Effect of digital monitoring and counselling on self-management ability in patients with rheumatoid arthritis: a randomised controlled trial

OBJECTIVES

To assess a remote physiotherapist (PT) counselling intervention using self-monitoring tools for improving self-management ability, physical activity participation, and health outcomes in people with rheumatoid arthritis (RA).

METHODS

Eligible participants were randomly assigned to receive group education, a Fitbit®, a self-monitoring app, and PT counselling phone calls (Immediate Group). The Delayed Group received a monthly e-newsletter until week 26, and then the intervention. The primary outcome was Patient Activation Measure (PAM-13). Participants were assessed at baseline, 27 weeks (the primary end point) and 53 weeks. Secondary outcomes included disease activity, pain, fatigue, depression, sitting/walking habits, daily physical activity time, and daily awake sedentary time. Generalized Linear Mixed-effect Models (GLMMs) were used to assess the effect of the intervention on the change of each outcome measure from the initiation to 27 weeks after the intervention.

RESULTS

Analysis included 131 participants (91.6% women; 80.2% completed during the COVID-19 pandemic). The mean change of PAM-13 at 27 weeks was 4.6 (SD = 14.7) in the Immediate Group vs -1.6 (SD = 12.5) in the Delayed Group. The mean change in Delayed Group at 53 weeks (after the 26-week intervention) was 3.6 (SD = 14.6). Overall, the intervention improved PAM-13 at 27 weeks post-intervention from the GLMM analysis (adjusted coefficient: 5.3; 95% CI: 2.0, 8.7; p = <0.001). Favourable intervention effects were also found in disease activity, fatigue, depression, and self-reported walking habit.

CONCLUSION

Remote counselling paired with self-monitoring tools improved self-management ability in people with RA. Findings of secondary outcomes indicate that the intervention had a positive effect on symptom management.

Effects of Upper Limb Exercise or Training on Hand Dexterity and Function in People With Parkinson Disease: A Systematic Review and Meta-analysis

OBJECTIVE

This systematic review investigated the effects of exercise and training on hand dexterity and function outcomes in people with Parkinson disease (PD).

DATA SOURCES

We searched 5 databases (MEDLINE Ovid, CINAHL, PEDro, PubMed, Cochrane Database) from inception to October 2022.

STUDY SELECTION

Included studies were randomized controlled trials delivering upper limb exercise or training interventions to people with PD and evaluating 1 or more upper limb activity outcomes. Two independent reviewers screened 668 articles for inclusion.

DATA EXTRACTION

Two reviewers independently extracted data relating to study participants, intervention characteristics, and key outcomes. Cochrane Risk of Bias and GRADE tools assessed methodological quality of included studies, and strength of evidence for 3 outcomes: hand dexterity, self-reported hand function, and handwriting performance. Meta-analyses synthesized results for within-hand dexterity and self-reported function.

RESULTS

Eighteen randomized controlled trials (n=704) with low to unclear risk of bias were identified. Experimental interventions varied considerably in their approach and treatment dose, and 3 studies focused on training handwriting. Meta-analysis showed moderate quality evidence of a small positive effect on within-hand dexterity (SMD=0.26; 95% CI 0.07, 0.44). Very low-quality evidence pointed toward a nonsignificant effect on self-reported hand function (SMD=0.67; 95% CI -0.40, 1.75). A narrative review of handwriting interventions showed low quality evidence for improved performance after training.

CONCLUSIONS

There is moderate certainty of evidence supporting the use of exercise and training to address dexterity problems, but evidence remains unclear for self-reported hand function and handwriting. Our findings suggest that training could employ task-related approaches. Future research should interrogate aspects of clinical practice such as optimal dose and key ingredients for effective interventions.

Pilot of a Training Format for Clinicians' Continuing Professional Development: Open House With Rotating Short Segments

INTRODUCTION

Access to continuing professional development offered at lunchtime is limited by hospital scheduling that has staff members taking their lunch breaks at different times. To overcome this barrier, we developed a three-part training format with (1) a focus group segment soliciting participants' opinions on the training's target behavior, (2) a didactic segment introducing tools to support the behavior, and (3) a question-and-answer segment about the session topic. We rotated through these segments, each 15 minutes long, over 3 hours. Participants could join at any segment and experience the full curriculum after 45 minutes.

METHODS

We piloted this training format five times at three hospitals. Our training aimed to encourage clinicians to consistently inform involuntary patients about their Mental Health Act rights. We gauged the effect of the training and participants' opinions of the session using the Continuing Professional Development Reaction questionnaire and a session evaluation, respectively.

RESULTS

Continuing Professional Development-Reaction results (n = 80) showed a detectable increase in clinicians' intent to consistently give involuntary patients rights advice. Participants reported finding the training organized, informative, and valuable.

DISCUSSION

The open house with rotating short segments is a feasible and adaptable training format to engage clinicians in voluntary continuing professional development.

P03.06 Boolean logic puzzles as a neurosurgical mapping tool to preserve programming skill

BACKGROUND

In glioma surgery, awake craniotomy with Direct Electrical Stimulation (DES) is increasingly becoming the gold standard treatment to preserve language, cognition and motor function and to optimize extent of resection. Computer programming is historically seen as an integration of cognition, language, and mathematics but an intraoperative task to monitor computer programming does not exist yet. In this study we describe a new task for intraoperative monitoring, using visual Boolean Logic Puzzles.

MATERIAL AND METHODS

We describe a computer programmer who underwent awake craniotomy to resect an anaplastic astrocytoma in the left superior frontal gyrus. At the request of the patient we tested programming language. We developed a new task and set of logic puzzle visual stimuli to monitor underlying cognitive function used for programming language. This test was used during preoperative functional MRI (fMRI), direct electrical stimulation (DES) and ongoing monitoring during resection.

RESULTS

In fMRI this task showed bilateral activation in Brodmann area 6 and 8 and for left hemisphere in Brodmann area 10. These areas are below and lateral of the tumor. Monitoring of language, motor skills and Boolean mapping was performed during DES and while resection was performed. No deficits in programming ability could be identified intra- and postoperatively.

CONCLUSION

Boolean Logic Puzzles may be a useful intraoperative task to preserve programming skills.

Organizational supports for knowledge translation in paediatric health centres and research institutes: insights from a Canadian environmental scan

BACKGROUND

Organizational supports are thought to help address wide-ranging barriers to evidence-informed health care (EIHC) and knowledge translation (KT). However, little is known about the nature of the resources and services that exist within paediatric health care and research settings across Canada to facilitate evidence use in health care delivery. This survey examined existing supports for EIHC/KT within these organizations to inform the design of similar EIHC/KT support programmes.

METHODS

A national environmental scan was conducted using a bilingual online survey distributed to leaders at Canadian paediatric academic health science centres and their affiliated research institutes. Participants were invited through email, social media and webinar invitations and snowball sampling. Supports of interest included personnel, resources, services, organizational structures or processes, and partnerships or collaborations; barriers and successes were also probed. Data were compiled by site, reported using descriptive statistics, or grouped thematically. Supports were described using the AIMD (Aims, Ingredients, Mechanism, Delivery) framework.

RESULTS

Thirty-one respondents from 17 sites across seven provinces represented a 49% site response rate. Eleven (65%) sites reported an on-site library with variable staffing and services. Ten (59%) sites reported a dedicated KT support unit or staff person. Supports ranged from education, resource development and consultation to protocol development, funded initiatives and collaborations. Organizations leveraged internal and external supports, with the majority also employing supports for clinical research integration. Supports perceived as most effective included personnel, targeted initiatives, leadership, interdepartmental expertise, external drivers and logistical support. Barriers included operational constraints, individual-level factors and lack of infrastructure.

