Recommendations on Standards for the Design of Medical Diagnostic Equipment for Adults with Disabilities, Advisory Committee Final Report

Examination Tables and Chairs Subcommittee Report (including height position discussions as requested by full committee)
May 28, 2013

Introduction

The Tables & Chairs Subcommittee met six times via conference call. We began our discussion by reiterating that the intent of the proposed standard is to provide for independent access to and use of diagnostic equipment.

First, we discussed in length the definitions/differences between examination tables and chairs to understand the medical equipment we are discussing. Subcommittee members felt that the definitions should be based on how the device is defined by manufacturer as follows:

Manufacturers design examination tables with primary functions of supporting patients in a prone position, side-lying position, or both.

Manufacturers design examination chairs with primary functions of supporting patients in a seated or supine position.

Summary of Recommendations

Transfer Surface Size – M302.2.2 Seated Position

The issue of seat depth was discussed and decided during the full committee meetings as follows: depth of 17 inches minimum. The Subcommittee discussed the width and agreed on a 21 inch minimum width based on anthropometric data and industry human factors experience. In addition, examination chairs that cannot be entered on the foot end, such as dental chairs and podiatry chairs, the subcommittee members agreed that the 17 inch minimum depth and 21 inch minimum width be located on both sides of the chair to allow for a left or right transfer (see examples below).

Transfer Surface Size – M301.2.2 Supine, Prone, or Side-Lying Position

The issues were discussed and decided in the full committee meeting as follows: depth of 17 inches minimum and width of 28 inches minimum.

Podiatry Chair, Side View

Podiatry Chair, Top View

Dental Chair, Side View

Dental Chair, Top View

Height – M301.2.1 & M302.2.1

The subcommittee discussed the increments for adjustability and decided that infinite adjustability is the appropriate standard as both electronic and manual pump chairs have ability to stop at any position.

The discussion for the low end of the minimum range consumed a majority of the Subcommittee’s time. The final recommendation of the subcommittee to the full committee was a recommendation of 19 inches with a "best practice" standard of 17 inches. Upon consideration of the subcommittee’s final recommendation, the full committee was unable to come to a consensus around any specific low height requirement, nor the “best practice” recommendation. Therefore, the report presents each of the arguments in favor of the proposed low height measurements – 19 inches, 18 inches, and 17 inches:

17 Inch Low Height

A portion of the Committee maintained that a height range of 17 inches - 25 inches would accommodate a significant portion of people with disabilities. Data provided to the Committee and expert advice of medical practitioners led many to conclude that a lower height of 17 inches is essential to ensure safe transfers by patients with disabilities and thus, accomplishes accessibility for the greatest number of people.

Studies of Wheeled Mobility Devices and Transferring Abilities

Accessible medical equipment needs to facilitate safe transfers that accommodate the largest possible portion of people with disabilities, including people who use wheeled mobility devices. The safest and most easily accessible transfers are those with no or very little horizontal and vertical distance between the seat of the wheelchair and the transfer surface. Specifically, transferring to a higher surface applies greater exertion of the upper limbs.¹ 

A study of wheeled mobility devices, including manual wheelchairs, power wheelchairs, and scooters examined the seat height of 495 users. The height was measured as the vertical distance from the floor to the lowest point of the seating surface of the mobility device, while the occupant was seated in the device. Thus, the surface of the mobility device was in a compressed state. The study noted that a range of 17 inches -25 inches accommodates the vast majority of wheeled mobility device users, while continuing to exclude 6% of manual wheelchair users whose devices are lower than 17 inches. Increasing the low end to 19” height excludes many users, specifically over 30% of female manual chair users and over 15% of male manual chair users.² 

There is limited information on the ability of people with disabilities to transfer to a height different from the height of their wheeled mobility device. The Impact of Transfer Setup on the Performance of Independent Transfers: Final Report provides an analysis of the effect of height, horizontal gap, placement of armrests, and placement of grab bars on a person’s ability to transfer. The study noted that 86% of wheeled mobility device users could transfer to heights that were 2 inches above and below the height of their wheeled mobility device. However, this study was not representative of the diversity of wheeled mobility device users. Individuals were explicitly excluded from the study if they had significant upper extremity pain or injury that affects the ability to perform transfers, or had an active or recent history of pressure sores. Furthermore, the vast majority of subjects in the study were men.³ Numerous research studies as well as anecdotal reports from people with a variety of mobility disabilities (spinal cord injury, cerebral palsy, polio, traumatic brain injury, etc.) have detailed and reinforced that fact that people who live with disability experience a greater prevalence of and earlier onset of age related conditions such as arthritis, pain contractures, weakness, deconditioning, and shoulder injuries etc.⁴

Data Deficiencies

Advocates on the committee, representing the interests of people with disabilities, strongly stated that a 17” height is essential to accommodate the largest segment of people with disabilities. While general information can be found regarding average height of wheeled mobility devices, and people’s ability to transfer, data is not available regarding the needs of people of short stature and people with mobility disabilities who do not use wheeled mobility devices. The promulgation of standards for accessibility is required to take into account all people with disabilities, not just those who use wheeled mobility devices. In the absence of additional data, being inclusive versus exclusive is the most responsible approach in the development of standards.

