Sensitivity of the pendulum test for assessing spasticity in persons with cerebral palsy

The sensitivity of the pendulum test to variation in spasticity in persons with spastic cerebral Palsy (CP) was tested in 30 participants with CP and 10 participants without CP (controls) (mean age 13.8 years). The participan ts with CP were classified into three groups, with normal (mean age 15.9 ye ars), mild/moderate (13.0 years), or severe (23.0 years) muscle tone, as as sessed clinically using a modified Ashworth scale. Joint motion during the pendulum test was measured with an electrogoniometer. Muscle relaxation was confirmed using surface EMG, Outcome measures from the pendulum test were (1) number of oscillations, (2) duration of oscillations, (3) excursion of the first backward swing, and (4) relaxation index (first swing excursion/d ifference between the starting and resting angles), Data were assessed usin g one-way analysis of variance, Outcome measures 1 to 3 differed significan tly between control participants and participants with GP (p<0.05), The fir st swing excursion was the best predictor of the degree of spasticity in pe rsons with CP, being significantly different between all groups (p<0.05). T he number of oscillations and their duration differentiated between control participants and all participants with CP (p<0.05) but not between partici pants with Or who had mild/moderate versus severe spasticity (p>0.05). The relaxation index was not a sensitive measure (p>0.05 between most study gro ups), We conclude that the pendulum test is a valid tool for assessing spas ticity in persons with CP and that the first swing excursion is the most se nsitive outcome measure.