Standing and kneeling as risk factors in knee disorders

ABSTRACT

To determine the prevalence of knee disorders in some occupations possibly related to work positions that put strain on the knees. A cross-sectional study has been carried out on 46 floor layers and 38 carpenters who were exposed to knee straining at work as well as 48 clerks whose work does not strain the knees. The members of the study were interviewed using a questionnaire including personal, occupational and past histories and present knee complaints. They were subjected to clinical examination of the knees and workers who reported knee complaints were subjected to radiological imaging. The prevalence of knee complaints was significantly higher among floor layers [47.8%] and carpenters [34.2%] than among clerks [14.6%]. 28.3% of floor layers and 10.5% of carpenters had changed work tasks or working methods because of knee complaints. The prevalence of bursitis was significantly higher in floor layers [17.3%] as compared to clerks [2.08%] while there was no significant difference between carpenters and clerks as regard bursitis. The prevalence of hyperkeratosis was significantly higher in floor layers [58.7%] and carpenters [36.8%] as compared to clerks [14.6%]. The prevalence of knee osteoarthritis was significantly higher in floor layers [77.2%] as compared to clerks [28.5%], while there was no significant difference between carpenters and clerks as regard knee osteoarthritis. Comparison between clinical signs and radiological knee osteoarthritis showed no significant association between radiological knee osteoarthritis and intra-articular and retropatellar crepitation while there was no association with pain caused by knee bending. Risk factors of knee osteoarthritis were found to be occupation, obesity and duration of work. Work in which a considerable amount of time is spent in knee straining positions, as floor layers and carpenters, causes more self reported knee complaints and contributes to the development of knee disorders and osteoarthritis