Expert Advice of Medical Practitioners

Numerous practitioners commented on the importance of the availability of a lower transfer surface. Nüket J. Curran, PT, Director, Quality & Risk Management at UPMC Centers for Rehab Services, noted the importance of patient safety, staff safety, and ease of use. She stated that a 14 inch high transfer surface on tables and chairs would be ideal to facilitate the safest transfers, noting that 17 inches can be too high for some people. Ms. Lauren Snowdon, PT, DPT, Clinical Manager at the Kessler Institute for Rehabilitation, provided in depth analysis of the transferring abilities of wheeled mobility device users and the ideal height of transfer surfaces. Based on her experience that the general range of customized manual wheelchair height is 15.5 inches- 19.5 inches and that power wheelchairs range from 16.5”- 22” high, she stated that the option of a 17 inch high surface would be preferable to a 19 inch height. A 17 inch height allows for safer, easier transfers of patients whose wheelchair height is at the low end of those ranges. Other practitioners stated that the current height option of 18” was satisfactory and facilitated safe transfer for most patients. However, within this group, there was also a general consensus that a 17 inch height would provide greater accessibility, and enhance the safety of transfers for some patients. Given the importance of safe transfers and height ranges of wheeled mobility devices, a low height of 17 inches is considered by some to be a compromise solution.

The Limits of Utilizing a Cost-Benefit Analysis

Many advocates strongly cautioned against attempting a strict cost/benefit analysis when ample data is unavailable. To our knowledge there are no studies that provide a fully comprehensive analysis of the effects of the height of a transfer surface on people with various disabilities. Additionally, every time a patient with a disability is denied access to health care due to an inability to access equipment, the cost is often far more than traveling to a different health care facility. Delayed diagnosis and treatment translates into higher HEALTH CARE costs due to the need for more extensive and expensive treatment. Furthermore, the cost of the systemic denial of health care to these individuals can be life threatening.

There is additional risk to patients when medical practitioners attempt to manually transfer patients to diagnostic equipment. Risk of injuries due to being dropped, as well as skin shear and shoulder injuries can occur when the transfer surface cannot be adjusted low enough to accommodate a straight transfer for individual wheeled mobility devices of varying heights. The cost of medical practitioner injuries while performing these types of tasks has been widely documented and should also be considered.

While, there are always practical limitations on accommodating every individual, in the case of access to a service as essential as health care, advocates strongly urge the Access Board to develop standards that are not only practical to industry interests, but will guarantee access to the vast majority of people with disabilities.

 

Notes 

^1. The Impact of Transfer Setup on the Performance of Independent Transfers: Final Report. Presentation to US Access Board. Washington, DC. 2011

^2. D’Souza, Clive and Edward Steinfeld, IDeA Center. Analysis of Seat Height for Wheeled Mobility Devices. 2011.

^3. The Impact of Transfer Setup on the Performance of Independent Transfers: Final Report. Presentation to US Access Board. Washington, DC. 2011

^4. Jensen, M.P., Molton, I.R., Groah, S.L., Campbell, M.L., Charlifue, S., Chiodo, A., Forchheimer, M., Krause, J.S., & Tate, D. (2011). Secondary Health Conditions in Individuals Aging with SCI: Terminology, Concepts, and Analytic Approaches. Spinal Cord, 50(5): 373-378.

Groah, S.L., Charlifue, S., Tate, D., Jensen, M.P., Molton, I.R., Forchheimer, M., Krause, J.S., Lammertse, D.P., & Campbell, M. (2012). Spinal Cord Injury and Aging: Challenges and Recommendations for Future Research. American Journal of Physical Medicine & Rehabilitation, 91(1): 80. doi: 10.1097/PHM.0b013e31821f70bc. Available from: http://journals.lww.com/ajpmr/Abstract/2012/01000/Spinal_Cord_Injury_and_Aging__Challenges_and.10.aspx. Accessed December 18, 2012.

Turk M. Secondary conditions and disability. In: Field MJ, Jette AM, Martin L (eds). Workshop on disability in America. A new look. Summary and background papers. Board on Health Sciences Policy, Institute of Medicine of the National Academies, The National Academies Press: Washington DC, 2006, pp. 185–193.

Kemp, B.J., & Mosqueda, L. (Eds.) (2004). Aging with a Disability: What the Clinician Needs to Know. Baltimore, MD: Johns Hopkins University Press.

Kailes, J. (2000). Health, Wellness and Aging with Disability, KAILES - Publications, http://www.jik.com/resource.html, jik@pacbell.net This email address is being protected from spambots. You need JavaScript enabled to view it. .

Kailes, J. (1995). "Midlife Cripdom: Getting Fewer Miles per Gallon?" The Disability Rag 16(4).

Kailes, J. (2001). Aging with Disability - Good News and Bad News. Western U-View. XX: 17.

 

18 Inch Low Height

As our discussions progressed on the low height, whether it should be 17 inches, 18 inches or 19 inches; a compromise position of 18 inches was suggested. Some individuals indicated that they would be willing to compromise, but virtually all of the subcommittee members indicated that the 17 inch low height was the most inclusive and reached a broader range of individuals using wheeled mobility devices.

During a Subcommittee conference call, Dr. Edward Steinfeld, the principal author of the Analysis of Seat Height for Wheeled Mobility Devices, stated 17 inches is the best practice as it accommodates approximately 94% of individuals using wheeled mobility devices according to their research (see above). When asked about the 18 inch as the low height, Dr. Steinfeld stated it could be a reasonable compromise since the group most affected by increasing the height would be manual wheelchair users who could accommodate a 1 inch change in vertical clearance during transfer. He also stated there is limited data on the effect of a level change as the distance (gap) between the wheeled mobility device and the piece of medical equipment increased and cautioned against speculating that height differences between the wheeled mobility device and transfer surface would be acceptable to all users.

