A biomechanical and subjective comparison of two powered ambulance cots

Abstract

This study investigated biomechanical effects of different leg folding/unfolding mechanisms used for loading/unloading two powered cots (Cots A and B) into and from a simulated ambulance. Sixteen experienced emergency medical service (EMS) workers loaded and unloaded cots with weights of 45, 68 and 91 kg placed on the cots to simulate patients. Peak back and shoulder/arm muscle activity was reduced 52–87% when using Cot A in comparison to Cot B. Peak ground reaction force (PGRF) was reduced by 74% with Cot A. Adding weight resulted in increased muscle activity and PGRF when using Cot B, but had little effect when using Cot A. Task time was longer with Cot A, though was not perceived unfavourably by participants. This study confirmed that it is possible to substantially reduce physical stress imposed on EMS workers when loading and unloading a cot to and from an ambulance through improvements in cot design.

Abstract

Practitioner Summary: This study compared two powered ambulance cots, one that lifts/lowers the front and rear wheels independently and one that lifts/lowers the four wheels simultaneously during ambulance loading and unloading. Measured muscle activity, ground reaction forces and operator perceptions support using cot designs that lift/lower the front and rear wheels independently.

Keywords:

• ambulance cots
• musculoskeletal injury
• EMS
• paramedic
• occupational injury
• engineering control
• patient handling

Acknowledgements

The authors wish to thank Ferno-Washington, Inc. for their support of this study, including providing access to ambulance cots and the simulated ambulance bed used in this study.

The authors also wish to acknowledge contributions to the pilot work and data collection phases of this study from Tom Stoughton, Xiaojing Wu, Benjamin M. Collins, Adam Kelly, Kyle Hermiller, Brittani Brown, Kailyn Cage, Nicholas Schmidt and Christina Lee.

Disclosure statement

None of the authors have any financial interest or benefit to declare in any regard in relation to the study described in this manuscript. Each author is obliged by our institution to declare any actual or apparent conflicts of interest, annually, as part of the university's protection of human participant process.

Notes

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^4. Email: [email protected].

^5. Email: [email protected].