CONCLUSIONS

This first survey of organizational supports for EIHC/KT identified the range of supports in place in paediatric research and health care organizations across Canada. The diversity of supports reported across sites may reflect differences in resource capacity and objectives. Similarities in EIHC/KT and research integration supports suggest common infrastructure may be feasible. Moreover, stakeholder engagement in research was common, but not pervasive. Tailored support programmes can target multi-faceted barriers. Findings can inform the development, refinement and evaluation of EIHC/KT support programmes and guide the study of the effectiveness and sustainability of these strategies.

A qualitative study of clinicians' perspectives on independent rights advice for involuntary psychiatric patients in British Columbia, Canada

BACKGROUND

In British Columbia (BC), Canada, clinicians are responsible for giving involuntary psychiatric patients rights information upon admission. Yet an investigation by the BC Office of the Ombudsperson found that clinicians are not always fulfilling this responsibility. The Ombudsperson recommended that the provincial government fund an independent body to give rights advice to patients.

METHODS

To understand how clinicians feel about this recommendation, focus groups of clinicians who may give psychiatric patients rights information (n = 81) were conducted in Vancouver, BC, to probe their attitudes toward independent rights advisors. The focus group transcripts were thematically analyzed.

RESULTS

Most clinicians believe that giving rights information is within their scope of practice, although some acknowledge that it poses a conflict of interest when the patient wishes to challenge the treatment team's decisions. Participants' chief concerns about an independent rights-advice service were that (a) patients may experience a delay in receiving their rights information, (b) integrating rights advisors into the workflow would complicate an already chaotic admission process, and (c) more patients would be counselled to challenge their hospitalization, leading to an increased administrative workload for clinical staff. However, many participants believed that independent rights advisors would be a positive addition to the admission process, both allowing clinicians to focus on treatment and serving as a source of rights-related information.

CONCLUSIONS

Participants were generally amenable to an independent rights-advice service, suggesting that the introduction of rights advisors need not result in an adversarial relationship between treatment team and patient, as opponents of the proposal fear. Clearly distinguishing between basic rights information and in-depth rights advice could address several of the clinicians' concerns about the role that independent rights advisors would play in the involuntary admission process. Clinicians' and other stakeholders' concerns should be considered as the province develops its rights-advice service.

Examining Coronary Revascularization Practice Patterns for Diabetics: Perceived Barriers, Facilitators, and Implications for Knowledge Translation

BACKGROUND

The FREEDOM trial provided robust evidence that coronary artery bypass grafting (CABG) was superior to percutaneous coronary intervention (PCI) for coronary revascularization in patients with diabetes mellitus (DM) and multivessel coronary artery disease (MV-CAD). The present study examined practice pattern changes and perceived barriers and facilitators to implementing FREEDOM trial evidence in British Columbia (BC).

METHODS

Using a population-based database of cardiac procedures in BC, PCI:CABG ratios from 2007-2014 were compared before and after publication of the FREEDOM trial in the 4 tertiary cardiac centres that provided both CABG and PCI. Surveys of barriers and facilitators to implementation of evidence in practice were completed by 57 health care providers (HCPs) attending educational outreach sessions conducted in 2016-17 at 5 tertiary cardiac centres in BC.

RESULTS

The overall PCI:CABG ratio declined from 1.59 (95% confidence interval [CI] 1.48-1.70, range 1.16-1.86) before publication to 0.88 (95% CI 0.75-1.01, range 0.56-0.82) after publication (P < 0.01). This decline from before to after publication was significant in 3 centres, but not in the fourth centre (from 1.62 to 1.49; P = 0.61). Barriers were identified at the levels of evidence (applicability, credibility), HCP (awareness/knowledge, practice behaviours), patient (knowledge/misconceptions, preferences), and systems (siloing of care, financial disincentives, resource limitations, geography). Facilitators were additional studies/guidelines, education/dissemination, shared decision making, a heart team approach, changes to remuneration models, and increased resources.

CONCLUSIONS

Following publication of the FREEDOM trial, the proportion of patients with DM and MV-CAD undergoing CABG increased in BC; however, practice patterns varied across cardiac centres. HCPs attributed these practice variations to multilevel barriers and facilitators. Future knowledge translation strategies should be multifaceted and tailored to identified determinants.

Defining Critical Genes During Spherule Remodeling and Endospore Development in the Fungal Pathogen, Coccidioides posadasii

Coccidioides immitis and C. posadasii are soil dwelling dimorphic fungi found in North and South America. Inhalation of aerosolized asexual conidia can result in asymptomatic, acute, or chronic respiratory infection. In the United States there are approximately 350,000 new infections per year. The Coccidioides genus is the only known fungal pathogen to make specialized parasitic spherules, which contain endospores that are released into the host upon spherule rupture. The molecular determinants involved in this key step of infection remain largely elusive as 49% of genes are hypothetical with unknown function. An attenuated mutant strain C. posadasii Δcts2/Δard1/Δcts3 in which chitinase genes 2 and 3 were deleted was previously created for vaccine development. This strain does not complete endospore development, which prevents completion of the parasitic lifecycle. We sought to identify pathways active in the wild-type strain during spherule remodeling and endospore formation that have been affected by gene deletion in the mutant. We compared the transcriptome and volatile metabolome of the mutant Δcts2/Δard1/Δcts3 to the wild-type C735. First, the global transcriptome was compared for both isolates using RNA sequencing. The raw reads were aligned to the reference genome using TOPHAT2 and analyzed using the Cufflinks package. Genes of interest were screened in an in vivo model using NanoString technology. Using solid phase microextraction (SPME) and comprehensive two-dimensional gas chromatography - time-of-flight mass spectrometry (GC × GC-TOFMS) volatile organic compounds (VOCs) were collected and analyzed. Our RNA-Seq analyses reveal approximately 280 significantly differentially regulated transcripts that are either absent or show opposite expression patterns in the mutant compared to the parent strain. This suggests that these genes are tied to networks impacted by deletion and may be critical for endospore development and/or spherule rupture in the wild-type strain. Of these genes, 14 were specific to the Coccidioides genus. We also found that the wild-type and mutant strains differed significantly in their production versus consumption of metabolites, with the mutant displaying increased nutrient scavenging. Overall, our results provide the first targeted list of key genes that are active during endospore formation and demonstrate that this approach can define targets for functional assays in future studies.

Hand dexterity assessment in Parkinson's disease: construct validity of the 9-Hole peg test for the more affected hand

Purpose: There is limited understanding of the characteristics and evaluation of more affected hand dexterity loss in Parkinson's disease. We described 9-Hole Peg Test performance for the more affected hand and examined the construct validity of these pegboard scores in mild to severe Parkinson's disease. Methods: This observational study analysed baseline data from a cluster-randomised controlled trial.Participants (n = 582) completed the pegboard with their more affected hand, the Patient-Specific Index-Parkinson's Disease and Self-assessment Parkinson's Disease Disability Scale. Mean pegboard performance was summarised at each disease stage. To investigate known groups validity, we explored differences in pegboard scores between participants identifying upper limb problems in their 'top three' functional limitations, and those prioritising other limitations. Convergent validity investigated correlations between pegboard performance and self-reported hand function.Results: Pegboard performance was reduced compared with normative values, and problems with hand activities were reported at each disease stage. Significant differences in pegboard performance between the two functional limitation priority groups (p < 0.05), and moderate correlations between pegboard dexterity and hand function (Self-assessment Parkinson's Disease Disability Scale) provided evidence for construct validity.Conclusions: People with mild to severely disabling Parkinson's disease have reduced dexterity and problems with hand function. Evidence supported the construct validity of 9-Hole Peg Test more affected hand performance.IMPLICATIONS FOR REHABILITATIONPeople with mild to severely disabling PD experience dexterity loss and problems with hand function.It is important for clinicians to assess dexterity and hand function in people with this movement disorder.Evidence supports the construct validity of 9-Hole Peg Test for measuring more affected hand performance in Parkinson's disease.