Finally, a majority of committee members proposed a range for the low height of 17 to 19 inches rather than establishing an absolute minimum. An example of providing a range is the pool seat lift accessibility standard per ADA and ABA 2004 Guidelines Section 1009.2.4, which clearly establishes that, even with adjustable devices, a range for the highest (or in our case lowest) position is suitable and appropriate. Thus, the standard could be stated as follows: the transfer surface must lower to at least 17 inches to 19 inches and infinitely adjust to at least 25 inches above the finished floor.

19 Inch Low Height

Although the subcommittee’s conversations were complex and far-reaching, the following points summarize the factors that lead to the selection of the 19 inch height recommendation:

• Ensures that such equipment is accessible to, and usable by, individuals with accessibility needs and will allow independent entry to, use of, and exit from the equipment by those individuals

• Carefully balances the costs to hospitals, physicians, and other health care providers of replacing or modifying existing equipment together with manufacturer costs of redesigning equipment

• Provides for the least cost to health care system of any option considered by the subcommittee

• Results in the most rapid rate of adoption of accessible equipment by health care providers and the benefits of that equipment to individuals with accessibility needs, particularly those who use wheeled mobility devices.

The memorandum explains why a requirement for a 19 inch lower adjustable height for tables and chairs is the most appropriate standard for the initial implementation of section 4203 of the Patient Protection and Affordable Care Act.

Current Situation: the Vast Majority of Examination and Procedure Tables are 32 Inches High

In the United States, approximately 82 percent⁵ of physicians, hospitals and other health care providers use examination and procedures tables with a 32-inch fixed height, as shown in Figure 1. Industry commonly refers to these tables as "box tables.” These tables provide an often-insurmountable barrier to health care for people with accessibility needs. Since 2001, the number of adjustable-height tables has steadily increased, but continue to represent a minority of examination tables in the United States.

Figure 1: Percentage of fixed height versus adjustable height medical tables

One of the primary objectives of the U.S. Access Board’s requirements should be to accelerate the growing trend of heath care providers to purchase adjustable height tables, which will reduce the number of fixed, 32 inch high inaccessible tables.

Figure 2: Illustration of the height difference between a fixed height and adjustable height medical table

Implications of a 19 Inch Minimum Standard for the Highest Point in the Lowest Adjustable Position

This memorandum presents the factors that support a minimum standard of 19 inches as the highest point on the transfer surface in a table or chair’s lowest adjustable position. However, shorthand references to 19 inches as the minimum standard as used in this memorandum should not be equated with a 19-inch transfer surface height, for two major reasons. First, as depicted in Figure 3, adjustable tables currently on the market generally feature contoured bolsters that provide greater security once an individual is seated or lying on the table or chair. A 19-inch standard means that any bolsters fit within the highest point standard, thereby making the front edge of the table/chair lower than the bolsters (by about ¾” based on currently marketed bolsters, or about 18 inches compressed at the transfer surface).

Second, as a minimum standard, establishing a 19-inch highest point standard does not mean that all newly manufactured tables and chairs will necessarily be fixed at a 19-inch height. Unlike fixed transfer surfaces such as toilets or non-adjustable tables, there is no reason to standardize at a single height based on broadest usability. In a marketplace of adjustable tables and chairs, increased range of adjustability will be advantageous to patients and caregivers alike. It is not unreasonable to expect that table and chair manufacturers will seek to compete by offering products with greater degrees of adjustability.

Figure 3. Illustration of measurement height at bolsters relative to lower transfer surface

Alignment of 19 Inch Recommendation with Access Board Proposed Rulemaking

The subcommittee’s recommendation of a lower adjustable height of 19 inches maximum is consistent with the U.S. Access Board’s proposed rule and supported by public comments. In its proposed rule, the Access Board proposed that the “height of the transfer surface during patient transfer shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum measured from the floor to the top of the transfer surface” for both examination tables and chairs.⁶ The Access Board based its proposal, “on provisions in the 2004 ADA and ABA Accessibility Guidelines for architectural features that involve transfers (e.g., toilet seats, shower seats, dressing benches).”⁷ In addition, the Access Board recommended, “Where patient support surfaces are contoured or upholstered for patient comfort or to support patient positioning during diagnostic procedures, the height of the transfer surface measured from the floor may vary across the transfer surface. The highest and lowest points of the transfer surface on such equipment would have to be within the specified dimensions.”⁸ The Access Board proposed that the measurement should be taken from the “floor to the top of the upholstery under static conditions, without compression or deflection in the transfer surface ….”⁹ 

The Access Board’s proposal also explained that it is considering requiring in the final standards that the height of transfer surfaces be adjustable from 17 inches minimum to 25 inches maximum during patient transfer. In support of the alternative proposal, it cites ANSI/AAMI HE75¹⁰ and the Wheeled Mobility Anthropometry Project.¹¹ The results of this study recommended adjustable heights, with an increased maximum height above 19 inches, be provided in order to better accommodate users of powered wheelchairs and scooters. During the committee hearings, the manufacturers accepted that this would be appropriate and offered 19-inch to 25-inch adjustable height through powered tables.

The subcommittee’s recommendation appropriately balances the two proposed alternatives included in the Access Board’s proposed rule. Therefore, the Access Board should adopt the subcommittee’s recommendation provider for continuous adjustability of the height of the transfer surface between 19 and 25 inches.

