Fig. 1
Risk estimates among males and females of the included studies for a. cumulative tons of weights ≥20 kg handled, b. cumulative tons of weights ≥20 kg handled > 10 times / day, c. cumulative lifting and / or carrying operations of weights ≥20 kg and pooled risk increase (grey line). Legend: the circle size reflects the large [17], medium [26] and small [3, 5,6,7, 10] weights of the included studies in the meta-regression analysis. 1 Cumulative weight [in tons] lifted and/or carried, taking into account all weights ≥20 kg. 2 Cumulative weight [in tons] lifted and/or carried, taking into account all weights ≥20 kg that were handled at least 10 times per working day. 3 Cumulative number of lifting and/or carrying operations of weights ≥20 kg