTS

A significant and inverse relationship was observed between the habit of PA practice and the Body Mass Index (BMI). A total of 59.1% of the participants have a moderate PA index. There was a statistically significant relationship between the NDI and the time that workers spend sitting in a workday. A significance level of p≤0.05 was established for all the statistical analyses.

CONCLUSION

The increase in sitting time produces an increase in neck disability among workers and there are no significant differences between the level of PA and the cervical angles analyzed. The promotion of leisure-time PA and the reduction of prolonged uninterrupted sitting time at work could be one of the means to reduce musculoskeletal morbidity in the working population.

Reconstructing an accelerometer-based pelvis segment for three-dimensional kinematic analyses during laboratory simulated tasks with obstructed line-of-sight

Close interface between humans and inanimate objects (furniture, assistive devices, and external loads) can obstruct line-of-sight in biomechanics studies that utilize optoelectronic motion capture systems. This specific problem is frequently encountered with the pelvis segment. This study sought to compare joint and pelvis angles computed from a pelvis-fixed local coordinate system (LCS) that was constructed from optically tracked pelvis landmarks (gold standard) and landmarks derived from angular deviations calculated from triaxial accelerometer data. One participant performed seven tasks: sitting, forward bend, sit-to-stand-to-sit, forward lunge, symmetrical squat, asymmetrical squat, and gait. The root mean square error (RMSE) and coefficient of determination (R²) were examined for the pelvis, lumbar spine, and hip joint angles calculated using the standard and accelerometer-based methods for creating a LCS. The RMSE values for global pelvis angles ranged from 2.2° (gait; R² = 0.47) to 4.9° (sit-to-stand-to-sit; R² = 0.98), 0.6° (sitting; R² = 0.88) to 7.4° (gait; R² = 0.39), and 1.5° (forward bend; R² = 0.99) to 2.9° (sit-to-stand-to-sit; R² = 0.99) for motion about the X, Y, and Z axes, respectively. The magnitude of error observed for adjacent joint motion was lowest about the Z axis for all tasks. In conclusion, the accelerometer-based LCS offers an alternative method for computing pelvis and adjacent joint angles without the reliance on a visual line-of-sight. For motion about the X and Y axes, time-series data derived with the accelerometer-based method may be less representative of discrete events, particularly for gait and lunging tasks.