Laurie Wishart

Bimanual coordination deficits with Parkinson's disease: The influence of movement speed and external cueing

Continuous coordinated movement of the upper limbs performed at different movement frequencies, and with different external timing conditions, was examined in individuals with Parkinsons disease (PD) and healthy, age‐ and gender‐matched controls. Participants performed symmetric in‐phase movements toward and away from the midline of the body, and isodirectional anti‐phase movements at one of three metronome speeds (0.75, 1.25, and 1.75 Hz), and in two different auditory cueing conditions (cue present, cue absent). Measures of relative phase accuracy (absolute mean error) and stability (standard deviation) revealed that individuals with PD performed in‐phase movements as well as the controls, while anti‐phase movements were performed with greater mean error and variability. The adverse effects of PD on the anti‐phase task were also reflected by freezing (8.1% of anti‐phase trials) and hypometric deficits (5.1% of anti‐phase trials) during movement. None of these PD‐related impairments occurred during in‐phase trials. The overall accuracy or stability of movement coordination was not improved with the presence of external pacing cues, suggesting that although execution impairments of individuals with PD may be dramatically influenced by attention, external cueing does not necessarily improve movement performance.

Age-related differences and the role of augmented visual feedback in learning a bimanual coordination pattern

The purpose of this study was to investigate the effects of aging and the role of augmented visual information in the acquisition of a new bimanual coordination pattern, namely a 90 degrees relative phase pattern. In a pilot study, younger and older adults received augmented visual feedback in the form of a real-time orthogonal display of both limb movements after every fifth trial. Younger adults acquired this task over three days of practice and retained the task well over periods of one week and one month of no practice while the older adults showed no improvement at all on the task. It was hypothesized that the amount of augmented information was not sufficient for the older adults to overcome the strong tendency to perform natural, intrinsically stable coordination patterns, which consequently prevented them from learning the task. The present study evaluated the age-related role of augmented visual feedback for learning the new pattern. Participants were randomly assigned within age groups to receive either concurrent or terminal visual feedback after every trial in acquisition. In contrast to the pilot study, all of the older adults learned the pattern, although not to the same level as the younger adults. Both younger and older adults benefitted from concurrent visual feedback, but the older adults gained more from the concurrent feedback than the younger adults, relative to terminal feedback conditions. The results suggest that when learning bimanual coordination patterns, older adults are more sensitive to the structure of the practice conditions, particularly the availability of concurrent visual information. This greater sensitivity to the learning environment may reflect a diminished capacity for inhibitory control and a decreased ability to focus attention on the salient aspects of learning the task.

EFFECTS OF AGING AND REDUCED RELATIVE FREQUENCY OF KNOWLEDGE OF RESULTS ON LEARNING A MOTOR SKILL

Although there is evidence for age-related changes in both cognition and motor control, very little is known about the effect of age on learning of new motor skills. The present experiment addressed the interaction between aging and the role of knowledge of results (KR) on a motor learning task. Using a three-segment task on which each segment had specific timing goals, three different manipulations of relative frequency of information about performance were compared in younger and older adults. The three conditions were (a) 100% KR in which information about performance on each segment was provided after every trial, (b) 67% KR in which the performance information was faded over trials, and (c) 67% KR in which the performance information was faded over the segments within each trial. Following 90 acquisition trials, all subjects performed retention, transfer, and reacquisition tests. There were age-related differences for movement accuracy and consistency on acquisition and on the retention tests but not on the transfer test. However, none of these differences interacted with the frequency of KR manipulations. Surprisingly, there was no effect due to the fading schedules of KR. In general, these results indicated that younger and older adults use KR in a similar way to learn a motor skill.

