Evaluation of Stretch Reflex Threshold on Stroke Patients Using the New Portable Spasticity-measuring System

J Korean Assoc EMG Electrodiagn Med 2009;11(2):85-91.
Published online December 31, 2009.

Abstract

Objective: To introduce a new hand-driven portable system for measuring the spasticity and to test theavailability of the new portable system for measuring the spasticity.
Method: Spasticity was evaluated in 15 patients with stroke using a new portable system and the ModifiedAshworth scale (MAS). The device was designed in order to measure the joint angle, angular velocity,electromyographic signals, and torque. Each sets of 10 passive elbow joint movements were completedusing a new portable system at 60, 90, 120, 150, and 180 degrees per second (deg/s) while surfaceelectromyographic data were collected from the biceps, and triceps. Velocity-dependent dynamic stretchreflex thresholds (DSRTs) were recorded. These values were used to compute tonic stretch reflex threshold(TSRT). The correlations between TSRT and the MAS were investigated.
Results: MAS grade was distributed from 1 to 2 grade (1: 40.0%, 1+: 33.3%, 2: 26.7%). TSRT, r2 valuesranged from 116.6 to 134.6 and 0.45 to 0.88, respectively. The correlation between MAS grade and TSRTwas strong correlation (rho=-0.708, p=0.003).
Conclusion: We showed that the new portable system is clinically more useful instrument, which canproduce reliable objective data and were more convenient on spasticity measurement. The new measuringsystem is a portable hand-driven spasticity-measurement system, which encompass various scopes ofspasticity-related human signals such as electrophysiologic, kinematic, and biomechanical data. We suggestthat this new system can diagnose the spasticity of the muscles, objectively.

Key Words: Spasticity, Portable system, Hemiplegic, Central nervous system, Stretch reflex