F5-3　Effectiveness of a Rubber Band for Improving the Usability of a Smartphone

Abstract

The size of smartphones has been increasing and many users find them inconvenient to operate. When a user touches an icon that is located on the side away from their hand, at the bottom of the panel, or close to their hand, they may have to stretch, abduct, or bend their thumb, causing discomfort. The situation is extreme when the user inputs letters because the keys are small. By using an accessory such as a ring or hand strap, a user can hold a smartphone in a different posture compared to that used without an accessory so as to operate the smartphone more easily. This study investigates the effectiveness of a rubber-band accessory by measuring the IP-joint and CM-joint angles when a subject touches four keys located at the corners of a Japanese keypad.