Table 2 Basic characteristics of study population and distribution of shoulder symptoms
Variables | Shoulder symptoms | No shoulder symptoms | |||
|---|---|---|---|---|---|
n = 284 | n = 647 | p-value | |||
Age (years) | 0.04 | ||||
 ≦40 | 174 | (61.3%) | 442 | (68.3%) | |
  > 40 | 110 | (38.7%) | 205 | (31.7%) | |
Sex | 0.03 | ||||
 Female | 96 | (33.8%) | 174 | (26.9%) | |
 Male | 188 | (66.2%) | 473 | (73.1%) | |
Body height (cm) | 167.0 | (8.8) | 167.4 | (8.3) | 0.39 |
Body weight (Kg) | 68.8 | (14.8) | 70.0 | (13.6) | 0.06 |
Body mass index (kg/m2) | 24.5 | (4.1) | 24.9 | (4.1) | 0.13 |
Experience at the job (years) | 5.2 | (5.1) | 5.3 | (5.6) | 0.69 |
Psychological stressa | 0.14 | ||||
 Never | 24 | (8.5%) | 72 | (11.1%) | |
 Some periods | 120 | (42.3%) | 274 | (42.4%) | |
 Several periods | 112 | (39.4%) | 262 | (40.5%) | |
 Permanent | 28 | (9.9%) | 39 | (6.0%) | |
Work-related physical fatiguea | 0.06 | ||||
 Never or almost never | 15 | (5.3%) | 52 | (8.0%) | |
 Seldom | 101 | (35.6%) | 272 | (42.0) | |
 Quite often | 143 | (50.4%) | 279 | (43.1%) | |
 Yes, nearly always | 25 | (8.8%) | 44 | (6.8%) | |