The relationship between heart rate as an indicator of work hardness and results of dynamometry

Heart rate is associated with work hardness and increase linearly with its increasing. In the average of energy consumption, heart rate measurement is simple but non-accurate method for calculation of work hardness. Our purpose in this research was to evaluate the relationship between heart rate and dynamometry results with hypothesis of work hardness effectiveness on the human power. This study was conducted on 102 porcelain workers. Participants were selected randomly. The research tools include stethoscope, the dynamometer. Heart rate, and pinch, grip, and back-leg-chest force were measured and relationships between variables were analyzed with Pearson correlation test and independent T-test using Spss 16 software. The average heart rate of participants were 4.11 ± 1.79 with minimum 60 and maximum 120. The average force of pinch, grip, and back-leg-chest were 8.9 ± 3.20, 4.2 ± 4.5 and 9.36 ± 6.55, respectively. Work hardness for 3.86% of workers were light, 7.12% were moderate and 1% were heavy. Pinch, grip, and back-leg-chest force relation with heart rate were not significant (r=0.01, p=0.85), (r=-0.03, p=0.74), and (r=0.05, p= 0.59), respectively. There was no correlation between heart rate and work hardness. So we can't use the dynamometry results to determine of work hardness.     

Study on workloads of human care worker with the introduction of IT system - the characteristics of work loads by observational research and the suggestions for KAIZEN

The purpose of this study was to clarify the characteristic of workloads on human care worker with the introduction of IT system, and suggested the support measures for KAIZEN in Japan. The investigation method is workflow line and hearing with a focus on work observation. The objects were 8 human care workers of the acute hospital that introduced an electronic system. By the introduction of the electronic chart, the nurse station sojourn time decreased, sickroom sojourn time increased, and time about direct nursing care to a patient increased. In addition, access to patient information became easy, and the offer of the health care service based on correct information came to be possible in real time. By The point of workflow line, it was effect that moving lengths decreased in order to install the electronic chart in patients' rooms. Though, it was a problem that it hasn't formed where to place the instruments such as sphygmomanometer, clinical thermometer and others.     

Consolidated findings from 6 years research on the age-differentiated design of human-computer interaction

The fast aging of many western and eastern societies and their increasing reliance on information technology create a compelling need to reconsider older users' interactions with computers. This paper summarizes the results of 6 years of research on the age-differentiated design of human-computer interaction. The well-known model of human information processing served as the theoretical framework. The model components 'sensory processing', 'perception', 'working memory', 'decision and response selection' and 'response execution' were analyzed exemplarily in task settings on project management. In seven empirical studies with a total number of 405 participants between 20 and 77 years the human-computer interaction was analyzed regarding effectiveness, efficiency and user satisfaction. For most but not all studies the results reveal that age-induced differences in human-computer interaction can best be compensated by an ergonomic 'design for all'. In some cases however an age-specific approach is favorable.     

Relationship between construction workers' musculoskeletal disorders and occupational health service activities

Construction work consists of numerous factors that influence workers' occupational health and that load the musculoskeletal system in particular. Musculoskeletal disorders are responsible for over a third of all sick leaves lasting over nine days in the construction industry. Occupational health services (OHS) were organized for 85% of the construction workers in our study. The proportion of construction workers who had suffered from chronic or repetitive neck and shoulder, shoulder or arm, or low-back disorders was 55.6%, 44.8% and 42.1%, respectively. Those who felt that they had received enough information, advice or guidance from OHS concerning work posture, work performance or work tools were more often those who had not suffered from shoulder or arm disorders (60.9% vs. 39.1%, p=.024, respectively) or low-back disorders (63.6% vs. 36.4%, p=.034, respectively) during the last month than those who had. Those who had received enough support from OHS concerning maintenance of work ability were more often workers who had not suffered from low-back disorders during the last month than those who had (63.3% vs. 36.7%, p=.004, respectively). OHS should focus more on workers who would really benefit from their activities at a particular time and in a particular situation (primary, secondary or tertiary prevention) and who are themselves devoted to improving their health.     

