Robotic Therapy Helps Restore Hand Use After Stroke
A robotic therapy device may help people regain strength and normal
use of affected hands long after a stroke, according to a University of
California, Irvine study.
Stroke patients with impaired hand use reported improved ability to
grasp and release objects after therapy sessions using the Hand-Wrist
Assisting Robotic Device (HOWARD). Each patient had at least moderate
residual weakness and reduced function of the right hand, although the
affected hands were neither totally paralyzed nor unable to feel. Seven
women and six men who had suffered a stroke at least three months prior
participated in the pilot study using this robotic device.
"Most spontaneous improvement in function occurs in the first three
months after a stroke, and after that things tend to plateau," said Dr.
Steven C. Cramer, senior author of the study and associate professor in
neurology, anatomy and neurobiology at UCI. "Robot-assisted therapy may
help rewire the brain and make weak limbs move better long afterwards."
Previously, robotic devices have improved post-stroke shoulder and leg
function. Cramer said this study is one of the first attempts to
specifically aid hand function. Cramer presented HOWARD study findings
at the American Stroke Association's International Stroke Conference
2007 in San Francisco.
Developed by UCI researchers, HOWARD aids patients as they grasp and
release common objects. The robotic device wraps around the hand and
couples with a computer program that directs patients though a physical
therapy program. HOWARD users initiate hand motion, with the robot
monitoring and assisting the activity in order to meet therapeutic
goals.
"The HOWARD therapy isn't passive; the patient has to jumpstart the
program and initiate the motor command," Cramer said. "But if the hand
is weak and can only budge one-tenth of an inch, the robot helps to
complete the task so the brain relearns what it's like to make the full
movement."
In the UCI study, each patient, average age 63, received 15 two-hour
therapy sessions, spread over three weeks, designed to improve their
ability to grasp and release objects. All worked with HOWARD for the 15
sessions. For seven patients, HOWARD shaped and helped complete
movements across all sessions, while six had complete support from
HOWARD for only the second half of the sessions.
At the end of three weeks, all patients had improved in their ability
to grasp and release objects. Their average score on an Action Research
Arm Test -- which measures the ability to perform such real-world tasks
as grasping a block, gripping a drinking glass, pinching to pick up a
small marble or ball bearing, and putting your hand on your head --
improved by nearly 10 percent. And their average score rose by nearly
20 percent on the Box-and-Blocks Test, which assesses manual dexterity
as one moves blocks from one side of a box to another in one minute.
The patients also developed a 17 percent greater range of motion in
their hands and wrists and were rated as less disabled on a standard
occupational therapy assessment tool called the Fugl-Meyer score.
"Assessing changes in before-and-after scores within each subject,
these were highly significant gains after three weeks of therapy,"
Cramer said.
The UCI team is now using what they learned from study participants to
create a "son of HOWARD," with improved hand-robot connections and more
software options to individualize therapy and keep patients interested.
Stroke is a major cause of long-term disability in the United States.
More than 700,000 Americans suffer strokes annually. Stroke is the
third leading cause of death in the country. And stroke causes more
serious long-term disabilities than any other disease. Nearly
three-quarters of all strokes occur in people over the age of 65 and
the risk of having a stroke more than doubles each decade after the age
of 55, according to the National Institute of Neurological Disorders
and Stroke.
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Lucy Der-Yeghiaian, Jill See, Vu Le and Craig D. Takahashi are
co-authors of the study, which was partly funded by a National
Institutes of Health Institutional Training Grant.
About the University of California, Irvine: The University of
California, Irvine is a top-ranked university dedicated to research,
scholarship and community service. Founded in 1965, UCI is among the
fastest-growing University of California campuses, with more than
25,000 undergraduate and graduate students and about 1,400 faculty
members. The second-largest employer in dynamic Orange County, UCI
contributes an annual economic impact of $3.7 billion.
Contact: Tom Vasich
University of California - Irvine
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