An EMG-study of work methods and equipment in crane coupling as a basis for job redesign

Previous studies have shown that physical strain is perceived as the main work environment problem for crane couplers. During one year, 70% of the crane couplers at two Swedish steelworks (n = 124) indicated complaints of the locomotor system. An experimental field study comprising seven healthy female crane couplers was therefore carried out to determine if crane coupling implies too high a physical strain for healthy individuals, and to suggest ergonomics solutions to such problems if they occur. The significance of using different methods and equipment for reducing physical strain was evaluated by vocational EMG (four shoulder/neck and arm muscles), heart rate and ratings of perceived exertion. The data suggest that crane coupling may have harmful effects on the shoulder/neck. The investigated changes in work methods and equipment reduced the peak loads. If the crane coupler also has to operate the crane by radio control, this implies a rationalisation as well as a reduction in strain.