David Cooper's Rebuttal to "The Graspable Handrail"

I will not address or contest much of Mr. Pauls' initial comment except to say he has hypothesized or suggested opinion as fact based on early studies of very limited adult populations prior to SMA funded research. You will find nothing within this body of work that defines what it is about a handrail shape that makes it graspable.

It was in full recognition of the many limitations, qualifications, and recommendations for further studies stated within this early valued work by Dr Brian Maki that we have also cited these studies. In fact this work precipitated SMA funded research and testing to explore the recommendations of Dr. Maki for further testing. Through the third party Simpson Gumpertz & Heger, a dynamic testing protocol was developed and performed in cooperation with Dr. Maki. This testing and additional testing resulted in the Type II standard.

On the other hand Mr. Pauls has successfully marketed his opinion to the code and standard community. He has done so with little more than circular conjecture such as the reference to Pauls' 1991 paper based on the same preliminary limited studies and has failed to sponsor any further testing. Opinion is just that, the basis for such should always be questioned and updated.

Mr. Pauls' graphical depictions, cartoon like in nature, support his opinion. The caption of Pauls figure 3 states that only a portion of the profiles shown were tested. In this rendition, profile "Q" is X'd out, as "not recommended". Mr. Pauls also excludes this from his list of the profiles tested by Dr. Maki. The once common "ADA" rail shown as "Q" has been deemed inadequate by opinion not scientific evidence. The caption leads one to think that this is Dr. Maki's opinion rather than the author's. This depiction by Pauls' bears much responsibility for this handrail profile being eliminated from the ADA Guidelines. Until I called Mr. Pauls on it this same graphic ploy was used including other profiles now restricted from the IBC, NFPA, and A117.1.

The sketched depiction of grips in Pauls figure 2 is spurious or desperate at best when compared to the grips actually used on handrails when using stairs and ramps. Such representations do not prove anything to those who can form their own opinion by simply forming a grip while using a stair or ramp handrail.

In Pauls figure 4; note the non-conforming bone structure of the hand creates an evident gap between the hand and the top of the rail. It also clearly illustrates the interference of fingers and thumb if you look carefully behind the disguising arced line. Interference with forming a stabilizing grip caused by supporting brackets and balusters can also be easily identified. Note that these issues would be compounded with the smaller round rails now allowed.

Finally Mr. Pauls comment that Type II rails are hand size specific is not correct. The supporting SMA funded testing included hand sizes across a broad population.

Contrary to Mr. Pauls' approach the SMA has put its energy into funding testing to expand the body of knowledge through science rather than conjecture or opinion based on preliminary, limited studies. SMA funded testing has expelled many common traditional profiles from use but defined a standard for certain handrail shapes with graspable recesses never tested before. This scientific approach, void of opinion has elevated the understanding of graspability. It has further proven that Type II profiles are equivalent to those accepted in the A117.1 standard. This science has been reviewed and accepted for publication in the well-known and highly credible peer review journal "Applied Ergonomics". No manipulation of words or pictures, no smoke or mirrors just science. Look at the A117 presentation cited in my article. The facts are clear and now substantiated by peer review. I would ask Mr. Pauls to consider updating his opinion with the new facts and will look forward to his admonition of more than just his partiality to testing he attempts to claim (in his first paragraph) and supposedly paid for.