A Minimum Highest Point standard of 19 Inches is Consistent with Existing Accessibility standards

Current accessibility standards and regulations generally consider a transfer surface height of 19 inches accessible. For example:

Nineteen-inch pool lift seats are accessible:

1009.2.4 Seat Height. The height of the lift seat shall be designed to allow a stop at 16 inches (405 mm) minimum to 19 inches (485 mm) maximum measured from the deck to the top of the seat surface when in the raised (load) position.

Nineteen-inch water closet and toilet seats are accessible:

604.4 Height. The height of water closet seats shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum above the floor, measured to the top of the seat. Seats shall not be sprung to return to a lifted position.¹²

Likewise, 19 inch high benches are accessible:

903.5 Height. The top of the bench seat shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum above the floor, measured to the top of the seat.¹³ 

Nineteen-inch high bathtub seats are accessible:

610.2 Bathtub Seats. The height of bathtub seats shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum above the bathroom floor, measured to the top of the seat. Removable in-tub seats shall be 15 inches (380 mm) minimum and 16 inches (405 mm) maximum in depth. Removable in-tub seats shall be capable of secure placement. Permanent seats shall be 15 inches (380 mm) minimum in depth and shall extend from the back wall to or beyond the outer edge of the bathtub. Permanent seats shall be positioned at the head end of the bathtub.¹⁴ 

Nineteen-inch high shower compartment seats are accessible:

610.3 Shower Compartment Seats. The height of shower compartment seats shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum above the bathroom floor, measured to the top of the seat. In transfer-type and alternate roll-in-type showers, the seat shall extend along the seat wall to a point within 3 inches (75 mm) of the compartment entry. In standard roll-in-type showers, the seat shall extend from the control wall to a point within 3 inches (75 mm) of the compartment entry. Seats shall comply with Section 610.3.1 or 610.3.2.¹⁵ 

Nineteen-inch high amusement park rides are accessible:

1102.5.2 Transfer Height. The height of amusement ride seats designed for transfer shall be 14 inches (355 mm) minimum and 24 inches (610 mm) maximum measured from the surface of the load and unload area.¹⁶ 

As mentioned above, a minimum standard of 19 inches at the highest point of a table or chair is not the same thing as the transfer surface height experienced by patients because the front edge of currently available tables is lower than the highest measured point. However, the fact that a nineteen-inch height is so widely accepted by existing accessibility standards for various types of benches and chairs strongly commends maintaining the standard for medical diagnostic equipment as the minimum standard for accessible examination tables and chairs. This is particularly the case because of the manner in which medical diagnostic equipment is used. Unlike toilets, bench seats, and bathtub seats, where usability may require constant contact of one’s feet with the floor for stability or require free use of one’s hands, in most cases medical examination tables and chairs will be raised substantially off of the floor to accommodate caregiver access to patients. Additional requirements of the proposed standards for arm supports provide additional security once an individual has made a successful transfer.

An Increasing Number of Health Care Providers are Transitioning to Adjustable Height Tables

In 2012, approximately 25 percent of examination tables sold in the U.S. are at about a 19-inch low height.¹⁷ This is a significant increase over the 17 percent of adjustable height tables sold in 2005. While manufacturers of tables and chairs understand that lower heights may be desirable, no manufacturer has been able to design and produce an examination table or chair that can reach a height lower than 19 inches uncompressed at the highest point on the table or chair. It is unclear when such a table or chair could be available.

If adopted by the Access Board, a recommendation of 19-inch maximum height will build on the growing percentage of providers voluntarily purchasing accessible, adjustable height tables, at 25 percent today.¹⁸ Conversely, if a new standard lower than 19 inches is established, thereby deeming all current adjustable tables inaccessible, the entire U.S. health system will be forced to begin at 0 percent accessible.

Figure 4: Sales percentages of fixed height versus manual medical tables

Available Data do not Support Departing from the Currently Accepted Standard of 19 Inch Transfer Surface Height

The Medical Diagnostic Equipment Technical Advisory Committee appropriately tried to determine what the optimal accessible transfer surface height is based on available data. In particular, the Advisory Committee spent a great deal of time discussing the Wheeled Mobility Anthropometry Project.¹⁹ In that study, which the U.S. Access Board commissioned, Dr. Steinfeld served as the lead investigator. The Wheeled Mobility Anthropometry project did not study optimal transfer surface heights or the ability of wheeled mobility device users to transfer independently from their mobility device onto an examination table or chair. Instead, the study measured the physical characteristics of people who use wheeled mobility devices and some of the characteristics of those devices.

In evaluating data about seat height, we must be sure to take into account the relevant transfer height from the wheelchair. Dr. Steinfeld’s study measured the rear compressed seat height of the wheeled mobility device with the user seated in it. For transfer purposes, however, the most relevant height is the wheelchair front edge. Unfortunately, Dr. Steinfeld did not measure the height of those same users' front wheelchair edges.

There is a recognized international standard defining various measurements of wheelchairs: ISO 7176-7:1998 Wheelchairs — Part 7: Measurement of seating and wheel dimensions. Figures 6 and 7 below are selected screenshots from this international standard. These illustrations identify several key measurements. The most important illustrations for present purposes are "seat plane angle," "effective seat depth," and "seat surface height at the front edge." The standard focuses on measurement procedure so it does not prove any actual measurements. However, as the images below make clear, the seat reference plane and effective seat depth will dictate the difference between the seat surface height at the front edge and the height of the seat at the rear of the wheelchair. Note further that wheelchair height measurements generally do not take into account the height of the cushion, which the consumer will need to clear at the front edge to enable a successful transfer.

