Nail clipper ergonomic evaluation and redesign for the elderly Hsin-Chieh Wu a, * , Min-Chi Chiu b , Cheng-Heng Hou a a Department of Industrial Engineering and Management, Chaoyang University of Technology, No.168, Jifong E. Rd, Wufong District, Taichung, 41349, Taiwan, ROC b Department of Industrial Engineering and Management, National Chin-Yi University of Technology, Taichung, Taiwan, ROC article info Article history: Received 24 February 2014 Received in revised form 19 October 2014 Accepted 1 December 2014 Available online 13 December 2014 Keywords: Ageing Product design Usability Computer simulation abstract This study designs and evaluates a new nail clipper for the elderly using ergonomic methods. The nail clipper usage problems and requirements were collected first. After requirement analysis we applied ergonomic simulation in redesigning the nail clipper and developing a pedal plate. A usability test was conducted to evaluate both typical and newly developed nail clippers using 20 elder participants. The dependent measures were the total number of nails clipped, completion time and discomfort and satisfaction subjective ratings. The experimental results indicated that the newly developed nail clipper was superior to the typical one in subjective ratings for discomfort and satisfaction. The performance of the newly-developed nail clipper is similar to that of the typical clipper. Some important nail clipper design implications for the ageing population are discussed. Relevance to industry: With the increase in the elderly population, problems caused by aging have gradually emerged. Aging may cause the elderly inconvenience in using many household objects that are not specifically designed for the elderly. Therefore, industrial designers should try to redesign household objects to enhance living quality for the elderly. This study used nail clipper design as an example to show how to apply ergonomic methods in product design. © 2014 Elsevier B.V. All rights reserved. 1. Introduction The average life expectancy of human beings has increased yearly due to rapid progress in medicine and technology. However, the birthrate in some advanced countries has decreased (Economist, 2010). There is now an ever increasing proportion of elderly in the national population. Taking Taiwan for example, the proportion of elderly in the population was 10.4% in 2008. It is estimated that the proportion of elderly will increase to 14% by 2017 and to 20.1% by 2025. It takes approximately eight years to transform an aging society to a super-aging society, suggesting that the speed of population aging in Taiwan is increasing (Council for Economic Planning and Development, 2008). The problems caused by aging have also gradually emerged in Taiwan. The phe- nomenon of population aging is not only common in Taiwan, but has serious influence in many developed countries around the world. Aging is usually accompanied by physical function decline, i.e., physical inconvenience, such as reduced muscle endurance, joint stiffness and decreased activity. (Harma, 1996). The disability prevalence in activities of daily living (ADL) and instrumental ac- tivities of daily living (IADL) increases with age as well. For IADL, cooking, cutting toenails and doing housework, the functional disability rate rise sharply with the increase in age for Chinese elderly (Tang et al., 1999). Moreover, a high prevalence of foot problems had been reported among aging adults with most of them unable to care their own feet (Ebrahim and Sainsbury, 1981). All of these changes may cause the elderly inconvenience in using many household objects that are not specifically designed for them. Therefore, ergonomists should try to redesign household objects to enhance living quality for the elderly. If aging problems and requirements can be considered in household object design, the elderly can be made more comfortable at home. Taking the nail clipper as an example, it is more difficult for the elderly to clip their own nails compared with young adults (Wu and Hou, 2009). Hand pinch strength decreases with aging and the finger and toenails of the elderly become thicker, harder and more dry (Tsai, 2002). Based on the previous investigation (Wu et al., 2012), most respondents (81.7%) used the “two-point pinch” to clip their fingernails. The thumb and forefinger were the major parts experiencing discomfort. In toenail clipping the * Corresponding author. Tel.: þ886 4 2332 3000x4537; fax: þ886 4 2374 2327. E-mail address: hcwul@cyut.edu.tw (H.-C. Wu). Contents lists available at ScienceDirect International Journal of Industrial Ergonomics journal homepage: www.elsevier.com/locate/ergon http://dx.doi.org/10.1016/j.ergon.2014.12.002 0169-8141/© 2014 Elsevier B.V. All rights reserved. International Journal of Industrial Ergonomics 45 (2015) 64e70