**1.1 Motivation**

Physical inactivity, particularly among aging adults and home-bound individuals with chronic conditions and/or disabilities, is a major national concern in the United States [1]. Regular physical activity, defined as 150 minutes of moderate physical activity per week [2], supports improved health and decreases the risk of obesity and chronic disease for people of all ages and abilities. Physical exercise also has important benefits for individuals with chronic health conditions such as arthritis [3]; depression [4, 5]; stroke [6]; lower-limb disabilities [7]; fibromyalgia [8, 9]; cardiopulmonary difficulties [10, 11]; multiple sclerosis [12]; Parkinson's disease [13]; and vestibular disorder [14]. In addition to physical benefits, engagement in physical activity provides psychological benefits for these individuals [15, 16]. Despite this evidence, less than half of all adults get the recommended amount of physical activity on a regular basis [17]. This issue becomes extremely serious during Coronavirus (COVID-19) pandemic [18]. The associated economic impact of physical inactivity is significant: annual health-care expenses are estimated at \$860 billion for community-dwelling adults 50 years or older [2] with still additional workforce impacts [19]. These impacts are compounded by the fact that 80 percent of chronic conditions can be prevented or managed with regular physical activity [2]. Therefore, there is an urgent need to develop practical innovative exercise methods that *engage* individuals at all ages, including those with chronic health condition(s) and/or disability, *increase regular physical activity* levels, and *translate to improved health* with optimal functional ability and participation.

As noted above, typical physical activities may not always be feasible for individuals who suffer from disabilities or diseases, and may increase the risk of new and exacerbated chronic health conditions, compounded by advanced age. There is a critical need to tailor physical activity to an individual, based on their underlying capability, health risks, and movement goals. For example, different individuals may wish to strengthen different muscle groups, or have specific movement goals directed by a physical or occupational therapist.

In order to achieve those goals, we propose a **V**ersatile, **I**ndividualized, and **G**enerative **OR**chestrator (**VIGOR**) to motivate the movement of people (particularly those with limited mobility) [20]. To *Help*, *Push*, and *Coach* (**HPC**) users with various chronic health conditions to participate in restorative physical activities in the most effective way, the VIGOR system is designed to adapt to ensure an individualized experience that accounts for the personal, environmental, and social/ cultural characteristics of the user [21]. **Figure 1** compares VIGOR with its competitors. The proposed VIGOR is unique in that it can provide a fully *personalized* user experience. Software products in the industry using virtual technology to encourage engagement in physical activity [23–25] include SaeboVR (www.saebo.com/saeb ovr), Nintendo Wii, and Verapy Therapy VAST (vast.rehab). Similar software products in Academia include OpenSim (opensim.stanford.edu) and QuaterNet (Facebook AI Research). Unlike those products, VIGOR integrates Tai-Chi, the traditional mind–body wellness and healing art [26, 27], with a series of data-driven computing technologies that will provide *customized* restorative physical activities for individuals with a broad range of chronic conditions and functional abilities. Our premise is that a user-friendly movement HPC system that may be conveniently utilized in sitting or standing positions, will empower individuals to increase their regular physical activity levels, and thus, improve health, functional ability, and participation in activities of everyday life. In this way, VIGOR emerges as an

*VIGOR: A Versatile, Individualized and Generative ORchestrator to Motivate the Movement… DOI: http://dx.doi.org/10.5772/intechopen.96025*

#### **Figure 1.**

*Motivation and rationale for the proposed VIGOR system: a comparison between existing systems and VIGOR (online video [22]).*

innovative, individualized and generative fitness modality that demonstrates connection of data, systems, and people for potential clinical benefits [20, 28].

In this research, we propose developing VIGOR within the context of Tai-Chi, a traditional mind–body wellness and healing art [26–28]. While our methods and framework can be applied to multiple exercise approaches, Tai-Chi is ideally suited to people with limited mobility, such as aging population and disabled people. Tai-Chi has documented benefits in improving balance as well as muscle strength, coordination, and endurance in multiple populations [26]. In addition, the lowimpact nature of Tai-Chi is ideal for elderly individuals or groups with neuromusculoskeletal impairments. This exercise has low risks for musculoskeletal injury and joint damage while providing the many benefits of exercise.

While Tai-Chi is proven to have many health benefits, the underlying biomechanics of different choreography tailored to individual patient capabilities are difficult to identify. Knowing the "right" strategy for an individual from a kinematic trajectory alone is difficult without understanding underlying physiology. Biomechanical models can be used to determine the kinetics resulting in a desired kinematic trajectory [29–32], and then to coach the patient to activate the correct muscles to work toward their movement goals. Joint kinetics are more directly mapped to underlying muscular strength and capability compared to joint kinematics [32]. Thus, the incorporation of underlying biomechanics is critical for personalization of training sessions and mobility targets.

#### **1.2 Rationale for the VIGOR system to address aging and chronic disability**

Tai-Chi is characterized by low impact, flowing, and circular movements [13, 27]. The practice of these movements requires coordination and

synchronization of a calm yet alert mind and a relaxed body [15, 16, 21]. It has enormous potential for improving physical and psychological functionality for users in both clinical and non-clinical settings by allowing flowing movements that offer body and mind benefits to users [28, 33, 34].

Enabled by deep learning technology, the proposed Tai-Chi based VIGOR offers several unique advantages as an individualized, effective, sustainable, and restorative fitness modality for users with movement-based chronic health conditions. The integration of Tai-Chi with four-dimensional (4D: the sensory data includes X-Y-Z plus a somatosensory signal [35, 36]) virtual-reality technology is both innovative and feasible in that: (1) Complex human movement can be deconstructed into primitive components/modes and deep learning methods [37] can be employed to accurately formulate the spatially and temporally dependent kinetic behavior as well as reconstruct incomplete joint movement or distorted movement caused by chronic health condition(s) [38]; (2) 4D kinetic behavior can be captured and reconstructed through modern sensors, actuators, and VR/AR technologies to generate seamless human-machine interaction; (3) Despite having significant storage and computation complexity, real-time kinetic analytics is applicable over a cutting-edge big-data engine and high-performance computing platform.
