The effect of quadriceps femoris muscle strengthening exercises on spasticity in children with cerebral palsy.

BACKGROUND AND PURPOSE: The Bobath neurodevelopmental treatment approach advised against the use of resistive exercise, as proponents felt that increased effort would increase spasticity. The purpose of this study was to test the premise that the performance of exercises with maximum efforts will increase spasticity in people with cerebral palsy (CP). Spasticity, in the present study, was defined as a velocity-dependent hyperexcitability of the muscle stretch reflex. SUBJECTS: Twenty-four subjects with the spastic diplegic form of CP (mean age=11.4 years, SD=3.0, range=7-17) and 12 subjects without known neurological impairments (mean age=11.6 years, SD=3.5, range=7-17) were assessed. METHODS: Knee muscle spasticity was assessed bilaterally using the pendulum test to elicit a stretch reflex immediately before and after 3 different forms of right quadriceps femoris muscle exercise (isometric, isotonic, and isokinetic) during a single bout of exercise training. Pendulum test outcome measures were: (1) first swing excursion, (2) number of lower leg oscillations, and (3) duration of the oscillations. RESULTS: There were no changes in spasticity following exercise between the 2 groups of subjects. DISCUSSION AND CONCLUSION: These results do not support the premise that exercises with maximum efforts increase spasticity in people with CP.

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 participants with CP were classified into three groups, with normal (mean age 15.9 years), mild/moderate (13.0 years), or severe (23.0 years) muscle tone, as assessed 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/difference between the starting and resting angles). Data were assessed using one-way analysis of variance. Outcome measures 1 to 3 differed significantly between control participants and participants with CP (p<0.05). The first swing excursion was the best predictor of the degree of spasticity in persons with CP, being significantly different between all groups (p<0.05). The number of oscillations and their duration differentiated between control participants and all participants with CP (p<0.05) but not between participants with CP who had mild/moderate versus severe spasticity (p>0.05). The relaxation index was not a sensitive measure (p>0.05 between most study groups). We conclude that the pendulum test is a valid tool for assessing spasticity in persons with CP and that the first swing excursion is the most sensitive outcome measure.