Year of Publication


Document Type



Health Sciences


Rehabilitation Sciences

First Advisor

Timothy L. Uhl

Second Advisor

Gilson J. Capilouto


The stiff-knee gait pattern of children diagnosed with cerebral palsy (CP) is assumed to be caused by spasticity of the quadriceps which interferes with knee flexion normally occurring during the swing phase of walking. In current clinical practice, the ability to assess quadriceps spasticity is limited by the lack of an objective and reliable test that discriminates the role spasticity plays in functional limitations. The primary purpose of this series of studies was to assess the pendulum test as an objective measure of quadriceps spasticity. The first study assessed the reliability of the pendulum test. Moderate to very high between day reliability for all thirteen measures of the pendulum test were found. The second study assessed the discriminant ability of the pendulum test to correctly identify a stiff-knee gait pattern. Because most clinicians do not have access to a three dimensional motion analysis system, the third study assessed the reliability and accuracy of visual observation of the pendulum test. Sixty-eight children with a primary diagnosis of cerebral palsy participated. A three-dimensional motion analysis system was used to measure the subjects knee motion while walking, and performing the pendulum test. Spasticity of the quadriceps was also assessed using traditional clinical measures i.e., the modified Ashworth scale (MAS), and the Ely tests. Forty-seven percent of the variance in the stiff-knee gait pattern was explained by a regression model using the pendulum test and traditional clinical measures. The only significant measure in the regression model was the magnitude of knee motion occurring during the first swing of the pendulum test (A1). Discriminant analysis revealed the A1 measure correctly classified 77% of the subjects knee-gait pattern. Four observers demonstrated moderate accuracy and repeatability in estimating A1 value. The visual assessment of A1 correctly classified 72-76% of the subjects knee-gait pattern with no prior knowledge of the subjects gait. This series of studies demonstrated the pendulum test is an objective, repeatable measure of quadriceps spasticity. A negative pendulum test (indicated by an A1 value greater than 45 degrees) is more useful for ruling out a stiff-knee gait pattern compared to the traditional clinical measures.