Table 2 Demographic and exposure characteristics of the study population

Sex

<  0.001

 Male

2815 (13.1)

18,647 (86.9)

 Female

3221 (16.7)

16,069 (83.3)

Age

<  0.001

  < 30

257 (6.2)

3896 (93.8)

 30–39

740 (9.1)

7312 (90.9)

 40–49

1425 (12.8)

9669 (87.2)

 50–59

1513 (16.2)

7804 (83.8)

  ≥ 60

2101 (26.0)

5975 (74.0)

Occupation type

<  0.001

 White collar

890 (7.0)

11,819 (93.0)

 Service workers

1862 (13.5)

11,950 (86.5)

 Blue collar

3284 (23.1)

10,947 (76.9)

Employment status

<  0.001

 Self-employed without employees

2510 (23.7)

8103 (76.3)

 Self-employed with employees

312 (13.1)

2077 (86.9)

 Paid workers

3214 (11.6)

24,536 (88.4)

Working hours (/week)

<  0.001

  < 40

1370 (20.7)

5243 (79.3)

 40–59

2953 (12.0)

21,736 (88.0)

  ≥ 60

1713 (18.1)

7737 (81.9)

Shift work

0.578

 Yes

445 (14.5)

2634 (85.5)

 No

5591 (14.8)

32,082 (85.2)

Number of employees

<  0.001

  < 5

3619 (19.3)

15,088 (80.7)

 5–49

1656 (11.2)

13,081 (88.8)

 50–299

537 (10.7)

4504 (89.3)

  ≥ 300

224 (9.9)

2043 (90.1)

Education

<  0.001

 Below elementary

1348 (32.6)

2786 (67.4)

 Middle & high school

3298 (16.6)

16,537 (83.4)

 Above university

1390 (8.3)

15,393 (91.7)

Income (10,000₩/month)

<  0.001

  < 100

1580 (23.6)

5127 (76.4)

 100–199

2138 (15.8)

11,429 (84.2)

 200–399

1898 (11.6)

14,454 (88.4)

  ≥ 400

420 (10.2)

3706 (89.8)

Rest during work time

<  0.001

 Always & most

2250 (16.4)

11,428 (83.6)

 Sometimes

3389 (13.6)

21,611 (86.4)

 Never

397 (19.1)

1677 (80.9)

Vibration exposure

<  0.001

 None

2164 (11.8)

16,180 (88.2)

 Mild

2785 (16.9)

13,653 (83.1)

 Moderate

665 (16.9)

3268 (83.1)

 Severe

422 (20.7)

1615 (79.3)

Fatiguing or painful posture

<  0.001

 None

386 (5.5)

6575 (94.5)

 Mild

2436 (11.8)

18,191 (88.2)

 Moderate

2077 (21.7)

7499 (78.3)

 Severe

1137 (31.7)

2451 (68.3)

Lifting or moving people

<  0.001

 None

3548 (15.1)

20,004 (84.9)

 Mild

2042 (13.8)

12,727 (86.2)

 Moderate

285 (14.9)

1630 (85.1)

 Severe

161 (31.2)

355 (68.8)

Dragging, pushing, or moving heavy objects

<  0.001

 None

986 (8.8)

10,202 (91.2)

 Mild

3334 (15.5)

18,217 (84.5)

 Moderate

1291 (20.6)

4982 (79.4)

 Severe

425 (24.4)

1315 (75.6)

Standing posture

<  0.001

 None

577 (9.2)

5665 (90.8)

 Mild

2108 (12.9)

14,202 (87.1)

 Moderate

2006 (17.1)

9694 (82.9)

 Severe

1345 (20.7)

5155 (79.3)

Repetitive hand or arm movements

<  0.001

 None

448 (8.0)

5148 (92.0)

 Mild

1562 (11.4)

12,187 (88.6)

 Moderate

2061 (17.0)

10,066 (83.0)

 Severe

1965 (21.2)

7315 (78.8)