DESIGN AND EVALUATION OF PEDIATRIC GAIT REHABILITATION ROBOTS

CHAPTER 1
INTRODUCTION
Since the dawn of humanity, walking has been an integral aspect of life. The ability to walk defines the growth of children, the strength of adults, and the decline of health in the elderly. The inability to effectively ambulate comes with a host of physical, psychological, and social implications that are detrimental to the overall well-being of a human. In short, walking is one of the major indicators of human health. 
The main purpose of perambulation is mobility. In general, mobility is defined as the capacity to move through physical space, although true mobility spans much farther than this simple definition. Schwanen and Ziegler suggest that mobility, independence, and well-being are all interdependent and complicated mechanisms that complement each other, and can’t be undervalued for their importance [1]. According to Schwanen and Ziegler,
[F]or those whose embodied capacities have diminished over time mobility, independence and wellbeing can become linked up in a downward spiral (p. 724).
The impact of mobility on physical and psychological health is profound. Immobility and reduced mobility are linked to a long list of physical health problems spanning across every major organ system [2]. Some of the complications are increased risks for blood clots, indigestion, osteoporosis, changes in hormone balance, bladder infections, pressure ulcers, atrophied muscles, difficulty expanding lungs fully, weakened coughs, and low back pain. Psychologically, immobility can cause depression, anxiety, apathy, mood swings, feelings of helplessness, loss of normal sleep cycles, and delirium. 
According to the U.S. Census, 30.6 million American adults and teenagers experience difficulty in perambulation, including walking or climbing stairs [3]. Correspondingly, about 3.6 million people use a wheelchair and 11.6 million people use another form of assistance when walking, such as a cane or walker. The census survey also asked about information on difficulty moving large objects (such as a chair), reaching the top shelf, and standing for long periods of time. The inability to effectively perambulate affects more than simply the ability to move from one location to another.
Gait therapy involves a series of guided tasks facilitated by a therapist in which an individual moves through the motions of walking, often with significant assistance. Gait therapy is useful for many purposes. For one, gait therapy can be used to teach the correct leg movements involved in walking. However, it can also be used with individuals who are unable to walk to provide them with valuable exercise to increase their health. The prevalence of individuals with gait-related disabilities and ambulatory issues adds to the need for reliable, cost-effective gait therapy treatment and exercise. 
Gait therapy is especially important for children. According to the U.S. Health and Human Services Advisory Committee, children’s muscular, skeletal, and cardiovascular health all show marked improvement with increased physical exercise [4]. Aside from physical benefits, learning how to walk is integral to the development of psychological independence. Between the ages of one and three, children begin to use their newfound walking ability as a way of expressing and exploring their own capability. Erikson [5] theorized that inhibitions in this stage, such as repression of walking capability, would tend to incur self-doubt and self-esteem problems in children that would last for years to come. 
Because of this, gait therapy is needed for children. However, many of the gait therapy methods that are used for children right now are either clinician-intensive or expensive. This is an issue when it comes to rural or smaller rehabilitation facilities, hospitals, or home health centers. As such, there exists a need for inexpensive, easy-touse, effective pediatric gait therapy equipment.
Realistically, there are no gait therapy mechanisms that accurately trace gait trajectories every cycle. However, it is currently unknown what effect gait mechanisms have on therapy as their trajectory becomes more gait-like. One of the goals of this research is to develop a gait-like machine and compare to existing rehabilitation technologies. Using the new machine, it will be possible to determine whether the cyclical, repetitive nature of current gait rehabilitation is the driving force behind gait therapy or if the therapy effectiveness is correlated to trajectory accuracy.