Physiotherapy for freezing of gait in Parkinson's disease: a systematic review and meta-analysis

INTRODUCTION

Freezing of gait (FOG) is one of the most severe symptoms associated with Parkinson's disease (PD). Physiotherapy treatment could be an effective strategy for treating FOG, but no systematic review has been carried out in this regard.

AIM

To identify the characteristics, methodological quality, and main outcomes of the studies that have analyzed the effects of physiotherapy interventions in FOG up to date, by performing a systematic review and a meta-analysis.

PATIENTS AND METHODS

Four electronic databases were searched in order to find randomized controlled trials that provided information regarding the effects of any kind of physiotherapy treatment on FOG. The methodological quality of the included investigations was assessed by means of the PEDro scale.

RESULTS

Twelve studies were identified for inclusion into the qualitative analysis, with four randomized controlled trials included in the final meta-analysis. The quality of the trials was generally good. Those physiotherapy modalities including cues were more effective for treating FOG than traditional physiotherapy approaches. The meta-analysis indicated that physiotherapy interventions had a significantly greater impact on FOG than control comparisons.

CONCLUSIONS

Physiotherapy treatment, especially those modalities including visual and auditory cueing, should be prescribed to PD patients with FOG. Future studies including PD patients with cognitive impairment and FOG objective measurement tools are need to complete the existing scientific evidence.

Construct validity of the 9-Hole Peg Test and Purdue Pegboard Test in people with mild to moderately severe Parkinson's disease

OBJECTIVES

To evaluate the construct validity of two dexterity measures, the 9-Hole Peg Test (9HPT) and Purdue Pegboard Test (PPT) in people with Parkinson's disease (PD).

DESIGN

Cross-sectional observational study.

SETTING

Testing was conducted at the university or in participants' homes.

PARTICIPANTS

Thirty community dwelling people with mild to moderately severe PD and no major upper limb comorbidities or cognitive impairments.

INTERVENTIONS

Pegboard tests were administered in the 'on' and 'end-of-dose' phases of participants' PD medication cycles. Participants rated hand function with two self-report questionnaires - the Manual Ability Measure-36 (MAM-36) and a subset of upper limb items from the MDS-UPDRS. To explore construct validity, we compared 'on' phase pegboard scores with normative values for unimpaired men and women and investigated relationships between pegboard scores and hand function questionnaires.

RESULTS

In the 'on' phase, pegboard scores were poorer than normative values. Differences in individual subtest scores ranged between 10 and 41%. Correlations between self-reported hand function and pegboard scores were weak to moderately strong in the 'on' phase (r=0.21-0.51), and weak at 'end-of-dose' (r=0.13-0.22). Higher correlation coefficients were observed between hand function and PPT subtest scores than with hand function and 9HPT scores. Most participants reported difficulty with daily hand tasks.

CONCLUSIONS

We found evidence for construct validity supporting the use of the 9HPT and PPT to evaluate people with mild to moderately severe PD when 'on', but not at the 'end-of-dose'. Results also suggest that the PPT may be more sensitive to PD-related changes in dexterity than the 9HPT.

Measuring Hand Dexterity in People With Parkinson's Disease: Reliability of Pegboard Tests

IMPORTANCE

Knowledge regarding the reliability of pegboard tests when used to measure dexterity in people with Parkinson's disease (PD) is currently limited.

OBJECTIVE

To examine the test-retest and interrater reliability of the 9-Hole Peg Test (9HPT) and Purdue Pegboard Test (PPT) in people with PD.

DESIGN

Cross-sectional observational study. For test-retest reliability, tests were completed on 2 days, 1 wk apart, in the "on" phase and "end-of-dose" period of participants' medication cycle. For interrater reliability, occupational therapists and physical therapists rated prerecorded pegboard test performance of participants with PD.

SETTING

Test-retest reliability was determined in participants' homes or in a university department. Interrater reliability was determined in a university department or a hospital setting.

PARTICIPANTS

Test-retest reliability was determined with volunteers diagnosed with PD (N = 30). Interrater reliability was determined with a convenience sample of occupational and physical therapists (N = 11).

OUTCOMES AND MEASURES

The 9HPT and PPT are commonly used measures of manual dexterity.

RESULTS

PPT subtests showed higher test-retest reliability (intraclass correlation coefficients [ICCs] ≥ .90) in both phases of the medication cycle compared with the 9HPT (ICCs = .70-.81). Minimal detectable change scores indicated acceptable measurement error for both tools. Interrater reliability for recorded performance of each measure was very good (ICCs > .99), with no calculable measurement error.

CONCLUSIONS AND RELEVANCE

Although both tools showed adequate test-retest and interrater reliability, results suggest that the PPT may be a more reliable measure of dexterity loss in people with PD.

WHAT THIS ARTICLE ADDS

This study informs the clinical measurement of the loss of manual dexterity in people with PD, a frequent problem reported by people living with this disorder.

Metal Fatigue—Past, Current and Future

Metal fatigue has been a problem for more than 150 years, but because of rapid developments in fracture mechanics analyses, possibly at the expense of the traditional approach based on cyclic deformation processes, afar better understanding of fatigue failure behaviour has recently been achieved. Consequently the engineer now has the basic tools at his/her disposal to make good assessments of the numerous factors that control the fatigue lifetime of engineering materials, components and structures.

Additionally, more intensive interdisciplinary research studies involving chemists, materials scientists, mathematicians and physicists—but engineering led—have generated both greater insights into long-known industrial problems and routes to required solutions. This paper traces the growth of recent developments in understanding metal fatigue from the days of our mentors to the present day, and concludes with a brief review of some future research areas that are now available for exploitation.

Replacing stressful challenges with positive coping strategies: a resilience program for clinical placement learning

Clinical education is foundational to health professional training. However, it is also a time of increased stress for students. A student's perception of stressors and their capacity to effectively manage them is a legitimate concern for educators, because anxiety and decreased coping strategies can interfere with effective learning, clinical performance and capacity to care for patients. Resilience is emerging as a valuable construct to underpin positive coping strategies for learning and professional practice. We report the development and evaluation of a psycho-education resilience program designed to build practical skills-based resilience capacities in health science (physiotherapy) students. Six final year undergraduate physiotherapy students attended four action research sessions led by a clinical health psychologist. Resilience strategies drawn from cognitive behavioural therapy, and positive and performance psychology were introduced. Students identified personal learning stressors and their beliefs and responses. They chose specific resilience-based strategies to address them, and then reported their impact on learning performance and experiences. Thematic analysis of the audio-recorded and transcribed action research sessions, and students' de identified notes was conducted. Students' initial descriptions of stressors as 'problems' outside their control resulting in poor thinking and communication, low confidence and frustration, changed to a focus on how they managed and recognized learning challenges as normal or at least expected elements of the clinical learning environment. The research suggests that replacing stressful challenges with positive coping strategies offers a potentially powerful tool to build self-efficacy and cognitive control as well as greater self-awareness as a learner and future health practitioner.

Motor Planning for Loading During Gait in Subacute Stroke

OBJECTIVES

To determine the characteristics of motor planning surrounding initial contact during gait through examination of thigh muscle timing, amplitude, and co-contraction of the paretic and nonparetic limbs in people poststroke, and to investigate whether muscle timing, amplitude, and clinical performance measures of balance and mobility differ based on the level of co-contraction.

DESIGN

Observational study.

SETTING

University-based research laboratory.

