Table 5 Multivariable analysis of the ergonomic predictors of work-related musculoskeletal disorders
Ergonomic factors | Self-reported WRMSDs in the past 12 months (%) | Unadjusted Model | Adjusted model | |||
|---|---|---|---|---|---|---|
Yes (n = 49) | No (n = 147) | PR | [95% CI] | PR | [95% CI] | |
Age in years | ||||||
  < 30 | 9 (24.3) | 28 (75.7) | 1 |  |  | 1 |
 30–34 | 12 (22.2) | 42 (77. 8) | 0.91 | [0.43, 1.95] |  | 0.94 (0.39, 2.25) |
 35–39 | 8 (16.7) | 40 (83.3) | 0.69 | [0.29, 1.61] |  | 0.78 (0.28, 2.18) |
  ≥ 40 | 20 (35.1) | 37 (64.9) | 1.44 | [0.74, 2.82] |  | 2.04 (0.96, 4.37) |
Level of education | ||||||
 Primary | 5 (29.4) | 12 (70.6) | 1 |  |  | 1 |
 Secondary | 18 (21.7) | 65 (78.3) | 0.74 | [0.32, 1.72] |  | 0.39 (0.18, 0.85) * |
 Tertiary | 24 (25.5) | 70 (74.5) | 0.87 | [0.38, 1.96] |  | 0.81 (0.42, 1.57) |
Experience | ||||||
 1–5 years | 29 (20.4) | 113 (79.6) | 1 |  |  | 1 |
  > 5 years | 20 (37.0) | 34 (63.0) | 1.81 | [1.13, 2.92]* |  | 1.23 (0.73, 2.07) |
Duration of the Shifts | Â | Â | Â | Â | Â | |
  ≤ 9 h | 2 (6.1) | 31 (93.9) | 1 |  | 1 |  |
  > 9 h | 47 (28.8) | 116 (71.2) | 4.76 | [1.21, 18.69] * | 3.56 | [1.76, 16.58] * |
Heavy/frequent lifting / lowering / shoveling | ||||||
 No exposure | 17 (24.6) | 52 (75.4) | 1 |  | 1 |  |
 Caution | 15 (16.3) | 77 (83.7) | 0.66 | [0.36, 1.23] | 0.50 | [0.27, 1.04] |
 Hazard | 17 (48.6) | 18 (51.4) | 1.97 | [1.15, 3.37] ** | 1.69 | [1.32, 3.24] * |
Awkward postures | ||||||
 No exposure | 9 (18.8) | 39 (81.28) | 1 |  | 1 |  |
 Caution | 15 (19.2) | 63 (80.8) | 1.03 | [0.49, 2.16] | 1.38 | [0.67, 2.86] |
 Hazard | 25 (35.7) | 45 (64.3) | 1.90 | [0.98, 3.72] | 1.26 | [0.63, 2.54] |
High hand force | ||||||
 No exposure | 15 (25.9) | 43 (74.1) | 1 |  |  |  |
 Caution | 11 (17.5) | 52 (82.5) | 0.68 | [0.34, 1.35] |  |  |
 Hazard | 23 (30. 7) | 52 (69.3) | 1.19 | [0.68, 2.06] |  |  |
Highly repetitive work | ||||||
 No exposure | 18 (20.9) | 68 (79.1) | 1 |  |  |  |
 Caution | 18 (27.3) | 48 (72.7) | 1.30 | [0.74, 2.31] |  |  |
 Hazard | 13 (29.6) | 31 (70.4) | 1.41 | [0.76, 2.61] |  |  |
Vibrating tools | ||||||
 No exposure | 23 (20.5) | 89 (79.5) | 1 |  |  |  |
 Caution | 12 (24.0) | 38 (76.0) | 1.17 | [0.63, 2.16] |  |  |
 Hazard | 14 (41.2) | 20 (58.8) | 2.01 | [1.16, 3.45] ** |  |  |
Bouncing | ||||||
 No exposure | 21 (19.6) | 86 (80.4) | 1 |  |  |  |
 Caution | 9 (24.3) | 28 (75.7) | 1.24 | [0.62, 2.46] |  |  |
 Hazard | 19 (36.5)) | 33 (63.5) | 1.86 | [1.10, 3.15] * |  |  |
Static postures | ||||||
 No exposure | 10 (16.1) | 52 (83.9) | 1 |  |  |  |
 Caution | 22 (31.0) | 49 (69.0) | 1.92 | [0.99, 3.74] |  |  |
 Hazard | 17 (27.0) | 46 (73.0) | 1.67 | [0.83, 3.37] |  |  |
Pushing and pulling | ||||||
 No exposure | 21 (22.3) | 73 (77.7) | 1 |  |  |  |
 Caution | 20 (28.2) | 51 (71.8) | 1.26 | [0.74, 2.14] |  |  |
 Hazard | 8 (25.8) | 23 (74.2) | 1.16 | [0.57, 2.34] |  |  |