Work above shoulder level and degenerative alterations of the rotator cuff tendons: A magnetic resonance imaging study

Abstract

Objective. To determine whether work performed with the arms in a highly elevated position is associated with alterations in the rotator cuff tendons as assessed by magnetic resonance imaging (MRI).Methods. A cross-sectional study was performed in a historical cohort of male machinists, car mechanics, and house painters. The participants were righthanded, ages 40-50 years, and had been employed in their trades for not less than 10 years. Seventy-one percent of invited subjects participated (136 of 192). Lifetime upper arm elevation was assessed by direct measurements combined with individual work histories obtained by questionnaire and from registry data. Supraspinatus tendinopathy was evidenced by MRI signal intensity changes and morphologic alterations. Infraspinatus and subscapularis tendinopathy were also assessed. Additional outcomes were acromioclavicular joint degeneration and humeral head cysts. The MRI findings were evaluated by radiologists who were blinded to exposure status and symptoms.Results. An exposure-response relationship was found between lifetime upper arm elevation and supraspinatus tendinopathy, with an age-adjusted odds ratio of 1.27 (95% confidence interval 1.02-1.60) for a 5-month increase in the total number of fulltime working months spent with the arm elevated >90 o .Conclusion. Work with the arms in a highly elevated position is associated with MRI-diagnosed alterations in the supraspinatus tendon. By demonstrating the first part of a possible biologic pathway, the study corroborates the work-relatedness of rotator cuff disorders.

Risk factors for incidence of rotator cuff syndrome in a large working population

“…The same result was reported for the prevalent cases at baseline (7), in agreement with other cross-sectional studies (3,10). Svenden et al (11) reported that working with the arms in a highly elevated position was associated with MRI-diagnosed alterations in the supraspinatus tendon. Moreover, in our study the strength of this association increased when working with arms above the shoulder was combined with high perceived physical exertion.…”

Risk factors for upper‐extremity musculoskeletal disorders in the working population

“…A sustained or repetitive working posture with arms at or above shoulder level was clearly associated with upper-extremity musculoskeletal disorders. This posture may be related to rotator cuff syndrome, and several pathophysiologic mechanisms may be involved (e.g., compression and ischemia of the tendons due to impingement and increased intramuscular pressure) (1,18). Sustained or repetitive bending of the wrist and, to a lesser extent, pressing with the base of the palm increased the risk of upper-extremity musculoskeletal disorders, in accordance with epidemiologic (1,2,8,32) and biomechanic (1,2,32) literature on carpal tunnel syndrome.…”

Personal, biomechanical, and psychosocial risk factors for rotator cuff syndrome in a working population

“…Work-related biomechanical exposure has been associated with higher risk of RCS, especially repeated and sustained shoulder abduction and flexion (2,11,(14)(15)(16)(17), heavy lifting, forceful manual exertion (2,11,(14)(15)(16)(17)(18), repetitive movements of the hands (2,11,14,15), and cumulative exposure to these factors (2,9,11,18). An association between RCS and the use of vibrating hand tools and trunk flexion has less often been reported (11,18).…”