An electromyography study in three high risk poultry processing jobs

This paper presents the results of a muscle load study of poultry processin g operators performing three different jobs: basket packing, cutting/packin g and trimming. Eighteen operators participated in this study. Surface elec tromyography (EMG) was recorded From bilateral upper trapezius, right forea rm flexor and extensor muscles during the job performance. Results showed h igh muscle loads of the forearm flexor and extensor muscles for the operato rs conducting all three jobs. The static loading for both trapezius muscles was low (< 1% MVC). However, the peak load could be up to 24% MVC on the u pper trapezius muscles in some individuals. The job of cutter,;packer had s ignificantly higher trapezius loads, while trimmer operators had significan tly higher peak forearm flexor and median extensor loads than the other job s. Lack of ergonomic consideration of workstation designs mag: be one of th e reasons causing the high trapezius loads for some of the cutting/packing operators and basket packers. Repetitive pinching operations and the freque nt use of knives in cutting may be a major contributing factors causing hig h forearm muscle loads. An efficient knife sharpening program or alternativ e cutting methods (mechanical knives or scissors), modified processing proc edures in order to reduce the pinching effort, and properly adjusted workst ation may be able to improve the muscle loading conditions for the high ris k poultry processing jobs.