Physical workload

Although advances in technological capability and increased automation have reduced the level of physical workload imposed on control room operators, it is still a pertinent issue to consider during the design and assessment of process control rooms. 

FIG U RE 6.1 Factors affecting mental workload and the consequences associated with overload and underload. 

Physical workload represents the level of physical exertion or demand imposed on an operator by a task or process. According to Sanders and McCormick (1993), many factors contribute to the level of workload experienced by operators undertaking physical activity, including the nature of the work itself, somatic factors (e.g., age, sex), training, motivation, and environmental conditions (e.g., noise, heat). As with mental workload, various consequences are associated with inappropriate levels of physical workload. Too great a level of physical workload, and operators can become fatigued and overstressed too low a level of physical workload, and they can become bored or inattentive. 

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Differences among individuals can partially explain the differences in the before workshift and end of workshift levels of trichloroethylene and its metabolites. Increased respiration rate during a workday, induced by physical workload, has been shown to affect levels of unchanged trichloroethylene more than its metabolites, while the amount of body fat influences the levels of the solvent and its metabolites in breath, blood, and urine samples before workshift exposure (Sato 1993). Additionally, liver function affects measurements of exhaled solvent at the end of workshift increased metabolism of trichloroethylene will tend to decrease the amount exhaled after a workshift. Increased renal function would affect levels of TCA and trichloroethanol in blood before a workshift in the same way, but it probably would not affect urine values between the begiiming and the end of the workshift because of the slow excretion rate of TCA. 

Droz, P.O., and J.G. Fernandez. 1977. Effect of physical workload on retention and metabolism of inhaled organic solvents. A comparative theoretical approach and its applications with regards to exposure monitoring. Int. Arch. Occup. Environ. Health. 38(4) 231-246. 

Interactive Monitoring Studies of Emotional, Mental, and Physical Workload Components... 

Myrtek, M., Brugner, G., Muller, W (1996b). Validation studies of emotional, mental, and physical workload components in the field. In J. Fahrenberg M. Myrtek (Eds.). Ambulatory assessment Computer-assisted psychological and psychophysiological methods in monitoring and field studies (pp. 287 304). Seattle Hogrefe Huber. 

Mental and Physical Workload As Related to Stress Hormones... 

Finally, physical workload is concerned with the use of the medical device and adds to user stress. Under high stress, the users of medical devices are distracted and have less time to make decisions (e.g., consider multiple device outputs). 

A heavy physical workload presents a strong risk for hip and knee osteoarthritis (OA), especially for... 

Designers should recognize that operators are not inherently flawed and subsequently should not simply remove or automate as many tasks as possible. This approach is likely to lead to mental underload and could leave operators with incoherent sets of tasks. The goal instead should be to design the system and procedures to exploit the skills of human operators. Physical workload should be kept to a minimum, whereas mental workload should be optimized. Ways to optimize mental workload include the use of adaptive interfaces (systems that can detect periods of elevated workload and then assist the operator accordingly) and dynamic allocation of function (systems that relieve the operator of task elements during high workload portions of the task). 

An abundance of human factors literature surrounds the area of physical workload however, for obvious reasons, very little research has focused on the level of physical workload imposed on process control room operators. The type of manual tasks investigated within the context of physical workload include lifting, pushing, and pulling types of tasks, most of which are not required in contanporary control rooms. 

The forest establishment operations such as semi-mechanized hole digging and terrain cleaning presents a number of ergonomic problems such as high physical workload, high noise and vibration levels, high demand of strength, forced postures, lack of pauses and repeatability of movements. 

PW Physical workload Rep Repetitiveness Vb Vibration TE Thermal environment. ... 

The tasks performed by them have a bigger mental than physical workload. All protocols of Comite de Etica na Pesquisa (Research Ethics Committee) were attended according to Resolufoo 466112 of Conselho Nacional de Saude—BR. 

Minor physical workload Gifting and carrying loads) Major physical workload Gifting and carrying loads)... 

Job description/physical workload, for example, static muscle load, lifting and moving loads, sudden load increase, repealed inappropriate and unacceptable moves... 

Biological monitoring is limited by parameters that can affect the exposiue and dose relationship. Such parameters include the following biological conditions (age, sex, obesity, pregnancy, disease), physical workload, or exposure to other agents (other chemicals, tobacco smoking, dietary components) that in some way interfere with the uptake, distri-... 

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