Hui Ing Ma

Effect of one single auditory cue on movement kinematics in patients with Parkinson's disease.

Ma HI, Trombly CA, Wagenaar RC, Tickle-Degnen L: Effect of one single auditory cue on movement kinematics in patients with Parkinson’s disease. Am J Phys Med Rehabil 2004;83:530–536. Objective:The purpose of this study was to determine whether one single auditory cue affected movement kinematics of more than one step in a sequential upper limb task in patients with Parkinson’s disease. Design:A counter-balanced repeated-measures design was employed. A total of 16 male patients with Parkinson’s disease and 16 age-matched male and female controls performed the task under two conditions. In the signal-present condition, the participants were instructed to start the movement when they heard a bell ring. In the signal-absent condition, there was no bell ringing, and they were told to start the movement when they were ready. Kinematic performances for the first two movement segments (i.e., reaching for the pen and bringing the pen to the paper) were compared between conditions. Results:The results indicated that the presence of the single auditory cue affected movement kinematics of the patients with Parkinson’s disease but not that of the controls. When given external cueing, the patients elicited faster, more forceful, more efficient, more stable, but less smooth movement. Conclusions:The results suggest that therapists should provide external cues according to their treatment goals. In addition, researchers should be aware of the influence of start signals when designing subsequent experiments.

Effects of virtual reality training on functional reaching movements in people with Parkinson’s disease: a randomized controlled pilot trial

Objective: To investigate whether practising reaching for virtual moving targets would improve motor performance in people with Parkinson’s disease. Design: Randomized pretest–posttest control group design. Setting: A virtual reality laboratory in a university setting. Participants: Thirty-three adults with Parkinson’s disease. Interventions: The virtual reality training required 60 trials of reaching for fast-moving virtual balls with the dominant hand. The control group had 60 practice trials turning pegs with their non-dominant hand. Main outcome measures: Pretest and posttest required reaching with the dominant hand to grasp real stationary balls and balls moving at different speeds down a ramp. Success rates and kinematic data (movement time, peak velocity and percentage of movement time for acceleration phase) from pretest and posttest were recorded to determine the immediate transfer effects. Results: Compared with the control group, the virtual reality training group became faster (F = 9.08, P = 0.005) and more forceful (F = 9.36, P = 0.005) when reaching for real stationary balls. However, there was no significant difference in success rate or movement kinematics between the two groups when reaching for real moving balls. Conclusion: A short virtual reality training programme improved the movement speed of discrete aiming tasks when participants reached for real stationary objects. However, the transfer effect was minimal when reaching for real moving objects.

Physical Activity Patterns and Quality of Life of Overweight Boys: A Preliminary Study

Objective We compared the physical activity (PA) patterns and the quality of life (QoL) between overweight and normal-weight boys, and examined the relationship between PA and QoL of overweight boys. Methods Eighteen overweight boys (age range: 8–10 years, mean ± standard deviation: 9.36 ± 0.82 years) and 18 age-matched, normal-weight counterparts (age range: 8–10 years, mean ± standard deviation: 9.01 ± 0.65 years) participated in this study. All participants were in the 3rd or 4th grade. Each boy completed a QoL questionnaire and wore an accelerometer on his waist for a week to measure his PA during that period. Independent t tests were used to examine the differences in QoL and PA between the overweight and normal-weight boys. Paired t tests were used to test the differences in PA between weekdays and weekend days for each group. Finally, Pearson correlations were used to analyze the relationships between PA and QoL in overweight boys. Results Overweight boys reported a significantly lower QoL, and participated in significantly less PA on weekends than did normal-weight boys. A moderate and marginally significant correlation was found between PA on weekends and QoL in overweight boys. Conclusion Our findings suggest the importance of increasing weekend PA for overweight boys. Occupational therapists should encourage overweight boys to engage in PA that the boys are interested in on weekends, and conduct a PA program for overweight boys.

