Musculo-skeletal stress suffered by linemen

Status:

completed 12/2005

Aims:

The particular conditions of overhead linemen working on high poles give rise to extreme physical work loads. As they climb the pole and also during fitting and maintenance work on the pole and work on the ground, overhead linemen adopt ergonomically unfavourable postures which place high physical loads upon the musculo-skeletal system. The physical work loads are a common complaint of all overhead linemen, and are reflected in the high number of working days lost through incapacity for work. An ergonomic analysis of work shifts was conducted with the objective of producing dedicated physical work load profiles for particular occupations and of identifying ergonomically critical tasks and working conditions. From the findings, preventive measures were to be formulated concerning the work equipment, organization of work, and behavioural prevention, in order to eliminate enforced early retirement from the occupation.

Activities/Methods:

Video sequences of activities performed by overhead linemen were recorded by the BG Institute for Occupational Safety and Health (BGIA) in order to identify problem areas and key sources of high physical work loads. The CUELA measurement system was then adapted to the long-term recording of physical work load profiles of overhead linemen. Besides the measurements of movements conducted with the CUELA system, electromyographic recordings were produced of selected muscle groups in the back and upper arms. Pulse measurements and electrocardiograms were also taken for assessment of the stress upon the cardiocirculatory system. Quantitative work load analyses were conducted using these methods in a field study over the whole- and half-day shifts of approximately 15 linemen. The tasks studied encompassed climbing, inspection, maintenance and repair work on high-voltage poles.

Results:

The results of the study reveal that the overhead linemen are exposed to considerable musculoskeletal loads during climbing and during the maintenance and fitting activity. During piecework, in particular, the stress upon the cardiocirculatory system is frequently in the anaerobic lactic acid range. Ultimately, the musculo-skeletal loads affect the entire body. Work performed in a constrained, ergonomically unfavourable posture, frequently in conjunction with the exertion of considerable force, constitutes the main problem. The conditions of the workplace environment offer only limited scope for ergonomic improvements to the working conditions. The focus of prevention lies upon improving and safeguarding the workers' physical capacity in a manner that can be achieved by selective training of cardiovascular endurance, muscular strength and flexibility. A preparatory phase is highly advisable before work is resumed following breaks lasting several weeks. The results are to be developed further in a follow-on project in which the findings are to be incorporated into a guidance document for companies. In addition to recommendations for preventive measures at the workplace, a catalogue of training exercises geared to the needs of overhead linemen is to be supplied to companies, in order for the workers in question to be trained in the exercises, ideally under skilled supervision, and subsequently to be able to perform them independently.

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