Die verband tussen fisieke vermoëns, veroudering en werkspesifieke taakprofiele van manlike werkers in 'n elektrisiteitsvoorsieningsmaatskappy

Abstract

1. Problem and purpose of this research The modem industry shows a progressive ageing workforce (Hale, 1990: 15- 17; Warr, 1993:238; De Swart et al., 1995:l; Shephard, 1997:325). This trend relates to workers that do not possess the necessary physical ability required by the work tasks (Bernauer & Bonanno, 1975%'; Fraser, 1992: 1). Several researchers (Hale, 1990: 16; WGO, 1993:l; Ilmarinen et al., 1997:55; Shephard, 1997:333) regard this physical inability of workers to perform physical intensive tasks as an important contributor to the increase in work related injuries. Employers implement several programs and procedures to ensure the health and safety of workers and to improve productivity. One of these procedures is evaluating the physical ability of workers according to the demands of their work tasks which is called task profiles (Fraser, 1992:l). The aim of this study was firstly to determine the extent to which the physical ability of workers differ from their task profile demands and secondly to determine the effect of ageing on the physical ability and task profiles of workers. 2. Method of research The study was performed on all male workers (3676 participants) performing physical demanding tasks in an electricity supply company in South Africa. The workers were assessed according to the physical task profiles developed by the company for all workers performing physical demanding tasks. These physical components were: flexibility, cardio-respiratory endurance, grip muscle strength, leg muscle strength, back muscle strength; arm-/shoulder muscle strength and abdominal muscle endurance. Each one of the workers' assessed was compared to the minimum requirement of his task profile for all eight physical parameters to determine if his physical ability met the requirement of the task demands. The workers were further grouped into 4 age groups namely: younger than 35, 36-45, 46-55 and older than 55 years to determine if ageing has an impact on the physical ability of workers to meet the requirements of their task profiles. Statistical analyses were performed using one way analysis of variances (ANOVA) and the measurements of Cohen to determine practical significance (Thomas & Nelson, l99O:l34). 3. Results The following is a summary of the results found: 3.1 The average physical ability of workers for each of the physical parameters does not significantly differ from their task profile demands. However, leg muscle strength, back muscle strength and abdominal muscle endurance had the highest number of workers that do not meet the requirements of their task profiles. None of these physical parameters, however, differed practical significantly from the task profile demands. 3.2 A practical significant number of workers had at least one physical parameter not meeting the task profile demand. 3.3 Workers could be identified with an accumulative number of their physical parameters not meeting the task profile demands. Even workers with all eight physical parameters weaker than the task profile demands, could be identified. 3.4 Most of the physical parameters weakened with ageing of the workers. Grip muscle strength, back muscle strength and abdominal muscle endurance showed practical significant deterioration with ageing, while arm-/shoulder, and leg muscle strength showed a moderate effect with ageing (practically not significant). Flexibility and cardio respiratory endurance where not affected with ageing. 3.5 The percentage of workers whose physical parameters did not meet their task profile demands increased with ageing. Irrespective of these relationships abdominal muscle endurance was the only physical parameter that showed a practical significant weakening with ageing. It is thus evident that in most instances ageing has no significant effect on the physical ability of workers according to their task profile demands. 3.6 Linear effects were observed between the accumulative number of physical parameters that did not meet the task profile demands and ageing. These effects were, however, not practical significant but did indicate an increase in the number of workers with more than one physical parameter that did not meet their task profile demands with the increase in age.