In addition, section 4 of the Paralyzed Veterans of America’s Guide to Wheelchair Selection²⁰ also illustrates the distinction between the following heights:

…the seat surface height at the front edge (which excludes the effect of a seat cushion, typically measuring 2-4" in depth), the seat height at the rear of the seated surface, and the relevant transfer surface height for clearing the seat cushion.²¹

Therefore, the U.S. Access Board should not infer the seat surface height at the front edge is the same as the seat height measured in Dr. Steinfeld’s study. However, these illustrations used in measuring individuals for manual wheelchairs indicate that the U.S. Access Board cannot use the Steinfeld data to make a direct assessment of the table height needed to accommodate wheelchair users effectively.

Based on figures 5-7 below, a 17-inch rear compressed height measured by Steinfeld could easily correspond with a 20- or 21-inch uncompressed seat surface height at the front edge. This could in turn mean that individual users that Steinfeld measured below 19 inches would be able to transfer comfortably to a table surface for which the highest uncompressed surface is 19 inches.

Note further in figure 5 that the rear seat height is considerably lower than the height of the wheelchair wheels, which typically measure 22-26 inches. Any transfer from the rear of the chair would require the user to transfer up and over the wheelchair wheel, again, well above a minimum low-range height of 19 inches.

In addition, a second study commissioned by the U.S. Access Board and evaluated by the Advisory Committee (the Pittsburgh study²²) determined that manual wheelchair-users, who are generally the users most likely to have the lowest seated heights, are generally able to accommodate a 2-inch difference in height between one’s wheelchair and a transfer surface. Consequently, even if one posited that the Steinfeld study finding of 17 inches at the rear of the seat compressed corresponded to an uncompressed height of 17 inches at the front edge of the wheelchair, the maximum height of 19 inches at the highest point of a table or chair transfer surface would still fall within the 2-inch differential identified by the Pittsburgh study as accessible to most manual wheelchair users.

Figure 5: Adapted diagram from the “Paralyzed Veterans of America’s Guide to Wheelchair Selection” showing difference in measured height between Steinfeld report, wheelchair manufacturer’s height per ISO 7176-7, and the uncompressed upholstery measurement height.

Figure 6: Wheelchair manufacturer’s height and seat construction types (showing variation in compression when person’s weight is applied) per ISO 7176-7

Figure 7: Wheelchair manufacture standardized measurements per ISO 7176-7

Chairs with/without Footrests:

With a 17” transfer height, chairs with footrests, which the patient rests their feet on, such as those used in Otolaryngology, Ophthalmology, Plastic Surgery and others would not be comfortable to sit in for a large number of patients. Domestic UL and international IEC standards dictate a 2” clearance from the floor to the bottom of the footrest. And, with a minimal 1” thick footrest plate, the distance from the top of footrest to the top of the seat would be just 14”. Anthropometric data suggest the heel to popliteal dimension, without shoes, of males is 17.5” and that of females is 15.9” in the 50th percentile. Contact with the back of the thigh and/or the rear of the knee with the top front portion of the seat is vital for patient comfort and is especially important for maintenance of knee and thigh position of a disabled person who may lack control of his/her legs.

Chairs with no footrest plate and only a breaking knee legrest have similar problems with a short legrest portion also. Patient comfort in the entry/exit position can be compromised even after the chair is raised and the back lowered because of the length of the chair top in the supine position. Even with the addition of a flip-up or slide out footrest/legrest extension, the total length of the average knee break chair is estimated to be 60“, and only be able to be a maximum of approximately 68” with extension. We estimate the addition of a manual extension of the footrest could add as much as $750 (15%). An electrical or automatic extension could be a $1300 (26%) addition to the net cost of either a chair with a footrest plate or to one without the plate, which only extends the legrest or calf portion. These chairs would have to have an electrical interlock installed in them to protect the chair and patient from the chair being lowered with the legrest extended. These kinds of additional adjustments and added protection controls tend to discourage the operator from using them and thus the patients could instead be forced to endure a medical procedure in uncomfortable positions.

Adoption of a 19 Inch Height Minimizes Costs to Health Care Providers

In the absence of clear data commending a departure from the existing broadly accepted transfer surface height maximum of 19 inches, information related to costs is especially critical to take into account in determining the minimum standard for medical examination tables and chairs. We estimated the costs of various examination table heights under consideration by the Medical Diagnostic Equipment Technical Advisory Committee using third-party data that represents approximately 80 percent of all distributed examination tables sold in the United States.²³ 

To determine the total number of examination rooms in the United States, we reviewed the CDC National Ambulatory Care Survey, and found that there are approximately 639,000 exam rooms in the United States today.

From this total number, and based on historic trends, we estimate that physicians will build new, or remodel existing, exam rooms at a rate of 4 percent each year, but the total number of examination rooms will remain unchanged from year to year.

Also based on historic trends, we estimate that physicians will replace equipment in 7 percent of their examination rooms each year, including new and replacement medical tables. We also estimate that the average annual inflation rate will be 3% over the next ten years.

Benefits and Costs: Overview

Based on our analysis, we determined that transfer surface height requirements lower than 19 inches would increase the cost of designing and manufacturing examination tables, reduce the rate of adoption of accessible equipment, and increase the health provider’s cost of purchasing accessible equipment.

While we estimate that adopting a lower-range requirement of 19 inches, health care providers will experience a 24 percent price increase. This means that a $5,000 adjustable-height examination table purchased today would cost approximately $6,200 after the Access Board adopts the requirements for knee-crutches and transfer supports because health care providers will need to retrofit existing tables and chairs with the required equipment. The price of that same table would be 39 percent higher than the cost of today’s examination tables if the height standard were lower than 19 inches.

