Comparison of Patient Comfort and Acceleration Exposure During Lifting and Loading Operations Using Manual and Powered Stretchers.

Objectives: To compare the effects of powered and manual stretchers on participants' perceived comfort and measured acceleration during lifting and loading operations.

Methods: This non-randomized, laboratory-based crossover study involved forty-one participants (thirty-one firefighters and ten third-year paramedic students) who served as simulated patients experiencing lifting, lowering, loading, and unloading maneuvers using manual and powered stretchers. Four stretcher types were evaluated: one powered stretcher (Power-PRO^™ XT) and three manual stretchers (Matsunaga GT, Exchange 4070, Scad Mate), with each group using the manual stretcher they routinely operated. Linear acceleration data were collected using a nine-axis inertial measurement unit placed at the participants' anterior waist. Root mean square (RMS) and peak accelerations along the X-, Y-, and Z-axes were calculated. Participants completed a twenty-three-item comfort questionnaire based on the Semantic Differential method. Due to non-normal data distribution, nonparametric statistical tests were employed for analysis.

Results: The lifting/lowering and loading/unloading movements showed that the powered stretcher significantly reduced the RMS values, maximum accelerations, and minimum accelerations in the vertical axis (Z-axis) compared to manual stretchers. Specifically, the powered stretcher demonstrated lower RMS acceleration (0.29 m/s² vs. 0.73 m/s², p < 0.001), maximum acceleration (1.60 m/s² vs. 2.90 m/s², p < 0.001), and minimum acceleration (-1.48 m/s² vs. -3.30 m/s², p < 0.001) in the vertical direction compared to other manual stretchers. Similar results were observed in the comparison of participant loading/unloading movements. However, no significant differences were observed between the powered and Exchange stretchers in X-axis minimum acceleration, Y-axis maximum and minimum accelerations, or Z-axis maximum acceleration. Similarly, Y-axis minimum accelerations did not significantly differ between the powered stretcher and Matsunaga GT or Scad Mate stretchers. After loading and unloading movements, the questionnaire results showed that the powered stretcher was rated significantly higher on comfort-related items including "comfortable," "secure," "like," "smooth," and "relaxing."

Conclusions: In a controlled, laboratory-based setting, simulated use of manual and powered stretchers showed that powered stretchers significantly minimize patient discomfort and vibrations. This study underscores the potential for enhancing patient safety and quality of care. In conclusion, the powered stretcher is a promising tool for improving the quality and safety of patient transportation in prehospital settings.