Abstract
A paucity of objective outcome measures exists for managing movement disorders, including degenerative Lumbar Spinal Stenosis (LSS). Application of Fitts' Law may provide a novel approach to clinical outcome measurement because task performance is resistant to learning and a range of performance ability can be measured by altering task difficulty. The present study compared LSS patients (N=9) to healthy age matched participants (N=7) on a lower limb aiming task to determine their respective motor performance characteristics. Participants performed pointing movements with their great toe to a series of squares that appeared on a touch screen monitor with 6 possible indices of difficulty (ID; 3 target distances and 2 target widths). Movements were recorded using an Optotrak 3D Investigator (300Hz). Reaction time (RT), movement time (MT) and peak velocity (PV) were analyzed using 2 Group (Healthy, LSS) by 6 ID (2, 3a, 3b, 4a, 4b, 5) mixed ANOVAs. A main effect for MT demonstrated a linear relationship with ID indicating Fitts' law was maintained. Overall, LSS patients demonstrated significantly faster RTs and slower MTs. A Group x ID interaction for PV revealed LSS patients did not scale movement execution to the same degree as healthy controls. Findings are discussed as they relate to Fitts' Law interpretation and clinical application. Future research will aid clinical incorporation ofmotor performance tasks as tools to establish functional ability.Acknowledgments: Direct support for this research was provided by the Alexander Gibson Fund, additional support provided by the Manitoba Health Research Council.