Cost of Equipment

Costs to Lower Minimum Table Height

To be useful for its intended purpose, examination tables and chairs must maintain a high height of at least 32 inches, so that the health care provider has clinical access to the patient. In fact, 37 inches is the standard high height today for OB/GYN examinations. The need to reach heights above 32 inches interferes with efforts to lower the transfer surface height. The mechanical system necessary to raise the table are located in the base of the table, beneath the seating surface. As the difference between the required low-height and the necessary high-height for health care providers’ increases, the mechanics necessary to achieve that adjustable range become more complex and expensive.

Figure 8: Range of medical table heights

In addition, we took the costs of other requirements that the Access Board is likely to adopt into account. Based on currently marketed products, we estimate the following costs:

• Transfer Supports (TS): $500 - $1,000 (M301.3.1)

• Leg Supports (LS): $700 - $1,100 (M301.3.2)

Therefore, the average “upgrade” cost to add transfer and leg supports would be approximately $1,650.

Scoping Scenarios: Range of Possibilities

We do not know what mandates may be put in place in the future to require Access Board standards. However, the U.S. Access Board’s decisions regarding technical requirements for equipment will significantly affect the costs on health care providers and examination table and chair manufacturers.

To illustrate this effect, we considered a broad range of scenarios. For example, if a national mandate were to require one accessible table per physician work area of five exam rooms (a typical physician practice set-up today), that would require a 20 percent adoption rate. We also considered a 100 percent adoption rate to show the full range of potential costs.

If the market adoption rate of adjustable tables were to match a requirement that one table of every five tables meet a 19 inch lower adjustable range when facility construction occurs, there would be a drop in patient access to compliant examination tables of 17% and a savings of $420 million over ten years. However, if the market adoption rate were to match a requirement that ALL new tables meet a 19-inch lower adjustable range when new construction or remodeling occurs, then accessibility would increase by 17% at a cost to health care providers of $1.38 billion over a ten-year period.

By contrast, if the market adoption rate matched a requirement to make one table of every five tables meet an adjustable range lower than 19 inches, there would be a reduction in availability of accessible tables by 35% for a savings of $530 million over ten years. However, if the requirement were to make ALL new tables meet an adjustable range lower than 19 inches when new construction or remodeling occurs, then accessibility would decrease by 1% at a cost to health care providers of $1.52 billion over a ten-year period.

The table and chart below illustrate these examples.

Table 2: Costs of Scoping Scenarios

Figure 9: Summary of cost and implementation scenarios of Table 2

Therefore, while establishing these requirements will result in significant costs to health care providers, establishing a lower adjustable height requirement of 19 inches will maximize the percentage of accessible tables and will cost less than requiring an adjustable height lower than 19 inches.

 

Notes 

^5. Medical table install base derived from U.S. medical distribution sales data, as provided by Global Healthcare Exchange (GHX), found at http://www.ghx.com/product-pages/solutions/supplier-solutions/sales-data-analytics.aspx

^6. See M301.2.1 and M302.2.1.

^7. See Architectural and Transportation Barriers Compliance Board. Notice of Proposed Rulemaking: Proposed Accessibility Standards for Medical Diagnostic Equipment. February 8, 2012.

^8. Ibid.

^9. Ibid.

^10. Ibid, citing ANSI/AAMI HE 75, section 16.4.4. ANSI/AAMI HE75 recommends that the height of patient support surfaces "should be easy to adjust (ideally, powered) to suit the needs of health care professionals and patients." ANSI/AAMI HE75 further recommends that the height of patient support surfaces "should be adjustable to a position high enough to accommodate tall health care providers and the range of medical procedures that could occur . . . [and] to a position low enough [19 inches maximum] to allow for the comfort of providers who choose to work in a seated position, to enable patients to keep their feet on the floor while seated, and to accommodate patients who need to transfer laterally between the platform and a chair or wheelchair alongside."

^11. See Analysis of Seat Heights for Wheeled Mobility Devices at: http://udeworld.com/analysis-of-seat-height-for-wheeled-mobility-devices. The seat heights ranged from 16.3 inches to 23.9 inches for manual wheelchair users; 16.2 inches to 28.9 inches for power wheelchair users; and 18.8 inches to 25.3 inches for scooter users. Seat heights for males were typically higher than for females. Thirty (30) percent of male manual wheelchair users and 6 percent of male power wheelchair users had seat heights equal to or less than 19 inches. All the male manual wheelchair users and 92 percent of the male power wheelchair users had seat heights equal to or less than 25 inches. Thus, transfer surfaces that are adjustable from 17 inches minimum to 25 inches maximum during patient transfer accommodate significantly more patients who use mobility devices.

^12. See Accessible and Usable Buildings and Facilities, ICC/ANSI A117.1-2009.

^13. Ibid.

^14. Ibid.

^15. Ibid.

^16. Ibid.

^17. Medical table install base derived from U.S. medical distribution sales data, as provided by Global Healthcare Exchange (GHX).

^18. Some tables may require installation of a modified top to meet the 19” standard but would not require changing out the installed base.

^19. See Analysis of Seat Heights for Wheeled Mobility Devices at: http://udeworld.com/analysis-of-seat-height-for-wheeled-mobility-devices. The seat heights ranged from 16.3 inches to 23.9 inches for manual wheelchair users; 16.2 inches to 28.9 inches for power wheelchair users; and 18.8 inches to 25.3 inches for scooter users. Seat heights for males were typically higher than for females. Thirty (30) percent of male manual wheelchair users and 6 percent of male power wheelchair users had seat heights equal to or less than 19 inches. All the male manual wheelchair users and 92 percent of the male power wheelchair users had seat heights equal to or less than 25 inches. Thus, transfer surfaces that are adjustable from 17 inches minimum to 25 inches maximum during patient transfer accommodate significantly more patients who use mobility devices.

