Spatiotemporal Gait Parameter Changes Due to Exposure to Vertical Whole-Body Vibration

Background Many people are exposed to vertical whole-body vibration (vWBV) on a daily basis during work, recreation, and transportation with detrimental effects on physical and mental health. Studies have shown that lateral vibration at low frequencies (<3 Hz) can result in changes to spatiotemporal gait parameters. There are few studies which explore spatiotemporal gait changes due to vertical vibration exposure at higher frequencies (> 3 Hz). Thus, this study seeks to assess the effect of vWBV on spatiotemporal gait parameters at a greater range of frequencies. Methods Nine male subjects (29 ± 7 years, 1.78 ± 0.07 m, 77.8 ± 9.9 kg; mean ± SD) during Treadmill Walking and seven male subjects (23 ± 4 years, 1.79 ± 0.05 m, 73.9 ± 9.7 kg) during In-Place Walking were tested in this observational case series study while exposed to six randomly ordered vertical vibration frequencies. Load cells measured ground reaction forces during In-Place Walking and sensorized insoles acquired under-foot pressure during Treadmill Walking. Using a two-tailed, paired t-test, effects were assessed for Stride Frequency (SF) in both scenarios and for Center of Pressure velocity (CoPv) and Stride Length (SL) during Treadmill Walking. Results No significant differences were found between vibration exposure and SF during In-Place Walking. Mean SF during In-Place Walking increased between 9.2 - 17.2% when exposed to vWBV without a marked trend. During Treadmill Walking, vWBV exposure was correlated with a decrease in SF, increase in SL, and increase in both Mean and Max CoPv with a significant increase (p-value <0.0083) in Max CoPv at frequencies of 8 Hz and higher. Significance Study results demonstrated that vWBV influences spatiotemporal gait parameters at frequencies greater than previously studied. It is expected that these effects may also result in a higher physiological and cognitive fatigue while moving in a vibrating environment.