This study was carried out in a slaughterhouse in Zagazig City during the year 2005-2006 among a group of 115 slaughterhouse workers selected randomly and performing sustained intensive manual work. Another group of 80 clerks working in Zagazig Faculty of medicine performing light manual work was selected randomly as a control group. The study was done in 2 stages : The 1st stage was a comparative cross-sectional study, aiming to determine the prevalence of shoulder impingement syndrome ( SIS) among the study workers.The 2nd stage was an intervention study, done to assess the effect of exercise and manual physical therapy program on shoulder function among workers with shoulder
impingement syndrome. A total number of one-hundred and ninety five workers were interviewed using a preconstructed questionnaire. Those workers who had recurrent 143 Egyptian Journal of Occupational Medicine, 2007; 31 (1) : 143 - 162
144 El-Laithy N. et. al shoulder pain during the previous 3 months or more were subjected to standardized
physical examination using impingement sign, assessment of shoulder function and magnetic resonance imaging to those clinically diagnosed as SIS. Also an intervention program of exercise and manual therapy for a period of 6-weeks was carried out to those workers with SIS.he results revealed that the prevalence of SIS was higher among the laughterhouse
workers (13.9 % ) compared to the control workers(2.5%). SIS symptoms and signs were more frequently recorded among the slaughterhouse workers when compared with the controls. Also among those currently complaining of SIS symptoms or those who has had SIS signs, only 15.6% and 2.5% have positive impingement sign among slaughterhouse workers and their controls respectively. The most reliable findings of magnetic resonance imaging were the presence of
indentations upon the subacromial fat denoting impingement in 12 patients (66.7%),supraspinatus tendonitis with indentation upon subacromial fat denoting impingement in 4 patients (22.2%) & left supraspinatus tear in 2 patients (11.1%) from 18 slaughterhouse workers diagnosed clinically as SIS and supraspinatus tendonitis with impingement
in 2 patients (100.0%) from the control group with a total percentage of 13.9% and 2.5% workers with SIS among slaughterhouse workers and their controls respectively. Studying some personal and occupational factors thought to be related to the prevalence of SIS revealed that, SIS was prevalent in middle aged workers who smoke and were worked in the current occupation for more than ten years.The results of the intervention program illustrated that there were significant improvement in range of motion, pain, strength and function of the shoulder in workers with SIS after 6- weeks of exercise and manual physical therapy program.In conclusion, sustained intensive manual work such as in slaughterhouse workers was associated with high frequency of SIS. A 6 week exercise with manual physical
therapy program in patients with SIS was resulted in improvement of range of motion, pain and function of the shoulder. So, work organization especially reduction of exposure time and early intervention are needed in tasks in which there are combinations of force, repetition and sustained arm elevation.