Development of a therblig-based evaluation methodology for accessible product: a case study of spinal-cord impaired users

Abstract

Purpose

This study proposes a therblig-based evaluation technique as a new accessibility tool for physical products like home appliances that spinal cord injured users occasionally use.

Material and Methods

This study recruited nine spinal cord injured users for the interview and observation regarding home appliance usage and analytically structured their usage behaviors using therbligs. The therblig notations eventually referred to actual and potential accessibility issues that spinal cord injured users would encounter when using the home appliances.

Results

The primary therblig operations causing accessibility issues for spinal cord injured users were 'reach,' 'move,' 'grasp,' 'position,' and 'use’, corresponding to their disability characteristics. In addition, this study proposed a new effective therblig called “hook,” which is suitable for better representation of user behavior and accessibility evaluation of spinal cord users.

Conclusion

This study provided an interaction-based accessibility evaluation technique, which is easy to learn and apply, especially for physical products.

IMPLICATIONS FOR REHABILITATION

• The therblig-based accessibility evaluation method describes the user behavior on a micro-scale and localizes a problematic operation throughout the task process during home appliance usage.

• Reach, Move, Grasp, Position and Use were the primary problematic therblig operations regarding home appliance usage of spinal cord injured users, resulting in low accessibility.

• A new therblig 'hook’ was developed to describe the user behavior of spinal cord injured users.

• Therblig evaluation offers a more standardized, easy-to-learn accessibility evaluation method that does not require expertise but provides the latent needs of users.

Keywords:

• Accessibility evaluation
• therbligs
• home application usage
• spinal cord injured users

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was supported by the National Research Foundation of Korea (NRF) funded by the Republic of Korea's MSIT (Ministry of Science and ICT) (No. NRF2021R1A2C201250112).