Hypometria and bradykinesia during drawing movements in individuals with Parkinson's disease.
To address the hypothesis that Parkinson's disease (PD) patients have deficits in controlling acceleration, a drawing task was used in which target size, frequency, and weight of pen were manipulated. In accordance with previous results, it was found that, relative to controls, PD patients produced movements at the required frequency, but moved significantly slower, produced less acceleration, and drew smaller-than-required stroke sizes. This resulted in smaller-than-required movement amplitudes, suggesting that hypometria and bradykinesia in drawing and/or handwriting are related. Patients were found to perform similarly to controls when the target size was 1 cm. However, their performance became more dissimilar at greater stroke lengths. In addition to the aforementioned effects it was found that movement amplitude error was less when the pen was 20 times heavier than the normal pen and that the increased load may dampen abnormal limb-stiffness characteristics induced by PD.
Broderick
Michael P
MP
Motor Control Laboratory, Department of Kinesiology, Arizona State University, P.O. Box 870404, Tempe, AZ, 85287-0404, USA. Broderick@nhrc.navy.mil
Van Gemmert
Arend W A
AW
Shill
Holly A
HA
Stelmach
George E
GE
D000368:Aged; D000369:Aged, 80 and over; D001132:Arm / Q000294:innervation / Q000503:physiopathology; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006801:Humans; D018476:Hypokinesia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D009069:Movement Disorders / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D009122:Muscle Hypertonia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D009127:Muscle Rigidity / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology*