Analysis by measurement of physical stresses upon emergency service personnel during the transport of patients on staircases

Status:

completed 11/2018

Aims:

In the course of their duties, ambulance service personnel must frequently transport patients up and down staircases. In the process, they must handle high loads and adopt unfavourable body postures owing to the limited width of the staircases. In addition, they are required increasingly frequently to transport heavy patients.

As a function of the available numbers of ambulance service personnel and the transport equipment employed, high stresses may be placed during these tasks upon the musculoskeletal system and in particular upon the back.

Alternative equipment supplementing the conventional transport equipment is now available for relieving the stress upon the emergency responders. For a number of reasons however, its use is not yet widespread.

In a preceding pilot study, a measurement setup for recording the physical stress arising during the transport of persons on staircases was constructed and trialled. The pilot study yielded initial indications that alternative items of equipment had a stress-reducing effect, and identified scope for optimization of one item of equipment.

This measurement setup was now used in the main study for the performance of further laboratory measurements, in order for the cohort of test persons to be increased to a statistically meaningful size by means of a power analysis based upon the pilot study. The increased number of test subjects then enables the results and trends obtained in the pilot study to be validated. This in turn enables a scientific basis to be produced for the formulation of prevention recommendations for the field.

Activities/Methods:

The body of international literature already gathered concerning the transport of patients on staircases was first updated. Based upon the measurement setup used in the pilot study, laboratory studies were performed with two conventional items of equipment (an escape chair and an emergency carrying sheet) and two alternative items of equipment (a tracked stair chair and an evacuation slide sheet). For the purposes of the tests, pairs of test persons transported a dummy on a staircase, using the four different items of equipment in turn. Altogether, 30 ambulance service employees acted as test subjects in the pilot and main studies.

Multiple measurement systems employed in parallel (three CUELA Inertial and two force measurement handles) were used for measurement of the body posture/movement and the action forces on the two-person teams. The subjectively perceived exertion was recorded by means of a questionnaire (modified Borg scale). Hand action forces, joint angles, joint moments, compressive forces upon the intervertebral discs of the lumbar spine and the subjectively perceived stress were recorded and analysed statistically as the output parameters.

Results:

The study shows that the physical stress upon the ambulance service personnel during the transport of patients can be reduced by the use of the alternative equipment. For example, the mid-median of the hand action force lies above 400 N when the conventional emergency carrying sheet and escape chair are used, and is thus substantially higher than that for the evacuation slide sheet (165 N) or the tracked stair chair (81 N). The subjectively perceived stress also lies within the range of "medium to strong" exertion when the conventional equipment is used, but in the range of "none to medium" exertion when the alternatives are used.

Besides the selection of the equipment type, the findings enabled organizational recommendations to be made, and also recommendations for use of the equipment in the interests of prevention.

At the end of the study, a specialist conference was held at the IFA for various parties involved in the ambulance services (German Social Accident Insurance Institutions, ambulance services, fire services, professional associations, trade unions, research institutes), at which they were able to pool their experience. This assured transfer to practical application by the decision-makers, purchasers, users, and also developers and manufacturers of the equipment.

The study was documented in the form of an IFA Report and presented at a conference at the IFA and in a number of lectures in Germany.

Publication and presentation:

International congress contribution: PREMUS Conference in Bologna am 02.09.- 05.09.2019, Titel: Physical load of rescue workers during patient transport in stairwells

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