SIMULTANEOUS ASHWORTH MEASUREMENTS AND ELECTROMYOGRAPHIC RECORDINGS IN TETRAPLEGIC PATIENTS

Objective: A recent prevalence study of 353 spinal cord injured (SCI) individuals in the greater Stockholm area showed problematic spasticit y in 30% of this population. To treat spasticity, the evaluation becom es crucial. The modified Ashworth scale (MAS) is the clinically most-u sed scale to grade degree of spasticity. This study evaluated whether the MAS correlated with electromyographic (EMC) recordings of muscle a ctivity. Study Design: This cross-sectional study was performed at an outpatient clinic that has the responsibility to do a standardized, ye arly follow-up of all SCI patients in the greater Stockholm area. Thir ty-eight SCI individuals met the inclusion criteria; 15 of the 38 were randomly selected for the study. They were all motor-complete tetrapl egic men; mean age was 33 years and mean time since injury was 9 years . Spasticity evaluation was performed by flexing and extending the kne es during simultaneous EMG recordings and MAS assessment of the thigh muscle activity. Results: Eighty percent of the individual EMG recordi ngs correlated significantly with the corresponding Ashworth measureme nts. The spastic resistance, as measured both clinically and electromy ographically, was Stronger and lasted longer during extension than fle xion movements. Spearman coefficients for correlation of quantitative spasticity measures with MAS grades were calculated. EMG and clinical measures of spasticity were more closely correlated for flexion moveme nts. Among EMG parameters, duration of movement-associated electrical activity invariably correlated significantly with the MAS grades (p <. 05). Furthermore, Ashworth measurements of movement-associated spastic ity showed a positive correlation with the EMG parameters mean, peak, and start to peak of electrical activity. Each increasing grade on the MAS corresponded to increasing myoelectric activity levels for each m ovement. Conclusion: EMG parameters were significantly positively corr elated with simultaneous MAS measurements of the spastic muscle contra ction. The Ashworth scale may therefore accurately reflect the movemen t-provoked spasticity in motor-complete tetraplegic patients. (C) 1998 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.