As far as we know, there is no epidemiological evidence for an association between lifting and carrying and shoulder symptoms. However, PLX-4720 mouse several studies reported significant associations between pushing and pulling and shoulder symptoms

(Van der Beek et al. 1993; Hughes et al. 1997; Hoozemans et al. 2002a, b; Harkeness et al. 2003; Smedley et al. 2003). Not taking into account pushing and pulling as a potential risk factor or confounder may partly explain the observed differences in odds ratio’s (ORs) between exposure in terms of occupational groups (Table 2; Seidler et al. 2011) and in terms of strenuous activities (Table 3; Seidler et al. 2011). For instance, for construction workers, packers and physically exposed service workers (f.i. nurses

and refuse collectors), Seidler et al. (2011) observed significant adjusted ORs of 2.5, 5.0 and 1.9, respectively. These ORs are somewhat higher than for lifting and carrying, which may be caused by the fact that jobs that consist of manual materials FDA-approved Drug Library handling often BMS345541 solubility dmso include pushing and pulling besides lifting and carrying (Baril-Gingras and Lortie 1995). For comparable jobs, Hoozemans et al. (2002a) reported significant prevalence rate ratios (PRRs) for shoulder symptoms between 2.2 and 4.9 for self-reported and observed exposure to pushing and pulling in their 1-year prospective cohort study among 829 workers. In this study, the PRRs were adjusted for working above shoulder level and lifting and carrying. These findings are supported by biomechanical studies on contact

forces at the glenohumeral joint in jobs like service workers in distribution (Hoozemans et al. 2004) and Erythromycin refuse collectors (Kuijer et al. 2003). Therefore, we strongly recommend taking into account pushing and pulling when evaluating manual materials handling, especially in relation to shoulder symptoms (Kuijer et al. 2007). Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited. References Baril-Gingras G, Lortie M (1995) The handling of objects other than boxes: univariate analysis of handling techniques in a large transport company. Ergonomics 38:905–925CrossRef Harkeness EF, Macfarlane GJ, Nahit ES, Silman AJ, McBeth J (2003) Mechanical and psychosocial factors predict new onset shoulder pain: a prospective cohort study of newly employed workers. Occup Environ Med 60:850–857CrossRef Hoozemans MJ, van der Beek AJ, Fring-Dresen MH, van der Woude LHV, van Dijk FJ (2002a) Low-back and shoulder complaints among workers with pushing and pulling tasks. Scand. J Work Environ Health 28(5):293–303 Hoozemans MJ, van der Beek AJ, Frings-Dresen MH, van der Woude LHV, van Dijk FJ (2002b) Pushing and pulling in association with low back and shoulder complaints.