^20. Available at http://www.wheelchairnet.org/WCN_ProdServ/Docs/PDF/AXbook_Sec4a.pdf

^21. Ibid.

^22. Human Engineering Research Laboratories, University of Pittsburgh, The Impact of Transfer Set-Up on the Performance of Independent Transfers: Final Report. Available at: http://herl.pitt.edu/ab/transfer_assessment_report.pdf (visited May 22, 2013).

^23. Medical table install base derived from U.S. medical distribution sales data, as provided by Global Healthcare Exchange (GHX), found at http://www.ghx.com/product-pages/solutions/supplier-solutions/sales-data-analytics.aspx

How to Measure Transfer Surface Height

Regardless of the final decision on the low height measurement, the Subcommittee agreed that the height of the transfer surface would be measured in its uncompressed state.

Many medical examination rooms are equipped with fixed height examination tables, with a typical 32-inch seat height. However, these fixed heights tables do not allow for independent transfer of patients who use wheeled mobility devices (WMD). To solve this problem, manufacturers have designed adjustable height examination tables to work with a variety of WMD’s. Manufacturers designed the shape of the seat for these tables to meet both patient accessibility and clinical needs, resulting in a complex, contoured shape.

Because of these complex shapes, it is necessary to create a standard method by which to measure table seat dimensions. These proposed measurement techniques would apply equally to tables (M301) and chairs (M302).

Several necessary features determine the shape of an examination table seat:

The perineal cut-out provides access to the perineum for gynecological and urological examinations.

The corner radii allow for closer wheelchair positioning to facilitate independent transfer by minimizing gaps. The corner radii also eliminate seams in the upholstery, which improves longevity, but more importantly also improves asepsis and infection control.

Bolsters improve patient comfort and stability when seated on table. Note that the design minimizes the bolsters at the front half of the seat in order to promote ease of transfer.

Note that these features are widely used in both tables and chairs. Beds, stretchers, and other types of equipment will have unique features that determine the shapes of their patient support surfaces.

Figure 10: Features of the countered shape of a medical examination table

The design of the corner radii allows closest possible position for wheelchair transfers, minimizing potential gaps and improving the patient’s ability to transfer independently.

In the diagram below, the upper wheelchair illustrates a typical side transfer, which may optionally utilize a transfer board. The lower wheelchair illustrates a typical diagonal transfer.²⁴

 

Figure 11: Corner radii of a medical examination table

The depth and width are measured along the centerlines of the seat, and the height from the floor to the highest point of the transfer surface:

 

• The depth is measured between the perineal cutout and the hinge point at the back of the seat.

• The width measured across the seat at the midpoint between the seat hinge and the front of the seat.

• The height is measured at the highest point of the seat, inclusive of bolsters, with the foam in an uncompressed state. Note that this measurement would be at the highest point on the seating surface, which may not necessarily be at the centerline of the seat.

Notes 

^24. Examples of such transfers can be viewed here: http://www.youtube.com/watch?v=qivOb_V6IgA 

Transfer Supports Location and Configuration M301.3 and M302.3

Location of the transfer supports shall be a minimum of 6 inches to a maximum of 19 inches from the top of the transfer surface and ensure that any entrapment issues are addressed as per 606.1.252. The length of the transfer support shall be a minimum of 15 inches long and positioned so that the transfer support overlaps the length of the transfer surface by 80% at a maximum distance from transfer surface of 1 ½ inches. The shape (contours and curves along length for ergonomics, not cross sectional profile) was kept open to give manufacture flexibility in the design as the direction of positioning (i.e. horizontal, angled, etc.). Transfer supports shall be mounted on both sides of the transfer surface and must be movable or removable so they can be out of way of transfer. The rating is for 250 pounds of force in direction of use as per IEC 60601 & BIFMA.

We recommended height adjustability of the transfer support but did not mandate it to give manufactures design options.

Gripping Surface Cross Section and Clearances M301, M302, and M305.2

Gripping surface for transfer supports shall be free of sharp or abrasive elements and shall have rounded edges per ADA and ABA 2004 Guidelines Section 609.5. Interruptions along the bottom of the transfer support gripping surface will not obstruct more than 20% of its length per ADA and ABA 2004 Guidelines Section 505.6. The transfer supports shall be located at a maximum distance from transfer surface of 1 ½ inches.

Armrests M302.3.2

Armrests are recommended but not required. If provided armrests cannot interfere with transfer supports during the transfer. Dual transfer support/armrest mechanisms are allowed as long as the transfer support meets all of the requirements for transfer supports.

Notes 

^1. The Impact of Transfer Setup on the Performance of Independent Transfers: Final Report. Presentation to US Access Board. Washington, DC. 2011

^2. D’Souza, Clive and Edward Steinfeld, IDeA Center. Analysis of Seat Height for Wheeled Mobility Devices. 2011.

^3. The Impact of Transfer Setup on the Performance of Independent Transfers: Final Report. Presentation to US Access Board. Washington, DC. 2011

^4. Jensen, M.P., Molton, I.R., Groah, S.L., Campbell, M.L., Charlifue, S., Chiodo, A., Forchheimer, M., Krause, J.S., & Tate, D. (2011). Secondary Health Conditions in Individuals Aging with SCI: Terminology, Concepts, and Analytic Approaches. Spinal Cord, 50(5): 373-378.

