Consumer opinion of stair descent devices used during emergency evacuation from high-rise buildings.

The use of stair descent devices is an important part of a comprehensive emergency evacuation plan. To date, there is little research on consumer opinion of these devices. A pilot study was performed at a local center for independent living, enabling 14 consumers with mobility impairments to state their initial impressions of 14 devices, representing three general designs: carry-type, track-type, and sled-type. Consumers were able to view the devices, ask questions, and view short videos of the devices in use. Afterwards, consumers were given the opportunity to try out one or more of the devices, and provide their opinion after each trial run. Consumers provided feedback on specific design features, how they anticipated they would feel about using each, and whether they considered each device acceptable for use. Trial use enabled more in-depth opinions, and in some cases, a change in opinion on acceptability.

Evaluating the physical demands when using sled-type stair descent devices to evacuate mobility-limited occupants from high-rise buildings.

The physical demands on evacuators were investigated when using different types of sled-type stair descent devices designed for the emergency evacuation of high rise buildings. Twelve firefighters used six sled-type stair descent devices during simulated evacuations. The devices were evaluated under two staircase width conditions (1.12, and 1.32 m). Dependent measures included electromyographic (EMG) data, heart rates, Borg Scale ratings, and descent velocities. All stair descent speeds were below those reported during pedestrian egress trials. With the exception of the inflatable device, the devices operated by two evacuators had higher descent speeds than those operated by a single evacuator. High friction materials under the sleds facilitated control and reduced the muscle demands on stairs but increased physical demands on the landings. Usability assessments found devices with shorter overall lengths had fewer wall contacts on the landing, and handles integrated in the straps were preferred by the evacuators.

Evaluating the physical demands on firefighters using track-type stair descent devices to evacuate mobility-limited occupants from high-rise buildings.

The physical demands on firefighting personnel were investigated when using different types of track-type stair descent devices designed for the emergency evacuation of high rise buildings as a function of staircase width and evacuation urgency. Twelve firefighters used five track-type stair descent devices during simulated urgent and non-urgent evacuations. The devices were evaluated under two staircase width conditions (1.12, and 1.32 m), and three devices were also evaluated under a narrower staircase condition (0.91 m). Dependent measures included electromyographic (EMG) data, spine motion, heart rates, Borg Scale ratings, task durations and descent velocities. Stair descent speeds favored the devices that had shorter fore/aft dimensions when moving through the landing. EMG results indicated that there were tradeoffs due to design features, particularly on the landings where the physical demands tended to be greater. On the landings, devices that could be rolled on four wheels reduced the deltoid and bicep activation levels.

Evaluating the physical demands on firefighters using hand-carried stair descent devices to evacuate mobility-limited occupants from high-rise buildings.

The physical demands on firefighting personnel were investigated when using different types of hand-carried stair descent devices designed for the emergency evacuation of high rise buildings as a function of staircase width and evacuation urgency. Twelve firefighters used three hand-carried stair descent devices during simulated urgent and non-urgent evacuations. The devices were evaluated under three staircase width conditions (0.91, 1.12, and 1.32 m). For comparison, an urgent manual carry was also performed on the 1.12 m wide stairs. Dependent measures included electromyographic (EMG) data, heart rates, Borg Scale ratings, task durations and descent velocities. Results indicated that the stair chair with extended front handles, which allows the front person to descend the stairs facing forward, reduced the time integrated back muscle EMG by half and showed a descent velocity that was 1.8 times faster than the other stair descent devices in the study. There were no differences across staircase widths.