In a unique study, researchers have used 3D technology from the film
and video game industry to analyse everyday movements of stroke
The results of the study indicate that computerised
motion analysis increases the knowledge of how stroke patients can
improve their ability to move through rehabilitation.
In the film
and video game industry, motion capture technology is used to convert
people's movements into computer animations - famous examples include
the character Gollum from the Lord of the Rings and Na'vi from the
blockbuster film Avatar.
Margit Alt Murphy and colleagues at the
Sahlgrenska Academy, University of Gothenburg in Sweden, have brought
the technology into the research laboratory.
motion-capture technology to film everyday movements among roughly one
hundred people, both healthy people and people who suffered a stroke.
3D animations have provided a completely new level of detail in terms
of mobility in stroke patients - knowledge that can help patients
achieve more effective rehabilitation.
provides better and more objective documentation of the problem in terms
of the everyday life of the patient than what human observation can
provide," Murphy said.
"With 3D technology, we can measure a
patient's movements in terms of numbers, which means that small changes
in the motion pattern can be detected and can be fed back to the patient
in a clear manner.
"Our results show that computerised motion
analysis could be a complement to a physician's clinical diagnosis and
an important tool in diagnosing motion problems," Murphy added.
The technology is highly advanced, but for the patient, the method is simple.
the study, the test subjects were equipped with small, round reflex
balls on their arm, trunk and head, and they were then instructed to
drink water out of a glass.
The motion is documented by high-speed
cameras whose infrared light is reflected by the balls and sent back to
the computer where they create a 3D animated image in the form of a
"With 3D animation, we can measure the joint angle,
speed and smoothness of the arm motion, as well as which compensating
motion patterns the stroke patient is using. This give us a measurement
for the motion that we can compare with an optimal arm motion in a
healthy person," said Murphy.
"Our study shows that the time it takes to perform an activity is strongly related to the motion quality.
if this technology is not available, we can still obtain very valuable
information about the stroke patient's mobility by timing a highly
standardised activity, and every therapist keeps a stopwatch in their
pocket," said Murphy.