Work-related upper limb disorders (WMSDs), also known as repetitive strain injuries, affect a large subsection of the US population. These disorders are a significant source of injury, morbidity, loss of work, and pain. We have developed a rat model of upper extremity repetitive work at high forces, and observed exposure-dependent increased inflammatory responses in all tissues involved in performing the task. A 2- to 8-week regimen of oral ibuprofen provided to rats while they continued to perform a high-repetition high-force task ameliorated these inflammatory responses as well as several motor declines. Ibuprofen treatment also attenuated task-induced tissue fibrosis, cartilage degeneration, and bone osteopenia, indicating their link to inflammatory processes. However, ibuprofen did not significantly attenuate persistent nocifensive pain behaviors (reflexive grip strength results are presented) likely because of persistent increases in inflammatory cytokines in the spinal cord, suggestive of central sensitization. Since long-term ibuprofen use can induce a number of negative side effects, such as gastritis, multi-pronged approaches should be considered with anti-inflammatory drugs included for only short time periods.
Part of the book: Occupational Health