Comparison of Virtual Reality Versus Physical Reality on Movement Characteristics of Persons With Parkinson's Disease: Effects of Moving Targets

OBJECTIVE To compare the performance of reaching for stationary and moving targets in virtual reality (VR) and physical reality in persons with Parkinsons disease (PD). DESIGN A repeated-measures design in which all participants reached in physical reality and VR under 5 conditions: 1 stationary ball condition and 4 conditions with the ball moving at different speeds. SETTING University research laboratory. PARTICIPANTS Persons with idiopathic PD (n=29) and age-matched controls (n=25). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Success rates and kinematics of arm movement (movement time, amplitude of peak velocity, and percentage of movement time for acceleration phase). RESULTS In both VR and physical reality, the PD group had longer movement time (P<.001) and lower peak velocity (P<.001) than the controls when reaching for stationary balls. When moving targets were provided, the PD group improved more than the controls did in movement time (P<.001) and peak velocity (P<.001), and reached a performance level similar to that of the controls. Except for the fastest moving ball condition (0.5-s target viewing time), which elicited worse performance in VR than in physical reality, most cueing conditions in VR elicited performance generally similar to those in physical reality. CONCLUSIONS Although slower than the controls when reaching for stationary balls, persons with PD increased movement speed in response to fast moving balls in both VR and physical reality. This suggests that with an appropriate choice of cueing speed, VR is a promising tool for providing visual motion stimuli to improve movement speed in persons with PD. More research on the long-term effect of this type of VR training program is needed.

Reliability and validity testing of a Chinese-translated version of the 39-item Parkinson's Disease Questionnaire (PDQ-39).

The trend toward international cooperation in research projects emphasizes the need to translate existing validated tools into local languages. The purpose of this study was to test the reliability and validity of a Chinese-translated version of the 39-item Parkinson’s Disease Questionnaire (PDQ-39). Seventy-three Taiwanese individuals with Parkinson’s disease were consecutively recruited. The internal consistency reliability was satisfactory for all domains (Cronbach’s α=0.80–0.96), except for the social support, cognition, and bodily discomfort domains (α=0.58–0.63). The convergent validity was also supported by strong correlations between domains measuring related constructs of the PDQ-39 and Unified Parkinson’s Disease Rating Scale (r=0.81–0.86), and between those of the PDQ-39 and SF-36 (r=−0.70–−0.93). Except for the bodily discomfort domain, all domains of the PDQ-39 significantly discriminated patients at different stages, as indicated by the Hoehn and Yahr scale. Overall, the results of this study are consistent with the reports of the PDQ-39 in other countries (e.g., UK, Spain, US, and Greece), which suggests that the PDQ-39 is appropriate for use among Taiwanese individuals with PD. This study lays the foundation for future combinations and comparisons of data cross-nationally.

The effects of two different auditory stimuli on functional arm movement in persons with Parkinson's disease: a dual-task paradigm

Objective: To examine, in a dual-task paradigm, the effect of auditory stimuli on people with Parkinsons disease. Design: A counterbalanced repeated-measures design. Setting: A motor control laboratory in a university setting. Subjects: Twenty individuals with Parkinsons disease. Experimental conditions: Each participant did two experiments (marching music experiment and weather forecast experiment). In each experiment, the participant performed an upper extremity functional task as the primary task and listened to an auditory stimulus (marching music or weather forecast) as the concurrent task. Each experiment had three conditions: listening to the auditory stimulus, ignoring the auditory stimulus and no auditory stimulus. Main measures: Kinematic variables of arm movement, including movement time, peak velocity, deceleration time and number of movement units. Results: We found that performances of the participants were similar across the three conditions for the marching music experiment, but were significantly different for the weather forecast experiment. The comparison of condition effects between the two experiments indicated that the effect of weather forecast was (marginally) significantly greater than that of marching music. Conclusions: The results suggest that the type of auditory stimulus is important to the degree of interference with upper extremity performance in people with Parkinsons disease. Auditory stimuli that require semantic processing (e.g. weather forecast) may distract attention from the primary task, and thus cause a decline in performance.

Increasing speed to improve arm movement and standing postural control in Parkinson's disease patients when catching virtual moving balls.

