Abstract The main purpose of the study was to investigate the prevalence of perceived symptoms of musculoskeletal disorders (MSD) among workers on large-scale dairy and pig farms in Sweden (herd size more than 300 cows and 450 sows) and to identify potential risk factors in the development of MSD. A study based on questionnaires was carried out among 42 workers on 10 large dairy farms and among 37 workers on 10 large pig farms in Southern Sweden during the autumn of 2002. Most importantly, the study showed that 86% of the dairy workers and 78% of the pig workers reported some kind of MSD during a period of 12 months prior to the study. The most frequently reported MSD among both the dairy and the pig workers were in the “upper extremities” (52% and 62%, respectively) especially in the shoulders and in “the back” (60% and 57%, respectively) especially in the lower back. Furthermore, being of short stature, doing repetitive work, working in awkward positions and being exposed to dust were significant risk factors in having MSD among the workers in this study. Thus, working with many cows and sows on large-scale farms in Sweden can be considered as a high risk job with regard to MSD. Key Words: Agricultureanimal farmingdairy productionpig productionfarmersfarm workerswork environmentmusculoskeletal disordersquestionnairerisk factors
The aim of the study was to quantify the workload on the upper extremity for fundamental work tasks during machine milking. Eleven milkers working in a loose-housing system with a milking parlour participated in the study. Muscle activity for the biceps and the forearm flexors, as well as positions and movements of the wrists were simultaneously measured by electromyography and electrogoniometry while video-recording the work. The milking work was broken up in three main tasks "Drying (the cow's udder)", "Pre-milking (the first milk)" and "Attaching (the milking unit to the udder)" and three supplementary tasks. All three main tasks show high muscle load values and almost no time for rest. The highest load values for the biceps and flexor muscles were found during the tasks "Attaching, holding the milking unit" and "Drying", respectively. For 10% of the recording time, the milkers held active hands in 42 degrees dorsal flexion during the milking tasks "Pre-milking" and "Attaching" and in deviated positions exceeding 50% of their maximum values during "Attaching" and "Drying". The high muscle loads in combination with extreme positions and movements of the hand and forearm might contribute to the development of injuries among milkers. The result from the study aims to form a basis for technical improvements of the milking equipment to decrease the risk for arm wrist and hand disorders.
The prevalence of and the impact of selected factors on self-reported musculoskeletal complaints in Swedish female milkers with special reference to symptoms in the upper extremities were investigated using data from mail-in surveys. An agricultural study group was formed of three subgroups: 161 active milkers, 108 non-milkers and 62 ex-milkers, women who had been milkers earlier but were no longer doing that kind of work. In the course of the analysis these subgroups were compared with each other and also, separately or in combinations, with a non-agricultural population consisting of 166 nursing assistants. Problems in the upper extremities were significantly more common in the agricultural group than in the non-agricultural group. Milkers ran a higher risk of developing symptoms in the wrists and hands than non-milking women. Symptoms such as numbness, coldness in the wrists and white fingers were more common in all agricultural subgroups than in the non-agricultural group. Numbness and white fingers were related to vibration exposure in the ex-milker and the non-milker groups but not in the milker group. Psychosocial factors such as occupational well-being were not related to the occurrence of symptoms. Milking in a modernized barn gave fewer problems in elbows than milking in a traditional barn. Milkers who had received ergonomic instruction on how to work in order to reduce muscle stress had fewer problems in the elbow region than those who had received no such information.
Pronator syndrome (median nerve entrapment at the elbow) is a rare condition, but it is more common among women than men. A long-term retrospective follow-up study evaluating the outcome of surgical release of the median nerve for female machine milkers has never been carried out before, nor has a long-term study of non-treated female milkers with pronator syndrome. In the present study, two groups of machine milkers (surgical and non-surgical) were compared. The clinical examination focused on two parameters: focal tenderness and individual muscle strength. The results showed that the surgical group had no focal tenderness on palpation over the median nerve at the elbow and no selective weakness in the muscles examined, as compared to what was found before surgery. In the non-surgical group, focal tenderness was found in 12 out of 14, and 10 out of 14 showed the same weakness as in an earlier examination. While this study has limitations in sample size, surgical release of the median nerve at the elbow level, in cases of pronator syndrome, appears to provide an immediate as well as long-term return to normal strength of FPL and FDP II, along with a significant improvement in subjective status. In the non-surgical group, spontaneous improvement of the strength of FPL and FDP II was found in only four out of the 14 cases.
With the use of electrogoniometers wrist positions and movements were measured in 13 milkers while working in a modern rotary milking system. The rotary system put considerable demands on the wrists and hands regarding both velocities and repetitiveness. Values were found close to those described in other repetitive industrial work with high risk of wrist and hand disorders. For the right hand the repetitiveness was 0.57 Hz and 0.46 Hz for the left hand. In addition, the median value (50th percentile) of the angular velocity distribution was also high, being 36 degrees /s for the right hand and 26 degrees /s for the left, and with respect to the peak value (90th percentile) the corresponding values were 155 degrees /s and 135 degrees /s, respectively. Furthermore, when milking in the rotary system, there was less possibility to hold the hands still than in the other milking systems. The right hand rested only 1.4% of the milking time and the left only 1.0%. The hands were therefore moving throughout almost the entire milking procedure. High velocity, repetitiveness and fewer opportunities for rest are risk factors that might lead to disorders in the wrists and hands. Regarding wrist positions, the left wrist was held in a more dorsiflexed position than the right, 37 degrees and 29 degrees, respectively. Compared with tethering and loose-housing parlour milking, the wrist positions were, however, improved in the rotary system. When introducing new milking systems these negative effects on wrist and hand movements must be borne in mind in order to minimize the prevalence of wrist and hand disorders.
ABSTRACT When milking cows that are kept in stanchion barns, the milker has to use various working postures and movements that involve walking, sitting, rising, squatting, kneeling, stooping, bending, twisting and stretching. They must do this while holding a load of 3-6 kg (cluster, teat cups) in one hand under the cow's udder at a relatively long distance from the body. This is the usual working situation for most farmers and farm workers in Swedish dairy production. Only 5 per cent of the seventeen thousand Swedish dairy farms have any type of loose-housing system with parlor milking, which reduces a lot of the ergonomic stress. An increasing number of the milkers and the relief personnel now working in dairy farming are young women who may have less physical strength than men. Much additional research is needed to obtain the data necessary for the planning of safer and better dairy barns, in which the average man or woman can work. This paper is a review of research conducted over the past 20 years, with analysis and recommendations.
Results from a questionnaire survey among riding-instructors showed that perceived symptoms most frequently were reported in the neck (52 %), the shoulders (60 %) and in the lower back (56 %) during the past 12 months. 91 % of the riding instructors reported symptoms from at least one of nine anatomic areas the past 12 months. The prevalence is high considered that the median age was 33 years. Mucking out was considered to have the highest work load among the work tasks. The most time consuming work task were riding lessons.
