Abstract
While shuffling gait is typical of Parkinson's disease (PD), difficulty turning appears to be a motor impairment in some but not all patients. For example, patients who experience freezing of gait (FOG) exhibit interruptions to gait while turning. In contrast, patients with axial rigidity rotate segments simultaneously during a turn (so called "en bloc" turns). The aim of this study was to evaluate if turning deficits in patients with FOG is related to axial control (as seen in axially rigid patients). As such, 3 PD groups were evaluated: FOG (n=6), axial rigidity (AR) (n=6), and a PD control group with neither symptom (CO) (n=6). Outcome measures included: number of steps, time and cadence during the turn in 3 walking conditions: straight (0º); 90º and 180º turns. Five trials of each walking condition were completed. Turning conditions required participants to turn at the mid-point of a 6 m path towards a pre-determined eye-level target located at the end of the path. Results showed increases in the number of steps as turn angle sharpened (p<0.001). Additionally, FOG took significantly more steps than the other groups during 180º turns (p<0.001) as well as significantly more steps than CO for 90º turns (p=0.04) while completing the turn in the same amount of time. While axially rigid PD patients do not show differences in the above gait measures compared to PD controls, we can conclude that FOG deficits are not specifically related to axial rigidity.Acknowledgments: Canadian Foundation for Innovation and Sun Life Financial