Research has shown that moving targets help Parkinsons disease (PD) patients improve their arm movement while sitting. We examined whether increasing the speed of a moving ball would also improve standing postural control in PD patients during a virtual reality (VR) ball-catching task. Twenty-one PD patients and 21 controls bilaterally reached to catch slow-moving and then fast-moving virtual balls while standing. A projection-based VR system connected to a motion-tracking system and a force platform was used. Dependent measures included the kinematics of arm movement (movement time, peak velocity), duration of anticipatory postural adjustments (APA), and center of pressure (COP) movement (movement time, maximum amplitude, and average velocity). When catching a fast ball, both PD and control groups made arm movements with shorter movement time and higher peak velocity, longer APA, as well as COP movements with shorter movement time and smaller amplitude than when catching a slow ball. The change in performance from slow- to fast-ball conditions was not different between the PD and control groups. The results suggest that raising the speed of virtual moving targets should increase the speed of arm and COP movements for PD patients. Therapists, however, should also be aware that a fast virtual moving target causes the patient to confine the COP excursion to a smaller amplitude. Future research should examine the effect of other task parameters (e.g., target distance, direction) on COP movement and examine the long-term effect of VR training.

Everyday memory in children with developmental coordination disorder

Children with developmental coordination disorder (DCD) have deficits in working memory, but little is known about the everyday memory of these children in real-life situations. We investigated the everyday memory function in children with DCD, and explored the specific profile of everyday memory across different domains. Nineteen children with DCD and 19 typically developing (TD) children participated in the study. Their everyday memory performance was evaluated using the Rivermead Behavioral Memory Test for Children, which showed that 52.6% of the children with DCD had everyday memory deficits. The overall everyday memory scores of the DCD group were significantly lower than those of the controls, particularly in the verbal and visual memory domains. Pearson correlation analysis indicated significant associations between verbal intelligence and memory scores. Analysis of covariance with verbal intelligence as a covariate showed no significant differences between groups in memory scores. Mediator analysis supported the notion that everyday memory deficits in children with DCD were fully mediated through verbal intelligence. We provide evidence of everyday memory deficits in most of the children with DCD, and hypothesize that language abilities are their underlying cause. The clinical implications of these findings and recommendations for additional research are discussed.

Trunk–arm coordination in reaching for moving targets in people with Parkinson’s disease: Comparison between virtual and physical reality

We used a trunk-assisted prehension task to examine the effect of task (reaching for stationary vs. moving targets) and environmental constraints (virtual reality [VR] vs. physical reality) on the temporal control of trunk and arm motions in people with Parkinsons disease (PD). Twenty-four participants with PD and 24 age-matched controls reached for and grasped a ball that was either stationary or moving along a ramp 120% of arm length away. In a similar VR task, participants reached for a virtual ball that was either stationary or moving. Movement speed was measured as trunk and arm movement times (MTs); trunk-arm coordination was measured as onset interval and offset interval between trunk and arm motions, as well as a summarized index-desynchrony score. In both VR and physical reality, the PD group had longer trunk and arm MTs than the control group when reaching for stationary balls (p<.001). When reaching for moving balls in VR and physical reality, however, the PD group had lower trunk and arm MTs, onset intervals, and desynchrony scores (p<.001). For the PD group, VR induced shorter trunk MTs, shorter offset intervals, and lower desynchrony scores than did physical reality when reaching for moving balls (p<.001). These findings suggest that using real moving targets in trunk-assisted prehension tasks improves the speed and synchronization of trunk and arm motions in people with PD, and that using virtual moving targets may induce a movement termination strategy different from that used in physical reality.

The effect of eating utensil weight on functional arm movement in people with Parkinson’s disease: a controlled clinical trial

Objective: To investigate the effect of eating utensil weight on kinematic performance in people with Parkinson’s disease. Design: A counterbalanced repeated-measures design. Setting: A motor control laboratory in a university setting. Subjects: Eighteen adults with Parkinson’s disease and 18 age-matched controls. Experimental conditions: Each participant performed a food transfer task using spoons of three different weights: lightweight (35 g), control (85 g) and weighted (135 g). Kinematic variables of arm movement were derived and compared between conditions. Main measures: Kinematic variables of arm movement, including movement time, peak velocity and number of movement units. Results: Utensil weights significantly affected the movement kinematics of all participants. Both groups had fewer movement units in the lightweight condition (Parkinson’s disease group: 22.18, controls: 19.89) than in the weighted condition (Parkinson’s disease group: 22.68, controls: 21.36), suggesting smoother movement in the former condition. In addition, both groups had higher peak velocity in the lightweight than in the weighted condition. Conclusions: Our findings suggest that a lightweight utensil may facilitate smoother and higher-velocity arm movement than a weighted one in people with Parkinson’s disease.