2003 Conference Proceedings

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ERGONOMIC ASSESSMENT OF LOW VISION/BLIND ASSISTIVE TECHNOLOGY

Presenter
Michael Parker, MSME, Rehabilitation Engineer
Access Ingenuity
3635 Montgomery Dr.
Santa Rosa, CA 95405
Phone: 707-579-4380
FAX: 707-579-4273
Email: michaelp@accessingenuity.com

Alec F. Peck Ph.D.
Assoc. Professor
Lynch School of Education
Boston College
Chestnut Hill MA 02467
Phone: 617 552 3149
FAX: 617 552 8419
Email: peck@bc.edu

Mark Uslan, AFB Tech Director
American Foundation for the Blind
949 3rd AVE., SUITE 200
Huntington, WV 25701
Phone: 304-523-8651
Fax: 304-523-8656
Email: mulsan@afb.net

Introduction:

From both formal research and widespread anecdotal reporting, it has been recognized that many (if not most) blind or low vision users of assistive technology devices compromise good ergonomic practice when using their devices. For example, the authors found in previous work that 70% of the blind or low vision users of a Video Magnifier (CCTV) at work reported that they experience some symptoms of musculoskeletal fatigue - a type of repetitive strain injury. At the same time, these same people noted that they like their CCTVs and they can't do their jobs without them. In order to work through the fatigue they experience, 40% stop after only 10 minutes or less of use per sitting. Others just "live with it" in order to get their job done. Work related musculoskeletal disorders and fatigue is an acknowledged problem that impacts a large percentage of workers. Depending on the prevalence and degree to which blind or low vision users of assistive technology compromise good ergonomics when using their devices could have a significant impact on the development of musculoskeletal disorders and fatigue - and subsequent loss of productivity.

Research Study:

A research study was devised to investigate the ergonomic risk factors that can lead to musculoskeletal disorders among blind and low vision users of assistive technology and specifically determine the degree to which blind or low vision users of assistive technology compromise their body postures to work with their equipment.

The research study used the Rapid Upper Limb Assessment Method (RULA) developed by McAtamney and Corlett (Applied Ergonomics, 1993) to assess the biomechanical and postural loading on the low vision/blind users of assistive technology. The ergonomic assessment procedure (RULA) particularly focuses on the neck, trunk, and upper limbs - the same areas of fatigue which were reported by CCTV users in the authors' previous work.

RULA was designed as an observational ergonomic assessment technique in which observed biomechanical and postural loading is compared to known ergonomic risk factor criteria which has been found to contribute to the development of musculoskeletal disorders and fatigue. The results of the RULA assessment give an action level required to reduce ergonomic risks for each of the tasks (or use of assistive technology) assessed. There are four action levels reported by RULA:

Results:

A total of 32 assessments were completed for the tasks associated with the usage of seven unique blind or low vision assistive technology devices. Out of these 32 assessments, a high number resulted in elevated action levels as shown in Table 1, below.

Table 1: Summary RULA Assessment Data

Device Assessed Number of Assessments RULA Action Level (Average)
CCTV - In-Line 4 4
CCTV - Side-by-side 2 3
Screen Reader 10 3
Screen Magnifier 8 3
Electronic Notebook w/ Braille Display 3 4
Electronic Notebook w/oBraille Display 2 3
Scanner 3 4

As can be seen from the table above, all of the RULA Action Level results fell into the two top action level categories - suggesting that further investigation and changes be made to address the ergonomic issues identified and that these changes should be addressed soon, if not immediately, to prevent the development of musculoskeletal disorders and fatigue. This result validates the authors' previous finding that 70% of people who use CCTVs report musculoskeletal disorders and fatigue. It also confirms that the same results are experienced by blind or low vision users of computers.

vThe one positive outcome of the assessments was the finding that most of the elevated action levels related to how the user was interfacing with the assistive technology, not necessarily the assistive technology itself. For example, many low vision users were found to lean in towards their monitor - thereby compromising their upper body posture. This situation could be corrected with ergonomically adjusted equipment.

Conclusion:

The above results confirm our suspicion that blind and low vision users of assistive technology devices compromise good ergonomic practice when using their devices.

However, it was also found that the assistive technology only contributed to the problem - assistive technology devices were not the only factor leading to compromised body postures. In fact, in most cases the researchers found that simple ergonomic adjustments to the workstations would result in substantial reduced ergonomic risk factors as reported on the RULA ergonomic assessments.

Further research is needed to identify and validate successful solutions to the problems identified. The authors also recommend the development of training and tools to disseminate information about ergonomics and the possible side effects of using assistive technology to the blind and low vision community.


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