+Gz Exposure and Cervical Spine Degeneration on MRI Among Fighter Pilots: A 10-Year Follow-Up Study

INTRODUCTION: Fighter pilots are exposed to high +Gz forces, helmet-mounted equipment, and extreme head positions that potentially cause cervical spine degeneration and pain. This study aimed to investigate whether individual +Gz exposure, quantified by Fatigue Index (FI), predicts cervical spine degenerative changes and neck pain over a 10-yr follow-up. METHODS: A total of 56 Finnish Air Force fighter pilots were followed prospectively for 10 yr. +Gz exposure was recorded using flight hours and FI recordings. Cervical MRI was performed at the baseline and during the follow-up and evaluated by two radiologists. Annual health questionnaires were used to assess neck pain symptoms. RESULTS: Pilots in the highest annual FI quartile had a significantly increased risk of flight-related neck pain (risk ratio 2.61) compared to others. In contrast, higher annual flight hours were not associated with flight-related neck pain. Before correction for multiple comparisons, new intervertebral disc herniations and foraminal stenosis at the C3/C4 level were also associated with higher cumulative FI levels. Flight hours were at first associated with only intervertebral disc herniations at C3/C4, but this association also lost significance after correction for multiple comparisons. DISCUSSION: To our knowledge, this is the first study to report harmful effects of +Gz exposure using a metric other than flight hours. Higher cumulative +Gz exposure, measured by FI, was significantly associated with flight-related neck pain. Although we observed a potential association between higher cumulative FI levels and cervical spine degeneration at C3/C4 level, this finding did not remain statistically significant after correction for multiple comparisons. Keskimölö T, Kiviaho A, Karppinen J, Honkanen T, Sovelius R, Murto N, Kerttula L, Nykter M, Leino T. +Gz exposure and cervical spine degeneration on MRI among fighter pilots: a 10-year follow-up study. Aerosp Med Hum Perform. 2026; 97(6):419-428.