From carrying grocery bags to holding onto handles on the bus, there are a variety of situations where one or both hands are busy, hindering the vision of ubiquitous interaction with technology. Voice commands, as a popular hands-free alternative, struggle with ambient noise and privacy issues. As an alternative approach, research explored movements of various body parts (e.g., head, arms) as input modalities, with foot-based techniques proving particularly suitable for hands-free interaction. Whereas previous research only considered the movement of the foot as a whole, in this work, we argue that our toes offer further degrees of freedom that can be leveraged for interaction. To explore the viability of toe-based interaction, we contribute the results of a controlled experiment with 18 participants assessing the impact of five factors on the accuracy, efficiency and user experience of such interfaces. Based on the findings, we provide design recommendations for future toe-based interfaces.

翻译：从提购物袋到在公交车中抓握扶手，多种场景下人们的一只或双手均处于忙碌状态，阻碍了普适交互技术的应用前景。作为广受欢迎的无手替代方案，语音指令在环境噪声和隐私问题方面存在局限。为此，研究者探索了身体各部位（如头部、手臂）的运动作为输入模态，其中基于脚部的技术特别适用于无手交互场景。然而，此前研究仅将脚部视为整体运动单元。本文提出，脚趾实际上具备可被利用于交互的额外自由度。为验证基于脚趾交互的可行性，我们开展了一项包含18名参与者的受控实验，系统评估了五个因素对该类交互接口准确性、效率及用户体验的影响。基于实验发现，我们为未来脚趾交互接口的设计提供了建议。