In a comparative ergonomic study, three combinations of stretchers with incorporated transporters of brand-name manufacturers – so-called “ambulance cots” or “roll-in systems” – were tested with respect to their ergonomic quality. Twelve male test subjects (Ss) from the invalid transportation sector subjectively assessed the design elements of the stretchers as well as the gurneys via a questionnaire which had been developed specifically for that purpose. Additionally, the Ss were asked to express potential physical complaints resulting from the carrying activity. To that end, the Ss – under controlled conditions – had to carry out 4 different test tasks: carrying in a staircase at two different speeds, attaching of the stretcher onto the transporter as well as loading and unloading of the ambulance cot into and out of the ambulance. For each task, a 78-kg patient dummy was on the stretcher. Thus, differences in strain across the different test objects became visible or could be subjectively experienced. The presentation of results reflects the advantages and disadvantages of the different models' specified design characteristics and possibly permits suggestions for design improvements.

The very detailed subjective assessment of “roll-in systems” and the Ss' subjective evaluation of them via approximately 50 items offer a differentiated view of the work situation. They suggest several concrete changes in order to improve the design. In particular, changes in the design of the different stretchers were recommended in order to reduce the extraordinarily high strain on the paramedics which was also measured via peripheral-physiological methods. It became clear that one system which is widely used in several countries has marked weaknesses. The biggest disadvantage is the unfavorable grip during height adjustments. Furthermore, it is not possible to utilize the so-called “switching technique” in order to relieve the back with the complete ambulance cot. However, even with the other two models, which are similar to each other in terms of the operating elements and their handling, promising approaches to improve these products do exist with respect to the stretchers' weight, their shape and positioning of handles, and the positioning of the release mechanism to adjust the length of the handle.

The results of this study reveal the necessity for industry to manufacture user-friendly and safe ambulance cots for the market. Paramedics cannot risk to use an equipment which is inadequate or works deficiently. Furthermore, an ergonomic design of the product additionally increases the safety and user-friendliness of the system during a rescue operation. Thanks to the ergonomic design, less effort is needed during the transport of the patient, which at the same time means lower physical strain for the paramedics' back and their hand-arm-shoulder system.