Disruptive influences of a cued voluntary shift on coordinated movement in Parkinson’s disease

A temporary and/or involuntary stoppage of movement is identifiable in the execution phase of writing, walking, and turning movements in individuals with Parkinsons disease (PD) and may be referred to as freezing. However, the unpredictability of such akinetic impairments has made it difficult to study experimentally. The present study compared PD and age-matched control groups in their ability to coordinate continuous and simultaneous upper limb movements in trials involving two parts. In the first part of each trial, participants performed either in-phase movements (symmetric, simultaneous movement toward and away from the midline of the body), or anti-phase movements (isodirectional). At the midpoint of the trial, they were signaled by an auditory metronome to execute an intentional and voluntarily switch from the coordination currently being performed to the opposite coordination pattern. In the second half of the trial participants were required to maintain performance in the other coordination mode. All trials were paced by an auditory metronome at one of three different speeds (0.75, 1.25, 1.75 Hz). Measures of temporal coordination (relative phase) indicated that overall, participants with PD required significantly longer periods of time to achieve a switch between coordination patterns compared to healthy controls, and experienced greater difficulty changing from the in-phase to anti-phase mode of coordination. As well, movement stoppage was observed in 53.9% of the in-phase to anti-phase switch trials, but in only 15.5% of the anti-phase to in-phase trials. We conclude that interruptions to movement execution are most common when switching to coordinated movements that impose greater motor demands in individuals with PD.

The physical environment as a fall risk factor in older adults: Systematic review and meta‐analysis of cross‐sectional and cohort studies

BACKGROUND/AIM Evidence that the physical environment is a fall risk factor in older adults is inconsistent. The study evaluated and summarised evidence of the physical environment as a fall risk factor. METHODS Eight databases (1985-2006) were searched. Investigators evaluated quality of two categories (cross-sectional and cohort) of studies, extracted and analysed data. RESULTS Cross-sectional: falls occur in a variety of environments; gait aids were present in approximately 30% of falls. COHORT Home hazards increased fall risk (odds ratio (OR) = 1.15; 95% confidence interval (CI): 0.97-1.36) although not significantly. When only the high quality studies were included, the OR = 1.38 (95% CI: 1.03-1.87), which was statistically significant. Use of mobility aids significantly increased fall risk in community (OR = 2.07; 95% CI: 1.59-2.71) and institutional (OR = 1.77; 95% CI: 1.66-1.89) settings. CONCLUSIONS Home hazards appear to be a significant risk factor in older community-dwelling adults, although they may present the greatest risk for persons who fall repeatedly. Future research should examine relationships between mobility impairments, use of mobility aids and falls.

Self-management interventions for chronic disease: a systematic scoping review

Objective: To investigate the contributions of physiotherapy and occupational therapy to self-management interventions and the theoretical models used to support these interventions in chronic disease. Data sources: We conducted two literature searches to identify studies that evaluated self-management interventions involving physiotherapists and occupational therapists in MEDLINE, the Cochrane Library, CINAHL, EMBASE, AMED (Allied and Complementary Medicine), SPORTdiscus, and REHABDATA databases. Study selection: Four investigator pairs screened article title and abstract, then full text with inclusion criteria. Selected articles (n = 57) included adults who received a chronic disease self-management intervention, developed or delivered by a physiotherapist and/or an occupational therapist compared with a control group. Data extraction: Four pairs of investigators performed independent reviews of each article and data extraction included: (a) participant characteristics, (b) the self-management intervention, (c) the comparison intervention, (d) outcome measures, construct measured and results. Data synthesis: A total of 47 articles reported the involvement of physiotherapy in self-management compared with 10 occupational therapy articles. The type of chronic condition produced different yields: arthritis n = 21 articles; chronic obstructive pulmonary disease and chronic pain n = 9 articles each. The theoretical frameworks most frequently cited were social cognitive theory and self-efficacy theory. Physical activity was the predominant focus of the self-management interventions. Physiotherapy programmes included disease-specific education, fatigue, posture, and pain management, while occupational therapists concentrated on joint protection, fatigue, and stress management. Conclusions: Physiotherapists and occupational therapists make moderate contributions to self-management interventions. Most of these interventions are disease-specific and are most frequently based on the principles of behaviour change theories.