Naturalistic observation of drivers' interactions while overtaking on an undivided road

Current models of driving behavior and designs of driver support systems are not taking adequately into account the interactions between drivers. Although a driver's intended maneuver may not be physically possible at a specific time point, it may still be safely executed if the driver's intention is successfully communicated to and interpreted by another driver, who alters the own future trajectory so as to enable the maneuver execution. This paper presents some empirical findings relevant to communicative and cooperative interactions between drivers along naturalistic overtaking maneuvers on an undivided road. The cues used by drivers to interpret other drivers' intention and the drivers' interactions were extracted through video observations of the maneuvers together with the frequency of such interactions per level of traffic risk. The findings show that drivers use formal and informal cues to anticipate other drivers' intention. A significant percentage of maneuvers were performed after facilitation by other drivers. Future studies should focus on this phenomenon while future models of driving behavior should incorporate communicative and cooperative interactions among drivers, so as to design adequate cooperative support systems to enhance road safety.     

Impact of lightweight and conventional jackhammers on the operator

Jackhammer manufacturers have recently developed lightweight (45-60 lbs) jackhammers intended to reduce the required lifting and pushing forces during operation. However, the vibration characteristics of the lightweight jackhammers and their effect on muscle activity are currently unknown. The objective of this study was to compare the measured vibration and muscle activity between: (i) conventional (90 lb) and light weight (60 lb) jackhammers, (ii) different pavement type/thickness combinations, and (iii) pneumatic and hydraulic jackhammers. Five jackhammers were tested on 4 and 6 inch thick asphalt and concrete pavements by four experienced operators. Analysis of the results revealed that both weight classes averaged 9.7 m/s(2) at the 20 Hz weighted 1/3 octave band frequency, and the TLV of daily exposure for either weight class of jackhammer was less than 1.5 hours/per day. There was an approximately 33% difference in vibration measured on the hand of the operators due to pavement thickness, 30% due pavement type, and no difference due to power source. Conventional jackhammers overall produced higher muscle activity than lightweight jackhammers. Although selection of the correct jackhammer for the job involves many factors including pavement type and thickness, the results of this research can be used to assist in selecting the appropriate jackhammer.     

Casting an ergonomic eye on university libraries

Research in the field of Ergonomics of the Built Environment has been developed with a view to consolidating studies in this area, the objective of which is to provide evidence that the joint participation of users and designers on drawing up projects is important. In this context, the theme of this study is to investigate the interactions between users and the environment in a university library. To do so, well-established techniques from Ergonomics, Architecture and Environmental Psychology were used to make a functional and behavioral evaluation to identify the level of user satisfaction in six libraries in the various study centers of the Federal University of Pernambuco in Recife, northeast Brazil, so as to identify the strengths and also weaknesses in these spatial structures.     

Ergonomic basket design to reduce cumulative trauma disorders in tea leaf plucking operation

Work related musculoskeletal disorders are seen as an indicating parameter of occupational stress among the women workers engaged in tea leaf plucking operation. The hand plucking (no mechanized plucking is practiced in Assam) being a highly repetitive task requires forceful exertions to reach to the distant periphery of the tea bushes and mechanical compression (pressing against hard surfaces). Specifically it aggravates with awkward positions adopted. The current research addresses to minimize the risk factors associated with CTDs and to ascertain the role of ergonomic design development in improving the situation. Women workforce engaged in tea industry in Assam suffer from back, shoulder, arm and finger pains. Workers perform the activity for 440 minutes in the entire shift with one hour lunch break in between in the garden itself. An ergonomic investigation aiming at studying the strain index of plucking operation in tea industry was conducted. While performing the operation workers were found to assume unnatural posture which is static as well as highly dynamic with a load (tea leaf collecting basket up to weight of 30 kg when filled with plucked leaves) at back. With gradual increment of load and pain though the load is released intermittently the strain level found to remain at a high level. The total QEC scores found for plucking activity was 110 out of 138. To improve the situation and to reduce the work related upper limb disorder (WRULD) an ergonomically designed basket was conceived and trial results showed improvements. The newly designed plucking basket fits the back curvature of the workers well, which keeps the basket in place unlike the existing round basket. The new basket is light in weight having more leaf capacity. Significant reduction in energy expenditure and MSDs suffered was observed while using improved basket over existing basket.