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Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity
Published on: June 12, 2019
Spasticity measurement based on tonic stretch reflex threshold in stroke using a portable device.
Andra Calota1, Anatol G Feldman, Mindy F Levin
1School of Physical and Occupational Therapy, McGill University, 3654 Promenade Sir William Osler, Montreal, Que., Canada H3G 1Y5.
Summary
The tonic stretch reflex threshold (TSRT) shows moderate reliability for quantifying spasticity in stroke survivors. This measure did not correlate with resistance to stretch, suggesting it may be a better indicator for moderate to severe spasticity.
Area of Science:
- Neurology
- Rehabilitation Medicine
- Biomedical Engineering
Background:
- Spasticity is a common motor disorder following stroke, impacting motor function and quality of life.
- Current clinical scales for spasticity assessment, like the Modified Ashworth Scale (MAS), have limitations in objectivity and sensitivity.
- The tonic stretch reflex threshold (TSRT) offers a potential objective measure of motoneuron excitability in spasticity.
Purpose of the Study:
- To assess the intra- and inter-evaluator reliability of the tonic stretch reflex threshold (TSRT) for quantifying spasticity.
- To investigate the correlation between TSRT and resistance to stretch as measured by the Modified Ashworth Scale (MAS).
Main Methods:
- Spasticity was evaluated in 20 chronic stroke survivors using a portable device and MAS.
- Evaluations were conducted over two days by three independent evaluators.
- Electromyography (EMG) and elbow displacement were recorded during controlled elbow stretches at various velocities to determine TSRT.
Main Results:
- Intra-evaluator reliability for TSRT ranged from 0.46 to 0.68, and inter-evaluator reliability ranged from 0.53 to 0.68, indicating moderate to good consistency.
- The TSRT measure of spasticity did not show a significant correlation with the MAS scores for resistance to stretch.
- Reliability was notably better in subjects with moderate to high spasticity.
Conclusions:
- TSRT demonstrates moderate reliability and may serve as a more representative measure of spasticity in individuals with moderate to severe spasticity.
- Further refinement of the portable device is recommended to accurately quantify all spasticity levels.
- TSRT presents a potential alternative clinical measure to existing spasticity assessment scales.
