An electromyography study in three high risk poultry processing jobs

This paper presents the results of a muscle load study of poultry processing operators performing three different jobs: basket packing, cutting/packing and trimming. Eighteen operators participated in this study. Surface electromyography (EMG) was recorded From bilateral upper trapezius, right forearm flexor and extensor muscles during the job performance. Results showed high muscle loads of the forearm flexor and extensor muscles for the operators 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 upper trapezius muscles in some individuals. The job of cutter,;packer had significantly higher trapezius loads, while trimmer operators had significantly higher peak forearm flexor and median extensor loads than the other jobs. Lack of ergonomic consideration of workstation designs mag: be one of the reasons causing the high trapezius loads for some of the cutting/packing operators and basket packers. Repetitive pinching operations and the frequent use of knives in cutting may be a major contributing factors causing high forearm muscle loads. An efficient knife sharpening program or alternative cutting methods (mechanical knives or scissors), modified processing procedures in order to reduce the pinching effort, and properly adjusted workstation may be able to improve the muscle loading conditions for the high risk poultry processing jobs.