An Overview of Smart Shoes in the Internet of Health Things: Gait and Mobility Assessment in Health Promotion and Disease Monitoring
New smart technologies and the internet of things increasingly play a key role in healthcare and wellness, contributing to the development of novel healthcare concepts. These technologies enable a comprehensive view of an individual's movement and mobility, potentially supporting healthy living as well as complementing medical diagnostics and the monitoring of therapeutic outcomes. This overview article specifically addresses smart shoes, which are becoming one such smart technology within the
... uture internet of health things, since the ability to walk defines large aspects of quality of life in a wide range of health and disease conditions. Smart shoes offer the possibility to support prevention, diagnostic work-up, therapeutic decisions, and individual disease monitoring with a continuous assessment of gait and mobility. This overview article provides the technological as well as medical aspects of smart shoes within this rising area of digital health applications, and is designed especially for the novel reader in this specific field. It also stresses the need for closer interdisciplinary interactions between technological and medical experts to bridge the gap between research and practice. Smart shoes can be envisioned to serve as pervasive wearable computing systems that enable innovative solutions and services for the promotion of healthy living and the transformation of health care. Appl. Sci. 2017, 7, 986 2 of 17 and cardiovascular disorders, distinct symptoms reduce motor function and/or cardio-pulmonary capacity, and thereby limit the independence and autonomy of individuals. Even though the disease-causing mechanisms and symptomatic patterns are specific to each disorder, impaired mobility is a typical consequence. This fact makes mobility an important surrogate marker for disease severity, progress, and responsiveness to the prescribed therapies, providing opportunities to assist therapeutic decision making. The continuous, automatic monitoring of sensor-based information on walking ability and mobility is increasingly exploited to support objective assessment for preventative and proactive disease management and diagnostic workup, and to assist with therapeutic decision-making. In this work, we envision to leverage the emerging Internet of Health Things (IoHT)  to enable the application of smart devices for continuous, real-time monitoring. Smart shoes are an attractive form of smart devices for the purpose of mobility assessment for three reasons: (i) smart shoes have a predefined, rigid sensor position on the foot, providing accurate and flexible biomechanical analysis; (ii) smart shoes can be used to monitor gait, a highly stereotype movement that enables the automated assessment of functional biomechanics; and (iii) smart shoes enable a non-obtrusive and non-stigmatizing integration of technology, ultimately improving patient acceptance and long-term adherence. We also envision that the sporting goods industry will produce a growing number of sensor-equipped smart shoes that are capable of monitoring fitness and health conditions. The current limitations of this technology, namely restricted usability to patients, limited battery runtime, and especially restriction to only one shoe model due to a limited availability of instrumentation, will be overcome in the future once this mass-market availability is ensured. Mobility monitoring technologies demand research in sensor-based data acquisition and its subsequent analysis to support objective and clinically relevant gait analysis outside of conventional clinical environments  . The mounting popularity of this research topic is reflected by the annually increasing number of related articles as shown in Figure 1 . Thus, this paper aims to provide an overview of the important engineering aspects of smart-shoe applications in the field of IoHT. It will also highlight the differences and requirements of the related engineering and medical needs (Figure 2 ), which are critical components for effective biomedical engineering solutions.