The Graspable Handrail
Jake Pauls
This summary pertains mainly to stairway handrail use by adults. It expands upon an article published in 1991 (Reference 1), particularly that article's list of several handrail functions, the most important of which is "graspable support... to maintain or recover postural support during walking—especially during a misstep, such as on a stair." For children's use of stairs and handrails, see the postscript to this summary.
Stairway handrails that will function reasonably well for usability and safety must be
- Predictably and easily reached by users of varying stature while stepping onto, on and from the stair flight.
- Readily and reliably grasped with hands of varying size, dexterity and strength.
- Sufficiently stable structurally to provide reliable guidance and postural support in normal use and when a misstep (precursor to a fall) occurs.
To provide these functions the handrail(s) must be geometrically positioned
- At a biomechanically effective and consistent height (for example, no lower than the adult users' elbow height or about 940 to 1000 mm, 37 to 39 inches, above stair step nosings and landing floors).
- Within lateral reach distance so that everyone on a stair is within lateral reach of at least one handrail (for example, within 750 mm, 30 inches, laterally of any part of the stair width expected to be used by people).
- With continuity so that, once contacted by a user's hand before taking any step onto the stair flight until the user's leading foot contacts the landing floor below the stair flight, the handrail can be comfortably grasped—both loosely and tightly—without any drastic change in the arm-hand relationship.
- With sufficient clearance, between the handrail and supporting structure (bracket and wall for example) for fingers to effectively approach the handrail in a grab response and either curl underneath the handrail with only comfortable, noninjurious bracket/picket contact or hang vertically down the side of the handrail without contacting the lateral portion of the bracket.
Furthermore, for effectiveness—especially in helping a person to arrest (mitigate) a misstep and potential loss of balance or footing—the handrail must have the following:
- A shape to which a person's hand can readily conform without undue pressure from small-radius corners (preferably no smaller than 6 mm, 0.25-inch radius); this is best achieved with a round handrail.
- A size allowing a power grip, with all fingers and thumb able to curl around the handrail regardless of the direction of the hand's approach to the handrail. (This means having a total perimeter dimension—measured by wrapping a measuring tape completely around the railing section—of between about 100 and 160 mm, 4 to 6.25 inches.)
- A surface finish that allows comfortable sliding of the hand when the handrail is loosely held and adequate friction to limit slippage when tightly grasped.
- For outdoor conditions, thermal characteristics that will not be uncomfortable or injurious in summer heat or winter cold.
Handrails complying with the requirements of the 2003 edition of the ICC/ANSI A117.1 standard will generally come very close to meeting all of these functional criteria (aside from those dealing with surface finish and thermal characteristics for which the standard has no requirements). Handrails complying with the ICC International Residential Code (IRC) will not necessarily comply as this code permits many dysfunctional features for dwelling unit handrails, especially those serving stairways. For example, in the 2003 edition, provision of handrails is not required for all stairs (under the scoping in section R311.5.6); full continuity is not required (under section R311.5.6.2); and graspability is violated with the so-called "Type-II" handrails (under "grip size" requirements of section R311.5.6.2). Figures 1a and 1b illustrate just how bad a stairway can be if it mostly complies with IRC's compromised stairway rules and incorporates several dysfunctional features—even though it is the "Universal Design Demonstration" house (in Prince William County, Virginia) widely discussed during late 2006 and early 2007.
Figure 1 (a) the overall view and a top-of-flight detail of a traditionally detailed Type II handrail, with (b) one aspect of its dysfunctional geometry illustrated by internationally-known Universal Design authority, Satoshi Kose.
IRC requirements for the Type II handrail have been relatively intensively debated recently as the Stairway Manufacturers Association (SMA) has been attempting to have Type II handrails accepted for non-dwelling contexts in the ICC International Building Code and in the forthcoming edition of the ICC/ANSI A117.1 standard for all handrail contexts. While the debates have addressed several research issues, the grip performance differences between the so-called Type I handrails (which comply with A117.1-2003 and mostly meet the bulleted functional criteria listed above) and the Type II handrails (which do not comply with A117.1-2003 and mostly do not meet the bulleted functional criteria listed above) can be summed up as follows:
- Type I handrails facilitate a power grip with thumb and other fingers able to curl underneath the handrail while the Type II handrails only facilitate what can be functionally described as a pinch grip with thumb and other fingers separated by a minimum of about 37 mm, 1.5 inches, of handrail material (typically wood for such handrails). See Figure 2.
- Type I handrails work relatively well for a wide range of hand sizes, allowing full conformance or contact with hand surface with the hand approaching the handrail from any direction, while Type II handrails are very dependent on hand size and approach direction. See Figure 2.
Figure 2
Notably, in Figure 2, the upper portions of the two shapes are relatively similar so that if viewed from directly overhead, they appear alike. Other shapes that comply with requirements for Type I handrails are shown cross-hatched in Figure 3, which compares the sizes and shapes of many railing sections (not including R) that were tested in 1985 in a study of adults in Toronto, Canada, by Dr. Brian Maki as part of the most extensive research to date—in terms of variety of shapes and sizes—of handrail graspability plus stairway use and safety biomechanics (Reference 2). Note section D, the 2-inch diameter round, was questionable; it is too large for some adults and for most children.
