Purpose: Older adults and individuals with Parkinson’s disease exhibit impaired gait initiation performance with less effective anticipatory postural adjustments (APA) and less dynamic stepping characteristics. These observations may reflect impaired interactions between the postural and locomotor components of this task. The purpose of this study was to evaluate the effectiveness of altering the stance position of the initial swing limb on improving APA characteristics and stepping performance.
Methods: Three groups (healthy young adults, individuals with Parkinson’s disease, and age-matched older adults) of 12 participants initiated gait from three initial stance conditions: normal, backward displaced swing limb, and forward displaced swing limb. Ground reaction forces and whole body kinematics were recorded to characterize the APA and step parameters.
Results: Initiating gait from the back condition produced more forceful weight shifting (P < 0.001), greater propulsive forces (P < 0.001), and faster center-of-mass velocities throughout the stepping phases (P < 0.05).
Conclusions: Translating the swing limb 0.5-ft-length backward seems to enhance the interaction between posture and locomotion, which may have therapeutic potential for improving gait initiation performance.
1Department of Applied Physiology and Kinesiology, Center for Exercise Science, University of Florida, Gainesville, FL; 2Department of Physical Therapy, University of Florida, Gainesville, FL; and 3University of Florida Movement Disorders Center, McKnight Brain Institute, University of Florida, Gainesville, FL
Address for correspondence: Chris J. Hass, Ph.D., Department of Applied Physiology, University of Florida, Box 118205, Gainesville, FL 32611-8205; E-mail: firstname.lastname@example.org.
Submitted for publication August 2010.
Accepted for publication May 2011.