1. Occupational risk factors for osteoarthritis of the knee: a meta-analysis 
D.F. McWilliams, B.F. Leeb, S.G. Muthuri, M. Doherty, W. Zhang 
Osteoarthritis and Cartilage 
Volume 19, Issue 7, Pages (July 2011)
DOI: /j.joca
Copyright © 2011 Osteoarthritis Research Society International Terms and Conditions

2. Fig. 1 Flow diagram of study selection.
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2011 Osteoarthritis Research Society International Terms and Conditions

3. Fig. 2
Funnel plot of occupational risks for knee OA. Funnel plot showing all studies of knee OA and occupation. Asymmetry suggests publication bias. Egger test for bias=2.39, P<
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2011 Osteoarthritis Research Society International Terms and Conditions

4. Fig. 3
Forest plot showing all occupation and knee OA studies grouped by design with sub-totals shown for each type (cohort, cross-sectional and case control), and arranged in chronological order within each group.
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2011 Osteoarthritis Research Society International Terms and Conditions

5. Forest plot of studies of occupational risks for persistent knee pain in those over 40 years old. Knee OA studies were not included.
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2011 Osteoarthritis Research Society International Terms and Conditions