When the requirements of work are such that a man can overcome them by making an effort, the functional ability of his body and his health are not endangered and there is ergonomic balance. In that sense, the physiology of work deals with:
o Defining the workload;
o Defining the requirements of work;
o Studying human physiological abilities and the size of physiological effort he can make in order to respond to the requirements of work.
(1) Defining the workload
Performing each work is a kind of a burden for the body. The type, intensity and duration of the load depend on the work. Physiological workloads should be such that the body can respond to them through physiological functions, i.e. to maintain homeostasis when working. The load that can not be overcome leads to disorders of homeostasis (the balance in the body is lost) which is an overload that causes fatigue. In case of further increasing the intensity of overload, there is a pathological response of the body, i.e. fatigue.
Loads can be physical, mental and sensory.
Physical work (the work of skeletal muscles) is a major cause of physical load because of work. Physical work means the work that a man does while overcoming the burden and resistance. Physical work can be dynamic and static work.
(2) Defining the requirements of work
Requirements of work define what the workload and adverse effects require from the organism of workers and can be the following:
- Requests for certain functions of the organism. In addition to general health conditions, the work requires some particularly preserved functions of organs and systems or some particularly preserved or marked morphological features of a man.
- Requests for certain age limits of a worker. Depending on the age, some functions are established, some are changed, some disappear or are reduced, so that the same work shall not place the same demands on quite young, middle-aged or older workers.
- Requests for a specific sex of a worker. These requirements are not common, and are based on specific differences in the physiology of female and male body.
(3) Size of physiological effort
A man must make an effort in order to deal with the load imposed by a certain work. The analysis of work can specify which functions of the body will be exposed to the influence of that work. So the individual workplace should always be analysed, not the occupation.
The bigger the load is, the bigger the effort is, although not all the people make the same effort to deal with the same load. In determining the effort, the following has to be determined:
- the limit of physiological strain at rest,
- the level of physiological response to work impact, and
- the boundary between physiological and pathological responses.
Read more: ERGONOMICS IN THE GARMENT INDUSTRY
