Adjusted odds ratios (OR)* with 95% confidence intervals of surgery for subacromial impingement syndrome in relation to duration of exposure (years) at different repetition intensities; single or combined with other mechanical exposures across 10-year exposure time windows. Single: Adjusted for the other two repetition duration variables, age, sex, region of residence, calendar year at start of follow up, number of follow-up years, and cumulative effects of three other mechanical exposures including hand-arm vibrations. Combined: Adjusted for the other two repetition duration variables, age, sex, region of residence, calendar year at start of follow up, number of follow-up years, cumulative exposures of one or two other mechanical exposures including hand-arm vibrations and the two variables, which counted years of exposure with one specific mechanical exposure occurring without the other.