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Adam Jay
02-09-2009, 11:30 PM
I am a masters student in biomedical engineering. I am hoping to study the biomechanics of the slip recovery response due to an induced slip during walking. Our gait lab currently does not have a fall arresting system so I am designing an overhead rail and trolley system. The test subject will wear a full body harness and be attached to the trolley by a fall arresting lanyard.

In order to select optimal components I would like to have an idea of how large the loads produced during the arrest of a fall from standing position (specifically due to a backward loss of balance) are. I was wondering if anyone has done any tests to measure these loads, or whether anyone doing research in this area uses an in-line force transducer in their fall arresting lanyard and knows what the maximum typical fall arresting loads are (in the case of a fall).

Based on my research and some calculations I plan to use a design load of 2000 lb for my anchorage connector (I-beam rail). I am interested in what others have used for design loads. In fall arrest applications generally an anchorage capable of supporting 5000 lb is required and fall arrest loads are limited to less than 1800 lb by some sort of deceleration device. However, in most situations the free-fall distance is much larger than in the case of a fall from standing. Therefore, I expect that the design load could be much smaller provided a suitable deceleration device is used.

So my two questions are: 1) do you have or know of any experimental data on the fall arresting loads developed during the arrest of a fall from standing position, and 2) in the design of your fall arrest anchorage for fall arrest from standing position, if you have used an anchorage with a design load of less than 5000 lbs what load did you use and how did you justify it?

Thank you for your time and advice.Adam Jay Institute of Biomedical EngineeringUniversity of New Brunswick25 Dineen DrivePO BOX 4400Fredericton, NB, E3B 5A3CANADA Tel: (506) 453-4966Fax: (506) 453-4827