The Role of Theory in Increasing Adherence to Prescribed Practice

PURPOSE The purpose of this article is to apply theoretical frameworks to adherence behaviour and to guide the development of an intervention to increase adherence to prescribed home programmes. SUMMARY OF KEY POINTS Delivering an effective intervention requires establishing one that is evidence based and of adequate dosage. Two-thirds of patients who receive home exercise prescriptions do not adhere to their home programme, which may contribute to their physiotherapys being ineffective. The mediating concepts of self-efficacy (SE) and outcome expectations (OE) are common to the five relevant theories used to explain adherence to exercise: the health belief model, protection motivation theory, theory of reasoned action, theory of planned behaviour, and social cognitive theory. CONCLUSION/RECOMMENDATIONS Few intervention studies with any theoretical underpinning have examined adherence to exercise. Even fewer have been designed to affect and measure change in the theoretical mediators of SE and OE in patient populations. Physiotherapists must consider increasing adherence as a component of effective physiotherapy. Ongoing research is needed to increase our understanding of adherence to prescribed home programmes and to design interventions to affect theoretical mediators for increasing adherence.

The effectiveness of community-based occupational therapy education and functional training programs for older adults: a critical literature review

Background. This paper examines the results of a critical literature review describing the provision of education and functional training programs by occupational therapists with older adults to maximize their occupational performance. Purpose. The critical review addressed the following question: What is the effectiveness of education and functional training programs in improving occupational performance and quality of life for older adults? Review methods are described and the outcomes of the critical review discussed. Results. The results indicate that there is evidence that programs are effective in three areas: prevention of functional decline and falls, stroke and rheumatoid arthritis. Methodological limitations exist in some studies. There are several randomized controlled studies in this area, though the description of specific occupational therapy interventions is often vague and the programs could not be easily duplicated by occupational therapists. Practice implications. Occupational therapists are provided with information through this critical review to facilitate evidence-based practice when working with older adults.

Perceptual and motor contributions to bimanual coordination

Following earlier work by Mechsner et al. (Nature 414 (2001) 69), the purpose of this experiment was to determine the perceptual and motoric contributions to bimanual coordination. Twenty right-handed, healthy, young adults performed continuous, horizontal, linear movements of both upper limbs at frequencies of 1.5 and 2.0 Hz. The goal was to control the spatial-temporal displacement of two flags by coordinating upper limb movements in two perceptual conditions. In a congruent condition, the movement of the flags matched the movement of the upper limbs. In an incongruent condition, the movement of the flags was opposite to the movement of the upper limbs. Measures of error in coordination provided support primarily for a motor view of bimanual coordination, and failed to replicate the earlier findings of Mechsner et al.

Aging, Attention, and Bimanual Coordination.

Although aging is normally associated with declines in motor performance, recent evidence suggests that older adults suffer no loss in some measures of bimanual coordination relative to younger adults. Two hypotheses for this finding were compared in the present research. One hypothesis was based on the assumption that these coordination patterns are automatic and relatively impervious to the effects of aging. An alternative explanation is that older adults maintain this level of bimanual coordination at a cost of increased attention demand. These hypotheses were tested in an experiment in which bimanual coordination patterns (in-phase and anti-phase) were paced at two metronome frequencies (1 and 2 Hz), either alone or together, with serial performance of an attention-demanding task (adding 3s to a two-digit number at a 1 Hz pace). The results of the study provided some support for both hypotheses. The automaticity view was supported only for the coordination patterns at the 1 Hz metronome frequency. Support for an attention allocation hypothesis was shown in the observed-movement frequency data, as older adults tended to sacrifice movement frequency at the 2 Hz metronome pace in order to maintain performance in the movement and counting tasks. These findings are discussed relative to recent accounts of the role of automaticity in the absence of age-related differences in the performance of cognitive tasks.