PARTICIPANTS

Individuals (n=27) in the subacute phase after stroke and healthy controls (n=8) (N=35).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Timing (onset and offset) and normalized amplitude (percent electromyography maximum) of the biceps femoris (BF) and rectus femoris (RF) muscles were measured during terminal swing and early stance. A co-contraction index (CCI) was calculated for the BF and RF muscle activity. Individuals with CCI values equal to or below the mean of the healthy group were in the low CCI group, whereas those with values above the mean were in the high CCI group. Functional balance and mobility evaluation used the Community Balance and Mobility Scale (CB&M).

RESULTS

For the paretic and nonparetic limbs, measures of timing, amplitude, and co-contraction were similar for both limbs. Compared with the healthy group, the high CCI group had lower CB&M scores, longer durations, and higher levels of RF and BF muscle activity, whereas the low CCI group had electromyographic measures statistically similar to healthy controls.

CONCLUSIONS

The motor control of gait after subacute stroke is characterized by symmetry of timing and amplitude of muscle recruitment at the knee. High co-contraction levels surrounding the knee were associated with lower functional balance and mobility. These findings suggest a compensatory strategy of increased co-contraction in those with more impairment while maintaining symmetry of lower-limb biomechanics between limbs.

Therapists' perceptions of social media and video game technologies in upper limb rehabilitation

BACKGROUND

The application of technologies, such as video gaming and social media for rehabilitation, is garnering interest in the medical field. However, little research has examined clinicians' perspectives regarding technology adoption by their clients.

OBJECTIVE

The objective of our study was to explore therapists' perceptions of how young people and adults with hemiplegia use gaming and social media technologies in daily life and in rehabilitation, and to identify barriers to using these technologies in rehabilitation.

METHODS

We conducted two focus groups comprised of ten occupational therapists/physiotherapists who provide neurorehabilitation to individuals with hemiplegia secondary to stroke or cerebral palsy. Data was analyzed using inductive thematic analysis. The diffusion of innovations theory provided a framework to interpret emerging themes.

RESULTS

Therapists were using technology in a limited capacity. They identified barriers to using social media and gaming technology with their clients, including a lack of age appropriateness, privacy issues with social media, limited transfer of training, and a lack of accessibility of current systems. Therapists also questioned their role in the context of technology-based interventions. The opportunity for social interaction was perceived as a major benefit of integrated gaming and social media.

CONCLUSIONS

This study reveals the complexities associated with adopting new technologies in clinical practice, including the need to consider both client and clinician factors. Despite reporting several challenges with applying gaming and social media technology with clinical populations, therapists identified opportunities for increased social interactions and were willing to help shape the development of an upper limb training system that could more readily meet the needs of clients with hemiplegia. By considering the needs of both therapists and clients, technology developers may increase the likelihood that clinicians will adopt innovative technologies.

Instrumenting gait assessment using the Kinect in people living with stroke: reliability and association with balance tests

Background

The Microsoft Kinect has been used previously to assess spatiotemporal aspects of gait; however the reliability of this system for the assessment of people following stroke has not been established. This study examined the reliability and additional information that the Kinect provides when instrumenting a gait assessment in people living with stroke.

Methods

The spatiotemporal variables of step length, step length asymmetry, foot swing velocity, foot swing velocity asymmetry, peak and mean gait speed and the percentage difference between the peak and mean gait speed were assessed during gait trials in 30 outpatients more than three months post-stroke and able to stand unsupported. Additional clinical assessments of functional reach (FR), step test (ST), 10 m walk test (10MWT) and the timed up and go (TUG) were performed, along with force platform instrumented assessments of center of pressure path length velocity during double-legged standing balance with eyes closed (DLEC), weight bearing asymmetry (WBA) and dynamic medial-lateral weight-shifting ability (MLWS). These tests were performed on two separate occasions, seven days apart for reliability assessment. Separate adjusted multiple regressions models for predicting scores on the clinical and force platform assessments were created using 1) the easily assessed clinically-derived gait variables 10MWT time and total number of steps; and 2) the Kinect-derived variables which were found to be reliable (ICC > 0.75) and not strongly correlated (Spearman’s ρ < 0.80) with each other (i.e. non-redundant).

Results

Kinect-derived variables were found to be highly reliable (all ICCs > 0.80), but many were redundant. The final regression model using Kinect-derived variables consisted of the asymmetry scores, mean gait velocity, affected limb foot swing velocity and the difference between peak and mean gait velocity. In comparison with the clinically-derived regression model, the Kinect-derived model accounted for >15% more variance on the MLWS, ST and FR tests and scored similarly on all other measures.

Conclusions

In conclusion, instrumenting gait using the Kinect is reliable and provides insight into the dynamic balance capacity of people living with stroke. This system provides a minimally intrusive method of examining potentially important gait characteristics in people living with stroke.

Perceptions of Technology and Its Use for Therapeutic Application for Individuals With Hemiparesis: Findings From Adult and Pediatric Focus Groups

BACKGROUND

Digital technology is becoming an increasingly popular means of delivering meaningful therapy to individuals with neurological impairments. An understanding of clients' technology use and their perspectives on incorporating technology into rehabilitation can provide researchers and designers with valuable information to inform development of technologies and technology-based rehabilitation programs.

OBJECTIVE

This study was designed to establish the current use and perceptions of gaming, social media, and robotics technologies for rehabilitative purposes from the perspective of adults and children with upper limb impairments to identify barriers and enablers to their adoption and use.

METHODS

We conducted three focus groups consisting of pediatric (n=7, mean age 11.0 years) and adult (n=8, mean age 60.8 years) participants with hemiparesis affecting their upper limb. We applied thematic analysis methods to the resulting data.

RESULTS

We identified three key themes: (1) clients' use of technology in everyday life and rehabilitation, (2) barriers to use, and (3) enablers to therapy. Participants had limited exposure to technology for therapeutic purposes, but all acknowledged the potential benefits in providing motivation and interest for the performance of repetitive task practice. Adult participants requested efficacious, simple, and easy-to-use technology for rehabilitation with programs that could be individualized for them and expressed that they wanted these programs to provide a motivating means of repeated practice of therapeutic movements. In contrast, pediatric participants emphasized a desire for technology for rehabilitation that offered opportunities for social interaction and interactive games involving their whole body and not only their affected limb. Perceived safety and privacy were concerns for both groups.

CONCLUSIONS

Our findings highlight that all participants were open to the integration of technology into rehabilitation. Adult participants were more pragmatically motivated by potential recovery gains, whereas pediatric participants were more intrinsically motivated by access to games.

Instrumented static and dynamic balance assessment after stroke using Wii Balance Boards: reliability and association with clinical tests

Background and Objectives

The Wii Balance Board (WBB) is a globally accessible device that shows promise as a clinically useful balance assessment tool. Although the WBB has been found to be comparable to a laboratory-grade force platform for obtaining centre of pressure data, it has not been comprehensively studied in clinical populations. The aim of this study was to investigate the measurement properties of tests utilising the WBB in people after stroke.

Methods

Thirty individuals who were more than three months post-stroke and able to stand unsupported were recruited from a single outpatient rehabilitation facility. Participants performed standardised assessments incorporating the WBB and customised software (static stance with eyes open and closed, static weight-bearing asymmetry, dynamic mediolateral weight shifting and dynamic sit-to-stand) in addition to commonly employed clinical tests (10 Metre Walk Test, Timed Up and Go, Step Test and Functional Reach) on two testing occasions one week apart. Test-retest reliability and construct validity of the WBB tests were investigated.

Results

All WBB-based outcomes were found to be highly reliable between testing occasions (ICC  = 0.82 to 0.98). Correlations were poor to moderate between WBB variables and clinical tests, with the strongest associations observed between task-related activities, such as WBB mediolateral weight shifting and the Step Test.

