Biomedical Engineering Reference
In-Depth Information
Chapter Two
A Wearable Exoskeletal Rehabilitation
Robot for Interactive Therapy
Sivakumar Balasubramanian and Jiping He
School of Biological and Health Systems Engineering, Arizona State University, Tempe,
Arizona 85287-9309, USA
2.1 INTRODUCTION
One of the important requirements for achieving functional independence in day-
to-day life is one's ability to use his/her upper-extremity (UE) dexterously. The
upper-extremity plays a crucial role in our ability to interact with our environment,
and also in performing other less obvious functions such as balance, protection
against a fall etc. Given the importance of the UE in our daily life, any interruption
of its normal motor control can possibly result in functional motor deficits of the
UE. Central nervous system (CNS) lesion caused by stroke is one of the common
conditions that interrupts normal motor control. Since, currently there is no cure
for conditions such as stroke, rehabilitation therapy is a crucial step in the process
of recovering lost motor abilities, at least partially if not fully.
Traditional rehabilitation techniques are strongly based on the neurophysio-
logical studies carried by Sherrington early in the 20
th
century. These traditional
techniques, that include the works of Bobath, Brunnstrom, Kabat andmany others,
are referred to as neurophysiologic approaches. These techniques place a lot
of emphasis on reflexes, joint synergies, and the modulation of sensory input
to the CNS. These approaches rely on utilizing sensory stimuli and reflexes to
facilitate/inhibit muscle tone and movement patterns, and quite often focus on
individual muscles or sensory pathways. Although the neurophysiologic methods
have been around for a long time and have received considerable attention,
their effectiveness has been controversial. One of the major shortcomings of
the neurophysiologic approach is the lack of carry over into functional activities
(Carr (1987)). Also, controlled studies comparing the different neurophysiologic