Groah, S.L., Charlifue, S., Tate, D., Jensen, M.P., Molton, I.R., Forchheimer, M., Krause, J.S., Lammertse, D.P., & Campbell, M. (2012). Spinal Cord Injury and Aging: Challenges and Recommendations for Future Research. American Journal of Physical Medicine & Rehabilitation, 91(1): 80. doi: 10.1097/PHM.0b013e31821f70bc. Available from: http://journals.lww.com/ajpmr/Abstract/2012/01000/Spinal_Cord_Injury_and_Aging__Challenges_and.10.aspx. Accessed December 18, 2012.

Turk M. Secondary conditions and disability. In: Field MJ, Jette AM, Martin L (eds). Workshop on disability in America. A new look. Summary and background papers. Board on Health Sciences Policy, Institute of Medicine of the National Academies, The National Academies Press: Washington DC, 2006, pp. 185–193.

Kemp, B.J., & Mosqueda, L. (Eds.) (2004). Aging with a Disability: What the Clinician Needs to Know. Baltimore, MD: Johns Hopkins University Press.

Kailes, J. (2000). Health, Wellness and Aging with Disability, KAILES - Publications, http://www.jik.com/resource.html, jik@pacbell.net This email address is being protected from spambots. You need JavaScript enabled to view it. .

Kailes, J. (1995). "Midlife Cripdom: Getting Fewer Miles per Gallon?" The Disability Rag 16(4).

Kailes, J. (2001). Aging with Disability - Good News and Bad News. Western U-View. XX: 17.

^5. Medical table install base derived from U.S. medical distribution sales data, as provided by Global Healthcare Exchange (GHX), found at http://www.ghx.com/product-pages/solutions/supplier-solutions/sales-data-analytics.aspx

^6. See M301.2.1 and M302.2.1.

^7. See Architectural and Transportation Barriers Compliance Board. Notice of Proposed Rulemaking: Proposed Accessibility Standards for Medical Diagnostic Equipment. February 8, 2012.

^8. Ibid.

^9. Ibid.

^10.Ibid, citing ANSI/AAMI HE 75, section 16.4.4. ANSI/AAMI HE75 recommends that the height of patient support surfaces "should be easy to adjust (ideally, powered) to suit the needs of health care professionals and patients." ANSI/AAMI HE75 further recommends that the height of patient support surfaces "should be adjustable to a position high enough to accommodate tall health care providers and the range of medical procedures that could occur . . . [and] to a position low enough [19 inches maximum] to allow for the comfort of providers who choose to work in a seated position, to enable patients to keep their feet on the floor while seated, and to accommodate patients who need to transfer laterally between the platform and a chair or wheelchair alongside."

^11.See Analysis of Seat Heights for Wheeled Mobility Devices at: http://udeworld.com/analysis-of-seat-height-for-wheeled-mobility-devices. The seat heights ranged from 16.3 inches to 23.9 inches for manual wheelchair users; 16.2 inches to 28.9 inches for power wheelchair users; and 18.8 inches to 25.3 inches for scooter users. Seat heights for males were typically higher than for females. Thirty (30) percent of male manual wheelchair users and 6 percent of male power wheelchair users had seat heights equal to or less than 19 inches. All the male manual wheelchair users and 92 percent of the male power wheelchair users had seat heights equal to or less than 25 inches. Thus, transfer surfaces that are adjustable from 17 inches minimum to 25 inches maximum during patient transfer accommodate significantly more patients who use mobility devices.

^12.See Accessible and Usable Buildings and Facilities, ICC/ANSI A117.1-2009.

^13. Ibid.

^14. Ibid.

^15. Ibid.

^16. Ibid.

^17. Medical table install base derived from U.S. medical distribution sales data, as provided by Global Healthcare Exchange (GHX).

^18. Some tables may require installation of a modified top to meet the 19” standard but would not require changing out the installed base.

^19. See Analysis of Seat Heights for Wheeled Mobility Devices at: http://udeworld.com/analysis-of-seat-height-for-wheeled-mobility-devices. The seat heights ranged from 16.3 inches to 23.9 inches for manual wheelchair users; 16.2 inches to 28.9 inches for power wheelchair users; and 18.8 inches to 25.3 inches for scooter users. Seat heights for males were typically higher than for females. Thirty (30) percent of male manual wheelchair users and 6 percent of male power wheelchair users had seat heights equal to or less than 19 inches. All the male manual wheelchair users and 92 percent of the male power wheelchair users had seat heights equal to or less than 25 inches. Thus, transfer surfaces that are adjustable from 17 inches minimum to 25 inches maximum during patient transfer accommodate significantly more patients who use mobility devices.

^20. Available at http://www.wheelchairnet.org/WCN_ProdServ/Docs/PDF/AXbook_Sec4a.pdf.

^21. Ibid.

^22. Human Engineering Research Laboratories, University of Pittsburgh, The Impact of Transfer Set-Up on the Performance of Independent Transfers: Final Report. Available at: http://herl.pitt.edu/ab/transfer_assessment_report.pdf (visited May 22, 2013).

^23. Medical table install base derived from U.S. medical distribution sales data, as provided by Global Healthcare Exchange (GHX), found at http://www.ghx.com/product-pages/solutions/supplier-solutions/sales-data-analytics.aspx

^24. Examples of such transfers can be viewed here: http://www.youtube.com/watch?v=qivOb_V6IgA