Conclusions

The WBB, used with customised software, is a reliable and potentially useful tool for the assessment of balance and weight-bearing asymmetry following stroke. Future research is recommended to further investigate validity and responsiveness.

Molecular genetics to inform spatial management in benthic invertebrate fisheries: a case study using the Australian greenlip abalone

Hierarchical sampling and subsequent microsatellite genotyping of >2300 Haliotis laevigata (greenlip abalone) from 19 locations distributed across five biogeographic regions have substantially advanced our knowledge of population structure and connectivity in this commercially important species. The study has found key differences in stock structure of H. laevigata compared with the sympatric and congeneric Haliotis rubra (blacklip abalone) and yielded valuable insights into the management of fisheries targeting species characterized by spatial structure at small scales (i.e. S-fisheries). As with H. rubra, H. laevigata comprise a series of metapopulations with strong self-recruitment. However, the spatial extent of H. laevigata metapopulations (reefal areas around 30 km(2) ; distances of up to 135 km are effective barriers to larval dispersal) was substantially greater than that identified for H. rubra (Miller et al. 2009). Differences in the dynamics and scale of population processes, even between congeneric haliotids as made evident in this study, imply that for S-fisheries, it is difficult to generalize about the potential consequences of life history commonalities. Consequently, species-specific management reflective of the population structure of the target species remains particularly important. This will likely require integration of information about stock structure and connectivity with data on life history and population dynamics to determine the necessary input (e.g. number of fishers, fishing effort) and output (e.g. minimum legal size, total allowable catch) controls to underpin their sustainable management.

Protocol for a randomized controlled clinical trial investigating the effectiveness of Fast muscle Activation and Stepping Training (FAST) for improving balance and mobility in sub-acute stroke

Background

Following stroke, many people have difficulty activating their paretic muscles quickly and with sufficient power to regain their balance by taking quick and effective steps. Reduced dynamic balance and mobility following stroke, or ‘walking balance’, is associated with reduced self-efficacy and restrictions in daily living activities, community integration, and quality of life. Targeted training of movement speeds required to effectively regain balance has been largely overlooked in post-stroke rehabilitation. The Fast muscle Activation and Stepping Training (FAST) program incorporates fast functional movements known to produce bursts of muscle activation essential for stepping and regaining standing balance effectively. The purpose of this study is to: 1) compare the effectiveness of an outpatient FAST program to an active control outpatient physiotherapy intervention in improving walking balance following stroke, and 2) explore potential mechanisms associated with improvements in walking balance.

Methods/Design

This will be an assessor-blinded, parallel group randomized controlled trial design. Sixty participants (30 per group) who have sustained a stroke within the previous six months will be randomly assigned with stratification for lower limb motor recovery to receive twelve 45-minute 1:1 physiotherapy intervention sessions over 6 – 10 weeks in an outpatient setting of either: 1) FAST intervention - systematic and progressive practice of fast squatting and stepping exercises, or 2) active control - conventional physiotherapy directed at improving balance and mobility that includes no targeted fast movement training. The same blinded research physiotherapist will assess outcomes at three time points: 1) baseline (prior to intervention), 2) follow up (within one week post-intervention); and 3) retention (one month post-intervention). The primary outcome is dynamic balance assessed using the Community Balance and Mobility Scale. We will also assess fast and self-selected walking speed, balance self-efficacy, and the ability to respond to internal and external perturbations to balance and associated changes in postural muscle activation.

Discussion

The targeted training of fast functional movements in the FAST program is expected to improve walking balance following stroke compared to the active control intervention. Unique to this study is the investigation of potential mechanisms associated with improvements in walking balance.

Trial registration

NCT01573585

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-014-0187-y) contains supplementary material, which is available to authorized users.

Stimulus Dependence of Gamma Oscillations in Human Visual Cortex

A striking feature of some field potential recordings in visual cortex is a rhythmic oscillation within the gamma band (30-80 Hz). These oscillations have been proposed to underlie computations in perception, attention, and information transmission. Recent studies of cortical field potentials, including human electrocorticography (ECoG), have emphasized another signal within the gamma band, a nonoscillatory, broadband signal, spanning 80-200 Hz. It remains unclear under what conditions gamma oscillations are elicited in visual cortex, whether they are necessary and ubiquitous in visual encoding, and what relationship they have to nonoscillatory, broadband field potentials. We demonstrate that ECoG responses in human visual cortex (V1/V2/V3) can include robust narrowband gamma oscillations, and that these oscillations are reliably elicited by some spatial contrast patterns (luminance gratings) but not by others (noise patterns and many natural images). The gamma oscillations can be conspicuous and robust, but because they are absent for many stimuli, which observers can see and recognize, the oscillations are not necessary for seeing. In contrast, all visual stimuli induced broadband spectral changes in ECoG responses. Asynchronous neural signals in visual cortex, reflected in the broadband ECoG response, can support transmission of information for perception and recognition in the absence of pronounced gamma oscillations.

Clinical feasibility of the Nintendo Wii™ for balance training post-stroke: a phase II randomized controlled trial in an inpatient setting

OBJECTIVE

To investigate the feasibility and potential efficacy of the Nintendo Wii™ for balance rehabilitation after stroke.

DESIGN

Phase II, single-blind, randomized controlled trial.

SETTING

Inpatient rehabilitation facility.

SUBJECTS

Thirty adults (mean age 63.6 (14.7) years) undergoing inpatient rehabilitation who were less than three months post-stroke and able to stand unsupported.

INTERVENTIONS

Participants were allocated to a Balance Group, using the 'Wii Fit Plus' in standing, or Upper Limb Group, using the 'Wii Sports/Sports Resort' in sitting. Both groups undertook three 45 minute sessions per week over two to four weeks in addition to standard care.

MAIN MEASURES

The primary focus was feasibility, addressed by recruitment, retention, adherence, acceptability and safety. Efficacy was evaluated by balance, mobility and upper limb outcomes.

RESULTS

Twenty-one percent of individuals screened were recruited and 86% (n = 30) of eligible people agreed to participate. Study retention and session adherence was 90% and > 99%, respectively, at two weeks; dropping to 70% and 87% at four weeks due to early discharge. All participants reported enjoying the sessions and most felt they were beneficial. No major adverse events occurred. Wii use by the Balance Group was associated with trends for improved balance, with significantly greater improvement in outcomes including the Step Test and Wii Balance Board-derived centre of pressure scores. The Upper Limb Group had larger, non-significant changes in arm function.

CONCLUSIONS

A Wii-based approach appears feasible and promising for post-stroke balance rehabilitation. A larger randomized controlled trial is recommended to further investigate efficacy.

Effectiveness and feasibility of virtual reality and gaming system use at home by older adults for enabling physical activity to improve health-related domains: a systematic review

BACKGROUND

use of virtual reality and commercial gaming systems (VR/gaming) at home by older adults is receiving attention as a means of enabling physical activity.

OBJECTIVE

to summarise evidence for the effectiveness and feasibility of VR/gaming system utilisation by older adults at home for enabling physical activity to improve impairments, activity limitations or participation.

METHODS

a systematic review searching 12 electronic databases from 1 January 2000-10 July 2012 using key search terms. Two independent reviewers screened yield articles using pre-determined selection criteria, extracted data using customised forms and applied the Cochrane Collaboration Risk of Bias Tool and the Downs and Black Checklist to rate study quality.

RESULTS

fourteen studies investigating the effects of VR/gaming system use by healthy older adults and people with neurological conditions on activity limitations, body functions and physical impairments and cognitive and emotional well-being met the selection criteria. Study quality ratings were low and, therefore, evidence was not strong enough to conclude that interventions were effective. Feasibility was inconsistently reported in studies. Where feasibility was discussed, strong retention (≥70%) and adherence (≥64%) was reported. Initial assistance to use the technologies, and the need for monitoring exertion, aggravation of musculoskeletal symptoms and falls risk were reported.