Figure 3
Rail shapes, A to Q, tested for quality of grip by Brian Maki for National Research Council of Canada. Cross-hatched sections function relatively well. Crossed out sections are not recommended.
To help improve development of codes and standards, a critical review (based on European plus North American research) was done for the Building Research Establishment in the UK in 1994 by Feeney and Webber (Reference 3). This science-based review concluded, "guidance that can be provided with confidence is...
- The handrail height should be between 935 and 1000 mm above the pitchline for adults.
- The shape should be circular and of 32 to 50 mm diameter, or oval with a thickness of 18 to 37 mm horizontally and 32 to 50 mm vertically.
- The handrail should be varnished hardwood, enamel paint on metal or vinyl, or Doverite-covered steel."
The largest recommended section with the oval shape was tested in 1985 by Maki (Section P in Figure 3). The oval is an example of a non-circular shape that performed well in testing of both functionality and user preference. Biomechanically, it is best oriented vertically so that bending of the user's wrist is minimized.
Figure 4 depicts such an oval handrail in use with a relatively large male hand. The bracket and wall mounting plate illustrate some other features of good handrail geometry as shown in the seventh bulleted item in the list of functional criteria with which this article opens. In the view of this long-term student of stairs, handrails and the associated ergonomics, Figure 4 represents the best, most comfortable and most usable handrail shape that is not circular. Many professionals in the building industry would agree with this opinion if they fully understood the ergonomics behind it or, failing that, if they merely noted that no handle for a power or manual tool used in the building industry has a shape and size anything like the Type II handrail—which would quickly lose market share once people realized just how dysfunctional it is for the human hand, particularly the hand of someone challenged by stairway use and safety.
Figure 4
Lateral clearance between handrail and wall and vertical clearance underneath the handrail facilitate a grab response, as well as relaxed use of the handrail with fingers extending downward, ready to curl under the handrail and achieve a power grip as illustrated.
Postscript
Regarding research behind current understanding of handrail usability and safety, a major development was the research completed in 1996 by Maki and colleagues on the grab response for a handrail (specifically one with a round section of 51 mm, 2-in diameter). First proposed in 1987, in conjunction with Maki's work for the National Research Council of Canada, the testing eventually received funding from the SMA which finally recognized the quality of Maki's research. It was published in a peer-reviewed journal in 1998 (Reference 4). (A review of all the handrail work by Maki and colleagues was published in 2006, Reference 5.) Much of the current debate on other research funded by SMA—specifically the work it claims to show the comparable performance of certain Type II and certain Type I handrails—would be much more focused and productive if the other SMA-funded research was also published in detail in a peer-reviewed journal recognized for its stature in safety and ergonomics. This other research by Dusenberry and colleagues entailed a very unrealistic testing protocol with subjects' arms stretched out horizontally on a table with (ultimately) a hook grip on test railing sections. To date these other studies have been very inadequately reported formally and then only in relatively obscure conference proceedings that have relatively little impact in the safety and ergonomics field (References 6 and 7). Finally, regarding children's use of stairs and handrails, see Reference 8.
Jake Pauls, CPE (Certified Professional Ergonomist), has 41 years of experience in international research, consulting, falls investigations and work on numerous codes and standards (with several committee appointments in the USA, mostly representing the American Public Health Association) in North America and overseas. For full information—including free access to over 80 papers and presentations on egress performance, falls and stairway design plus regulation internationally—see http://web.mac.com/bldguse. (In the interests of full disclosure, the studies by Brian Maki and colleagues, between 1982 and 1987, referred to in this summary were performed with funding from Jake Pauls' biomedical engineering research program, focused on fall-related injury prevention, at the National Research Council of Canada.)
References
- Pauls, J. Are functional handrails within our grasp? Building Standards, January/February 1991, 6-12; The Building Official and Code Administrator, March/April 1991, 25-32.
- Maki, B.E. Influence of handrail shape, size and surface texture on the ability of young and elderly users to generate stabilizing forces and moments. Report for Biomedical Engineering Research Program, DEE, National Research Council of Canada, Ottawa, 1985.
- Feeney, R.J. and Webber, G.M.B. Safety aspects of handrail design: A review. Building Research Establishment Report, BR260, Garston, Watford, U.K., 1994.
- Maki, B., Perry, S.D. and McIlroy, W.E. Efficacy of handrails in preventing stairway falls: A new experimental approach. Safety Science, Vol. 28, No. 3, 1998, 189-206.
- Maki, B.E., Perry, S.D. Scovil, C.Y. Mihailidis, A. and Fernie, G.R. Getting a grip on stairs: research to optimize effectiveness of handrails. Proceedings of IEA2006, 16th World Congress on Ergonomics, Maastricht, 2006.
- Dusenberry, D.O. and Simpson, H. (1996). Handrail graspability. Proceedings of 11th Conference, Engineering Mechanics Division, American Society of Civil Engineers, May 19-22, 1996, 466-469.
- Dusenberry, D.O., Simpson, H., DelloRusso, S.J., and Rao, R.S. Evaluation of graspability of handrails during falls on stairs, Proceedings of the 13th Conference of Engineering Mechanics, Baltimore, MD, June, 1999.
- Pauls, J. Stairways for Children. In Ergonomics for Children: Designing products and places for toddlers to teens, Lueder, R and Rice, V. (Eds.), CRC Press, Taylor and Francis, Boca Raton, FL, 2007, 543-571.


