Assessment of Upper Limb Spasticity after Stroke: Characterizing Resistance to Passive Stretch and the Impact on Active Control

Spasticity is a common phenomenon following stroke, characterized by involuntary resistance to passive stretch. Clinical assessments of spasticity are challenged as having poor sensitivity and do not describe the impact of spasticity on function. The purpose of this thesis was to objectively measure spasticity and establish the impact of spasticity on active, functional movement. Two studies were undertaken to A) assess kinematic variables that characterize spasticity during passive stretch and B) identify components of active, functional movement impacted by spasticity. Findings for Study 1 revealed that individuals with spasticity exhibit a measurable catch and release at fast velocities of stretch and increased resistance to passive movement at slow velocities. Findings for Study 2 revealed that stability during reaching and use of the more affected side were impacted by spasticity. This work provides a foundation for the development of a clinical assessment of spasticity that includes both passive and active components.M.Sc