CONCLUSIONS

existing evidence to support the feasibility and effectiveness VR/gaming systems use by older adults at home to enable physical activity to address impairments, activity limitations and participation is weak with a high risk of bias. The findings of this review may inform future, more rigorous research.

Upper-limb assessment in people with Parkinson disease: is it a priority for therapists, and which assessment tools are used?

PURPOSE

To investigate the frequency of physiotherapy and occupational therapy assessment of the upper limb (UL) in people with Parkinson disease (PD) and to identify the impairments and activity limitations assessed and the methods used.

METHOD

A custom-designed questionnaire was used to survey physiotherapists and occupational therapists with previous experience in managing people with PD, using targeted recruitment to invite physiotherapy conference attendees, clinicians employed in movement disorders programmes, and practitioners in neurology and gerontology to respond either on paper or online.

RESULTS

Of the 190 respondents (122 physiotherapists, 68 occupational therapists), 54% reported consistently assessing the UL. A majority (>60%) assessed impairments specific to PD, but few quantified these using standardized measures. Activity limitations, largely relating to manual dexterity, were assessed using observational analysis (61%), non-standardized timed activities (46%), and standardized outcome measures (61%), most generic or developed for evaluating other neurological conditions. More than 10% of respondents could not identify an appropriate standardized measure.

CONCLUSIONS

Slightly more than half of respondents regularly assessed the UL. Respondents reported widespread use of non-standardized methods to assess PD-specific impairments. Standardized measures were more frequently used to evaluate activity limitations, but despite the unique movement disorders associated with PD, the clinimetric properties of most of the tools identified have not been established in this population. Education and further clinimetric investigation of measures in use are needed to facilitate evidence-based practice in this area.

Postural control and fear of falling assessment in people with chronic obstructive pulmonary disease: a systematic review of instruments, international classification of functioning, disability and health linkage, and measurement properties

OBJECTIVES

To systematically review the instruments used to assess postural control and fear of falling in people with chronic obstructive pulmonary disease (COPD), and to synthesize and evaluate their breadth of content and measurement properties.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, CINAHL, CENTRAL, PsycINFO, PEDro, and OTSeeker databases searched in September 2012.

STUDY SELECTION

Two independent reviewers performed the selection of articles, the ICF linking process and quality assessment. Only quantitative studies were included, irrespective of language or publication date.

DATA EXTRACTION

This systematic review comprised two phases. Phase 1 aimed to identify the commonly used instruments to assess postural control and fear of falling in the COPD literature. The breadth of content of each instrument was examined based on the International Classification of Functioning, Disability and Health (ICF). In phase 2, a measurement property search filter was adopted and used in four electronic databases to retrieve properties reported in the COPD population. The COSMIN checklist was used to assess the methodological quality of each measurement property reported.

DATA SYNTHESIS

Seventeen out of 401 publications were eligible in phase 1. Seventeen instruments were identified including 15 for postural control and 2 for fear of falling assessment. The Berg Balance Scale, the Short Physical Performance Battery, and the Activities-specific Balance Confidence (ABC) scale were the most frequently used instruments to assess postural control and fear of falling respectively. The ICF categories covered varied considerably among instruments. The Balance Evaluation Systems test and ABC presented the greatest breadth of content. Measurement properties reported included criterion predictive validity (4 instruments), construct validity (11 instruments) and responsiveness (1 instrument), with inconsistent findings based on 'fair' and 'poor' quality studies.

CONCLUSIONS

Different instruments with heterogeneous content have been used to assess postural control and fear of falling outcomes. Standardized assessment methods and best evidence on measurement properties is required in the COPD literature.

Feasibility and Efficacy of the Nintendo Wii Gaming System to Improve Balance Performance Post-Stroke: Protocol of a Phase II Randomized Controlled Trial in an Inpatient Rehabilitation Setting

OBJECTIVE

Balance deficits following stroke are common and debilitating. Commercially available gaming systems, such as the Nintendo(®) (Kyoto, Japan) Wii™, have been widely adopted clinically; however, there is limited evidence supporting their feasibility and efficacy for improving balance performance following stroke. The aim of this trial is to investigate the clinical feasibility and efficacy of using the Nintendo Wii gaming system as an adjunct to standard care to improve balance performance following stroke in an inpatient rehabilitation setting.

SUBJECTS AND METHODS

Thirty participants undergoing inpatient stroke rehabilitation will be recruited into this Phase II, single-blind, randomized controlled trial. Participants will be allocated into a Balance or Upper Limb Group, and both groups will perform activities using the Nintendo Wii in addition to their standard care. Participants will attend three 45-minute sessions per week, for a minimum of 2 and a maximum of 4 weeks.

RESULTS

The main focus of the study is to investigate the feasibility of the intervention protocol. This will be evaluated through recruitment, retention, adherence, acceptability, and safety. The Step Test and Functional Reach Test will be the primary efficacy outcomes. Secondary outcomes will include force platform, mobility, and upper limb measures. Assessments will occur at baseline, 2 weeks, and 4 weeks after study entry.

DISCUSSION

To the authors' knowledge, this will be the largest randomized clinical trial to investigate the feasibility and efficacy of the Nintendo Wii gaming system for improving balance performance in a stroke population. The results will inform the design of a Phase III multicenter trial.

Prior knowledge improves decoding of finger flexion from electrocorticographic signals

Brain–computer interfaces (BCIs) use brain signals to convey a user’s intent. Some BCI approaches begin by decoding kinematic parameters of movements from brain signals, and then proceed to using these signals, in absence of movements, to allow a user to control an output. Recent results have shown that electrocorticographic (ECoG) recordings from the surface of the brain in humans can give information about kinematic parameters (e.g., hand velocity or finger flexion). The decoding approaches in these studies usually employed classical classification/regression algorithms that derive a linear mapping between brain signals and outputs. However, they typically only incorporate little prior information about the target movement parameter. In this paper, we incorporate prior knowledge using a Bayesian decoding method, and use it to decode finger flexion from ECoG signals. Specifically, we exploit the constraints that govern finger flexion and incorporate these constraints in the construction, structure, and the probabilistic functions of the prior model of a switched non-parametric dynamic system (SNDS). Given a measurement model resulting from a traditional linear regression method, we decoded finger flexion using posterior estimation that combined the prior and measurement models. Our results show that the application of the Bayesian decoding model, which incorporates prior knowledge, improves decoding performance compared to the application of a linear regression model, which does not incorporate prior knowledge. Thus, the results presented in this paper may ultimately lead to neurally controlled hand prostheses with full fine-grained finger articulation.

Thickness in entorhinal and subicular cortex predicts episodic memory decline in mild cognitive impairment

Identifying subjects with mild cognitive impairment (MCI) most likely to decline in cognition over time is a major focus in Alzheimer's disease (AD) research. Neuroimaging biomarkers that predict decline would have great potential for increasing the efficacy of early intervention. In this study, we used high-resolution MRI, combined with a cortical unfolding technique to increase visibility of the convoluted medial temporal lobe (MTL), to assess whether gray matter thickness in subjects with MCI correlated to decline in cognition over two years. We found that thickness in the entorhinal (ERC) and subicular (Sub) cortices of MCI subjects at initial assessment correlated to change in memory encoding over two years (ERC: r = 0.34; P = .003) and Sub (r = 0.26; P = .011) but not delayed recall performance. Our findings suggest that aspects of memory performance may be differentially affected in the early stages of AD. Given the MTL's involvement in early stages of neurodegeneration in AD, clarifying the relationship of these brain regions and the link to resultant cognitive decline is critical in understanding disease progression.

