Quantitative evaluation of spasticity at the elbow of stroke patients

The aim of this study was to introduce a standard objective method to assess spasticity in the elbow flexor and extensor muscles. Clinical evaluation of spasticity, commonly used by clinicians, is based on Modified Ashworth Scale (MAS). Subjective nature of this method may affect the accuracy and precision of evaluations. Hence, introducing an objective standard method based on quantitative measurements may be helpful. The passive resistant torque with respect to the elbow joint angle during passive flexion and extension imposed from 15 to 120 deg /sec with an isokinetic dynamometer was measured in 15 stroke patients with spasticity and 15 healthy subjects. To extract viscous and elastic indices of passive resistant torques of elbow flexion and extension, measures were extracted using MATLAB-R2009 software and statistic analyses were done by SPSS version 16. The relation between each computed measure and the level of spasticity were analyzed. Results showed a clear correlation between lower scores of MAS and elastic indices of passive torque; while, moderate-to-high levels of MAS were better correlated with viscous indices. Results of this research may help introduce a standard objective method for evaluation of spasticity.