Researchers in Sweden used 3-D technology similar to that used to create animated motion capture in film to assess everyday upper extremity movement in stroke patients.
The researchers sought to analyze three-dimensional movement to evaluate the validity of the kinematic measures in relation to impairments and activity limitations in patients who have motor deficits resulting from stroke.
“Computer technology provides better and more objective documentation of the problem in terms of the everyday life of the patient than what human observation can provide,” Margit Alt Murphy, a doctoral candidate at the Institute of Neuroscience and Physiology in the department of clinical neuroscience and rehabilitation at the Sahlgrenska Academy at the University of Gothenburg Goteborg, Sweden, stated in a press release. “With 3-D 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.”
Researchers developed a standardized test protocol for a drinking task and examined its consistency among 29 healthy individuals and 82 individuals who had had a stroke. Using a five-camera optoelectronic motion capture system with markers placed on the participants’ upper body, trunk and head, researchers measured both temporal and spatial kinematic characteristics of movement performance. Clinical outcomes included Fugl-Meyer Assessment for Upper Extremity, Action Research Arm Test and ABILHAND.
Study results showed a good consistency in test-retest with the drinking task. Movement time, movement smoothness, angular velocity of the elbow and compensatory trunk displacement were shown to be most effective in discriminating among participants with moderate or mild impairment level after stroke and healthy participants.
Researchers also found movement smoothness, movement time and trunk displacements were strongly associated with upper extremity activity capacity level after stroke, and were responsive for capturing improvements in upper extremity activity during the first 3 months post-stroke.
“With 3-D 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 gives us a measurement for the motion that we can compare with an optimal arm motion in a healthy person,” Murphy stated. “Our study shows that the time it takes to perform an activity is strongly related to the motion quality. Even if this technology is not available, we can still obtain very valuable information about the stroke patient’s mobility by timing a highly standardized activity, and every therapist keeps a stopwatch in their pocket.”
For more information:
Murphy MA. Development and validation of upper extremity kinematic movement analysis for people with stroke. Available at https://gupea.ub.gu.se/handle/2077/33117. Accessed December 23, 2013.
Disclosure: Murphy has no relevant financial disclosures.