Evidence that disease-induced population decline changes genetic structure and alters dispersal patterns in the Tasmanian devil

Infectious disease has been shown to be a major cause of population declines in wild animals. However, there remains little empirical evidence on the genetic consequences of disease-mediated population declines, or how such perturbations might affect demographic processes such as dispersal. Devil facial tumour disease (DFTD) has resulted in the rapid decline of the Tasmanian devil, Sarcophilus harrisii, and threatens to cause extinction. Using 10 microsatellite DNA markers, we compared genetic diversity and structure before and after DFTD outbreaks in three Tasmanian devil populations to assess the genetic consequences of disease-induced population decline. We also used both genetic and demographic data to investigate dispersal patterns in Tasmanian devils along the east coast of Tasmania. We observed a significant increase in inbreeding (F(IS) pre/post-disease -0.030/0.012, P<0.05; relatedness pre/post-disease 0.011/0.038, P=0.06) in devil populations after just 2-3 generations of disease arrival, but no detectable change in genetic diversity. Furthermore, although there was no subdivision apparent among pre-disease populations (θ=0.005, 95% confidence interval (CI) -0.003 to 0.017), we found significant genetic differentiation among populations post-disease (θ=0.020, 0.010-0.027), apparently driven by a combination of selection and altered dispersal patterns of females in disease-affected populations. We also show that dispersal is male-biased in devils and that dispersal distances follow a typical leptokurtic distribution. Our results show that disease can result in genetic and demographic changes in host populations over few generations and short time scales. Ongoing management of Tasmanian devils must now attempt to maintain genetic variability in this species through actions designed to reverse the detrimental effects of inbreeding and subdivision in disease-affected populations.

The AsTex: clinimetric properties of a new tool for evaluating hand sensation following stroke

OBJECTIVES

To investigate the clinimetric properties and clinical utility of the AsTex((R)), a new clinical tool for evaluation of hand sensation following stroke.

DESIGN

The AsTex((R)) was administered on two occasions separated by a week to appraise test-retest reliability, and by three assessors on single occasion to establish inter-rater reliability. Pilot normative values were collected in an age-stratified sample. Clinical utility was evaluated based on ease of administration, ceiling and floor effects, and responsiveness to sensory recovery.

PARTICIPANTS

Test-retest (n = 31) and inter-rater (n = 31) reliability and normative values (n = 95) for the AsTex((R)) were established in neurologically normal participants aged 18-85 years. Test-retest reliability was investigated in 22 individuals a mean of 46 months (range 12-125) post stroke and clinical utility was evaluated in an additional 24 subacute stroke participants a mean of 29.4 days (range 12-41) post stroke.

MAIN MEASURE

The AsTex((R)).

RESULTS

The AsTex((R)) demonstrated excellent test-retest (intraclass correlation coefficient (ICC) = 0.98, 95% confidence interval (95% CI) = 0.97-0.99) and inter-rater reliability (ICC = 0.81, 95% CI = 0.73-0.87) in neurologically normal participants. Test-retest reliability of the AsTex((R)) in individuals following stroke was excellent (ICC = 0.86, 95% CI = 0.68-0.94). The AsTex((R)) was simple to administer, demonstrated small standard error of measurement (0.14 mm), minimal floor and ceiling effects (12.5% and 8.3%) and excellent responsiveness (standardized response mean = 0.57) in subacute stroke participants.

CONCLUSION

The AsTex((R)) is a reliable, clinically useful and responsive tool for evaluating hand sensation following stroke.

High gamma mapping using EEG

High gamma (HG) power changes during motor activity, especially at frequencies above 70 Hz, play an important role in functional cortical mapping and as control signals for BCI (brain-computer interface) applications. Most studies of HG activity have used ECoG (electrocorticography) which provides high-quality spatially localized signals, but is an invasive method. Recent studies have shown that non-invasive modalities such as EEG and MEG can also detect task-related HG power changes. We show here that a 27 channel EEG (electroencephalography) montage provides high-quality spatially localized signals non-invasively for HG frequencies ranging from 83 to 101 Hz. We used a generic head model, a weighted minimum norm least squares (MNLS) inverse method, and a self-paced finger movement paradigm. The use of an inverse method enables us to map the EEG onto a generic cortex model. We find the HG activity during the task to be well localized in the contralateral motor area. We find HG power increases prior to finger movement, with average latencies of 462 ms and 82 ms before EMG (electromyogram) onset. We also find significant phase-locking between contra- and ipsilateral motor areas over a similar HG frequency range; here the synchronization onset precedes the EMG by 400 ms. We also compare our results to ECoG data from a similar paradigm and find EEG mapping and ECoG in good agreement. Our findings demonstrate that mapped EEG provides information on two important parameters for functional mapping and BCI which are usually only found in HG of ECoG signals: spatially localized power increases and bihemispheric phase-locking.

Genetic diversity and gene flow in collapsed and healthy abalone fisheries

Overexploitation of marine species invariably results in population decline but can also have indirect effects on ecological processes such as larval dispersal and recruitment that ultimately affect genetic diversity and population resilience. We compared microsatellite DNA variation among depleted and healthy populations of the black-lip abalone Haliotis rubra from Tasmania, Australia, to determine if over-fishing had affected genetic diversity. We also used genetic data to assess whether variation in the scale and frequency of larval dispersal was linked to greater population decline in some regions than in others, and if larval dispersal was sufficient to facilitate natural recovery of depleted populations. Surprisingly, allelic diversity was higher in depleted populations than in healthy populations (P < 0.05). Significant subdivision across hundreds of metres among our sampling sites (F(ST) = 0.026, P < 0.01), coupled with assignment tests, indicated that larval dispersal is restricted in all regions studied, and that abalone populations across Tasmania are largely self-recruiting. Low levels of larval exchange appear to occur at the meso-scale (7-20 km), but age estimates based on shell size indicated that successful migration of larvae between any two sites may happen only once every few years. We suggest that genetic diversity may be higher in depleted populations due to the higher relative ratio of migrant to self-recruiting larvae. In addition, we expect that recovery of depleted abalone populations will be reliant on sources of larvae at the meso-scale (tens of km), but that natural recovery is only likely to occur on a timescale unacceptable to fishers and resource managers.

Testing for nested oscillation

Nested oscillation occurs when the amplitude of a faster rhythm is coupled to the phase of a slower rhythm. It has been proposed to underlie the discrete nature of perception and the capacity of working memory and is a phenomenon observable in human brain imaging data. This paper compares three published methods for detecting nested oscillation and a fourth method proposed in this paper. These are: (i) the modulation index, (ii) the phase-locking value (PLV), (iii) the envelope-to-signal correlation (ESC) and (iv) a general linear model (GLM) measure derived from ESC. We applied the methods to electrocorticographic (ECoG) data recorded during a working-memory task and to data from a simulated hippocampal interneuron network. Further simulations were then made to address the dependence of each measure on signal to noise level, coupling phase, epoch length, sample rate, signal nonstationarity, and multi-phasic coupling. Our overall conclusion is that the GLM measure is the best all-round approach for detecting nested oscillation.

Two-dimensional movement control using electrocorticographic signals in humans

We show here that a brain-computer interface (BCI) using electrocorticographic activity (ECoG) and imagined or overt motor tasks enables humans to control a computer cursor in two dimensions. Over a brief training period of 12-36 min, each of five human subjects acquired substantial control of particular ECoG features recorded from several locations over the same hemisphere, and achieved average success rates of 53-73% in a two-dimensional four-target center-out task in which chance accuracy was 25%. Our results support the expectation that ECoG-based BCIs can combine high performance with technical and clinical practicality, and also indicate promising directions for further research.

Experimental and theoretical fatigue-crack propagation lives of variously notched plates

The fatigue lives of variously notched plates have been determined theoretically and experimentally. Theoretical predictions of fatigue lives involved the determination of stress-intensity factors from finite-element analyses. By invoking a crack propagation law, fatigue-life predictions were made for four specimens.

