Systematic review of quantitative imaging biomarkers for neck and shoulder musculoskeletal disorders
INTRODUCTION Neck pain in the Canadian Forces (CF) helicopter community related to night vision goggles (NVG) use is of growing concern. This study compares symptom reports and physiological responses and provides comparison between pilots and flight engineers (FE). METHODS Aircrew (22 pilots, 18 FE) detailed their neck pain symptoms, flight history, and fitness results. Subjects participated in isometric testing of flexion, extension, and right and left lateral flexion of the cervical spine that included maximal voluntary contraction (MVC) force and 70% MVC endurance trials. Cervical muscles were monitored with electromyography (EMG) and near-infrared spectroscopy (NIRS) and ratings of perceived exertion (RPE) were collected. RESULTS Of the aircrew, 53% reported neck pain. No significant differences were observed between pilots and FE with respect to frequency of reporting pain. MVC results were found to differ when extension was compared to flexion and when left flexion was compared to right flexion. Time-to-fatigue (TTF) results were obtained and no significant differences were found between groups. EMG assessment of normalized median frequency indicated fatigue onset while NIRS results changed from baseline for most variables during the time-to-fatigue trials. DISCUSSION Neck pain in Canadian Forces helicopter crewmembers continues to be an occupational concern. No significant differences between FE and pilot results were found, suggesting that the cause of the pain is likely something common to both aircrew during flight.