P-19　Usability testing of 3D-printed short thumb orthoses for clients with CMC pain

抄録

Traditionally, clients with CMC pain wear short thumb orthoses to immobilize the thumb and relieve joint pain. The clinical effectiveness of such orthoses is supported by evidence. The traditional short thumb orthosis is made of low-temperature thermoplastic material. The maker contours thermoplastic material to fit the user’s hand shape at low temperature (about 50- 60⁰C). Although an individualized orthosis is made for each user, the material is hard and the structure is insubstantial. Therefore, some disadvantages have been found with regard to wearing short thumb orthoses. For example, the area contacting the thumb is hard and causes discomfort, the seam on the dorsal side of the thumb orthosis is insubstantial, and movement is limited when the wearer performs daily activities that require fine motor skills.

This research team developed a new 3D-printed short thumb orthosis that is expected to overcome the discomfort and inconvenience of the traditional orthosis. The hand shape is first captured by a 3D scanner, and the maker sketches the 3D printed short thumb orthosis according the digitized 3D hand shape. The orthosis is then molded with flexible filaments by a 3D printer. With this method, the orthosis not only can be individualized for each user to immobilize the CMC joint but also provides comfort and soft contact with the thumb.

In this study, the usability, including the effectiveness, efficiency, and satisfaction, of the 3D-printed short thumb orthosis was investigated. Three clients with CMC pain were recruited for the study. They were asked to complete three tests: the Purdue Pegboard Test (for dexterity performance), the Taiwanese version of the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST-T) (for self-perceived satisfaction), and electromyography measurement of four forearm muscles (for objective measurement of forearm muscle loading). All subjects completed the three tests in both traditional and 3D-printed orthoses conditions.

The results indicated that the dexterity performance and the self-perceived satisfaction was better in the 3D-printed condition than in the traditional condition. However, the durability item in the QUEST-T was poor in the 3D-printed condition than in the traditional condition. The forearm muscle loading did not differ in the traditional and 3D-printed orthoses conditions. To improve usability, the researchers will design different styles of 3D-printed orthoses to improve the durability in the future.