Fatigue experiments were conducted on four notched plates subjected to end load plus bending. Comparison with theoretical results shows that the experimental lives were greater by factors of 1.30 to 1.54. These results are most satisfactory since (1) a safe prediction of fatigue life has been made for a complex profile subjected to non-simple loading conditions, and (2) a theoretical elastic analysis has sufficed for a situation involving plastic strains.

Cyclic behaviour of materials

The effect of strain rate on the cyclic behaviour of two materials is presented. For the material that cyclically hardens (En 32B) a decrease in strain rate decreases the maximum cyclic hardening of the material, whilst for a material that cyclically softens (En 25) a decrease in the rate of deformation increases the maximum cyclic softening. It is concluded that the effect of strain rate on the cyclic stress-strain curve should be more closely studied than the effect of frequency since the frequency may be constant whilst the straining rate may vary considerably in plastically deformed zones. For those zones that suffer low strain rates the inclusion of time-dependent deformation processes can maximize the degree of softening or minimize the degree of hardening, thereby creating a greater localization of the plastic strain which should increase strain-concentration factors. Finally it is argued that it is better to predict fatigue behaviour from an incremental-step high-strain fatigue test on a single specimen than from static-test data. For the same reasons correlations between static tests and fatigue tests should be discouraged, especially for those materials that exhibit marked cyclic softening.

An experimental linear cumulative-damage law

An hypothesis of cumulative damage is presented that may be expressed mathematically as Σn÷Nf = constant where n is the number of cycles performed at a constant strain range and strain rate and Nf is the number of cycles to failure at the same strain range and strain rate.

An initial experimental investigation at room temperature shows that, under constant strain-rate conditions, the load-sequence effect is removed, but the value of the constant is dependent on the definition of failure. If failure is defined as complete rupture the summation term is less than unity whatever the sequence of loading. Should failure be defined as the termination of the steady-state period, that is at the point of crack growth instability, then the summation term is greater than unity. This latter definition therefore leads to a linear law of cumulative damage that gives a doubly cautious prediction of life that is of obvious advantage to engineers.

Effect of strain rate on low-endurance torsional fatigue in commercially pure aluminium

Commercially pure (99 per cent) aluminium has been subjected to high-strain low-endurance torsional fatigue under conditions of constant strain rate. (In this paper ‘strain’ and ‘strain rate’ refer to conditions at the surface of the specimen and therefore apply to the zones in which cracks are initiated.) Tests were performed at 20°C (0.315TM) and were controlled between constant torque limits of equal but reversed magnitudes. Below a critical strain rate, ·λcrit, the fatigue life obeys the law

Nf = A·λm

for a constant torque range. When ·λ exceeds ·λcrit, there is no significant strain-rate effect on fatigue endurance. It is suggested that cyclically activated creep mechanisms cause significant damage at strain rates less than 2Tcrit.

A relaxation behaviour was observed after the first quarter cycle when torque ranges were greater than a critical level of 2 Tcrit. A similar phenomenon was observed at ranges less than 2 Tcrit with straining rates less than 2Tcrit but only when the specimens were close to failure and the initial cyclic hardening had been removed by cyclic softening. In consequence fatigue endurances were found to be less sensitive to torque at ranges greater than 2 Tcrit.

Cumulative strain (cyclically induced creep) occurred at all torque ranges and straining rates. Minimum cumulative strains occurred at a torque range of 2 Tcrit with the value of Tcrit having a minimal dependence on the straining rate.

The ratio of time to cyclic-dependent processes that contribute to failure is itself dependent on both the torque range and the straining rate. However, a single curve suffices to represent all results if a total strain path to failure criterion is adopted.

Decoding two-dimensional movement trajectories using electrocorticographic signals in humans

Signals from the brain could provide a non-muscular communication and control system, a brain-computer interface (BCI), for people who are severely paralyzed. A common BCI research strategy begins by decoding kinematic parameters from brain signals recorded during actual arm movement. It has been assumed that these parameters can be derived accurately only from signals recorded by intracortical microelectrodes, but the long-term stability of such electrodes is uncertain. The present study disproves this widespread assumption by showing in humans that kinematic parameters can also be decoded from signals recorded by subdural electrodes on the cortical surface (ECoG) with an accuracy comparable to that achieved in monkey studies using intracortical microelectrodes. A new ECoG feature labeled the local motor potential (LMP) provided the most information about movement. Furthermore, features displayed cosine tuning that has previously been described only for signals recorded within the brain. These results suggest that ECoG could be a more stable and less invasive alternative to intracortical electrodes for BCI systems, and could also prove useful in studies of motor function.

The role of sexual and asexual reproduction in structuring high latitude populations of the reef coral Pocillopora damicornis

The genotypic composition of populations of the asexually viviparous coral Pocillopora damicornis varies in a manner that challenges classical models of the roles of sexual and asexual reproduction. On the geographically isolated Hawaiian reefs and high latitude reefs in Western Australia, P. damicornis populations are highly clonal although it has been argued that sexual reproduction via broadcast spawning generates widely dispersed colonists. In contrast, on eastern Australia's tropical Great Barrier Reef populations show little evidence of clonality. Here, we compare the genotypic diversity of adult and juvenile colonies of P. damicornis at seven sites on eastern Australia's high latitude Lord Howe Island reefs to determine if levels of clonality vary with habitat heterogeneity and age of colonies (as predicted by theory) or alternatively if clonality is again always high as for other isolated reef systems. We found 55-100% of the genotypic diversity expected for random mating at all seven sites and little evidence of asexual recruitment irrespective of habitat heterogeneity (sheltered versus wave exposed) or colony age. We found reduced levels of genetic diversity compared with tropical reefs (2.75 versus 4 alleles/locus), which supports earlier findings that Lord Howe Island is an isolated reef system. Furthermore, heterozygote deficits coupled with significant genetic subdivision among sites (FST=0.102+/-0.03) is typical of populations that have limited larval connections and are inbred. We conclude that the genetic structure of P. damicornis at Lord Howe Island reflects populations that are maintained through localised recruitment of sexually produced larvae.

Recovery of standing balance and functional mobility after stroke11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated

OBJECTIVE

To examine the extent to which recovery of functional balance and mobility is accompanied by change in a few specific physiologic measures of postural control.

DESIGN

Longitudinal prospective study.

SETTING

Laboratory setting in Ontario.

PARTICIPANTS

Twenty-seven volunteers (age, 64.2+/-13.7y) undergoing 4 weeks of rehabilitation after stroke participated. At initial testing, patients were 32.7+/-18.4 days poststroke and exhibited a moderate level of motor recovery (lower-extremity and postural control, stages 3-4 on the Chedoke-McMaster Stroke Assessment Impairment Inventory).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Three functional measures (Berg Balance Scale, Clinical Outcome Variables Scale, gait speed) were assessed. Three physiologic measures (electromyographic data of hamstrings and soleus muscles bilaterally, postural sway, arm acceleration) were taken while subjects stood quietly on a force platform and while they performed a rapid shoulder flexion movement of the nonparetic upper extremity.

RESULTS

After 1 month of rehabilitation, there was an overall significant improvement in all outcome measures (functional, physiologic). However, 10 patients failed to show any improvement in the electromyographic activation of hamstrings muscle on the paretic side in response to the rapid arm movement. These patients compensated by increasing the anticipatory activation of the nonparetic hamstrings.

CONCLUSION

After stroke, patients showed improvement in both physiologic and functional measures of balance and mobility over a 1-month period. We have identified some patients who may be using compensatory strategies to increase function. The factors that may predict those patients who are likely to use compensatory strategies awaits further study.