Long-term effects of biomechanical exposure on severe shoulder pain in the Gazel cohort

We aimed to assess whether the risk factors for severe shoulder pain, especially exposure to arm elevation, were still relevant after a 12-year follow-up, even following retirement.

All men participating in the ARPEGE ancillary study of the GAZEL cohort (followed-up since 1989) and who answered the 1994 or 1995 general GAZEL self-administered questionnaire were included. Weight and self-reported exposure (arm elevation >90° with and without carrying loads) over the entire working life were collected at baseline (1994-1995). Shoulder pain and its intensity were recorded in 1994-1995 and again in 2006. Shoulder pain was measured on an intensity or discomfort 6-point scale in 1994-1995 and on an 8-point scale in 2006. Severe shoulder pain was defined as point-rated higher than the mid-points (>3/6 in 1994-1995 and >4/8 in 2006) while moderate pain was lower or equal to these thresholds.

At baseline, 1786 47-51-year-old men were included. In 1994-1995, moderate pain was observed among 8.5% (N=151) of men and severe shoulder pain among 14.6% (N=261). Exposure to arm elevation >90° while carrying loads was significantly associated with severe shoulder pain with >25 years of exposure [adjusted odds ratio (OR (adj)) 4.2, 95% confidence interval (95% CI) 1.7-10.5], taking into account age, sports, smoking habits, history of shoulder trauma, and body mass index. In 2006, when most of the subjects had retired, 1482 men (83.0%) answered the questionnaire, 17.3% of them with severe shoulder pain; the association between exposure to arm elevation >90° while carrying loads and severe shoulder pain was still significant (ORadj 3.3, 95% CI 1.3-8.0), and remained so when subjects with shoulder pain at baseline were excluded.

Among men, the effect of high shoulder exposure (arm elevation >90° while carrying loads) during working life on severe shoulder pain remains even after retirement. Extended surveillance and prevention should be offered to these workers.