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Previous research has shown that Parkinson's-disease (PD) patients produce irregular movement paths during a rapid arm pointing task. The aim of this study was to investigate the movement paths of PD patients during a prehensile action to objects requiring different levels of precision. Thus, we sought to determine if movement-accuracy requirements affect(More)
The transport and grip components are two controlled components of a prehensile movement. These components are coordinated so that objects of varying size and shape resting in diverse locations can be grasped easily. It has been suggested that the timing between these two components is a specified parameter, although the origin of such timing is unknown.(More)
The aim of this study was to determine the effect of age on the modulation of forces produced by the digits and to determine the effects of practice on the control of these forces in young and older adults. Young (n=14, 19–28 years) and old (n=12, 67–75 years) adults used a precision grip to perform a variable force-tracking task (sine wave, 5–25% of(More)
Parkinson's disease patients and control subjects performed a simultaneous bilateral reach-to-grasp task to two different sized objects and then pulled the two objects apart. The first phase of the task (reaching-to-grasp) allowed us to examine the issue that impairments in simultaneous movements for Parkinson's disease patients are seen in some tasks but(More)
BACKGROUND Animal studies indicate forced exercise (FE) improves overall motor function in Parkinsonian rodents. Global improvements in motor function following voluntary exercise (VE) are not widely reported in human Parkinson's disease (PD) patients. OBJECTIVE The aim of this study was to compare the effects of VE and FE on PD symptoms, motor function,(More)
BACKGROUND Amisulpride is a potent substituted benzamide antipsychotic drug claimed to improve the negative symptoms of schizophrenia, particularly at low dosage. METHOD Sixty long-term in-patients with schizophrenia and selected for predominant negative symptoms were randomised to receive either haloperidol or amisulpride. Over a year there was(More)
 Arm movements in the horizontal plane consisting of two segments were examined to determine whether the difficulty of the second segment influenced the kinematic characteristics of the first segment. The direction of the first segment was an elbow extension movement away from the trunk and remained constant throughout the experiment. The direction of the(More)
Individuals with Parkinson's disease (PD) often experience cognitive declines. Although pharmacologic therapies are helpful in treating motor deficits in PD, they do not appear to be effective for cognitive complications. Acute bouts of moderate aerobic exercise have been shown to improve cognitive function in healthy adults. However, individuals with PD(More)
Deep brain stimulation (DBS) is a surgical procedure that has been shown effective in improving the cardinal motor signs of advanced Parkinson's disease, however, declines in cognitive function have been associated with bilateral subthalamic nucleus (STN) DBS. Despite the fact that most activities of daily living clearly have motor and cognitive components(More)
Many studies have examined the coordination of reach-to-grasp movements. However, there is debate regarding the mechanism of coordination between the transport and grasp components. The current study investigated the stability of temporal and spatial measures for reaches in which transport path was altered early or late in the reaching action. Transport(More)