The assessment of posture and balance post-stroke

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Physiotherapy for people with stroke has been found to be beneficial but details of the most effective interventions are unclear. Further development of the evidence base for stroke physiotherapy is limited by a lack of clinical practice models, sensitive clinically based outcome measures and effective stratification techniques to characterise homogenous groups of subjects. These issues are addressed here with regard to balance and posture. These aspects were chosen because they form a cornerstone of stroke physiotherapy as they are thought essential for the rehabilitation of functional activities. A systematic review of assessment methods in the literature revealed a lack of measurement tools which met the utility criteria: reliability, validity, sensitivity to short-term change, suitability for a wide range of abilities, ease of use and suitability for different settings. This prompted the development of a new measurement tool. Firstly, a model of the clinical assessment process was developed using an adapted focus group method with neurological physiotherapists. This informed the content of a new measurement tool which combined an ordinal scale with functional performance tests- the Brunel Balance Assessment. The tool was evaluated in a series of studies involving 92 stroke patients. It was hierarchical (coefficient of reproducibility= 0.99, coefficient of scalability = 0.69), reliable (100% agreement) and valid as a measure of balance disability (r=0.58-0.97). The psychometric properties of the individual functional performance tests were also tested and found to be reliable (ICCs =0.88-1) and valid (r=0.32-0.63). Measurement error ranged 0-40% and the minimum change needed to detect true clinical change was calculated for each test. Balance disability, measured with the Brunel Balance Assessment, is heterogeneous with sitting, standing and stepping balance forming distinct levels of ability (p<0.027). Consequently, the BBA could be used to stratify people with stroke according to balance ability. Weakness, sensation and age were significant independent contributors to balance disability (r2=82.7%). Balance ability was a strong contributor to independence in ADL (p<0.0001). The findings of this thesis address the issues that have limited research into stroke physiotherapy with regard to balance disability. In relation to clinical practice, a robust measurement and stratification tool has been developed.Department of Health Studies, Brunel University and the Brunel University Research Enterpris

How to measure fatigue in neurological conditions? A systematic review of psychometric properties and clinical utility of measures used so far

Objective: To systemically review the psychometric properties and clinical utility (feasibility) of tools to measure fatigue in neurological conditions. Data sources: AMED, CINAHL, MEDLINE, Science Direct and Web of Knowledge were searched for studies of the psychometric properties of fatigue measures in adults with central nervous system disorders. Search terms were: Fatigue AND assess* OR measure* OR tool OR outcome OR index OR test OR scale AND stroke OR cerebrovascular* OR hemi* OR parkinson* OR sclerosis OR head injury OR brain injury OR motor neurone disease OR neuro* Review methods: Articles that addressed validity; reliability and ability to detect change were selected. Two authors independently selected articles and extracted data. Strength of the psychometric properties and clinical utility were assessed against predetermined thresholds. Results: A total of 25 articles were selected and 17 measurement tools identified including six versions of the Fatigue Severity Scale and five versions of the Fatigue Impact Scale. All were clinically feasible but none met all the criteria. Most were valid. Reliability and ability to detect change were infrequently evaluated, but were adequate when reported. The most thoroughly developed and psychometrically robust measures were the Neurological Fatigue Indices. Conclusion: Although many measures of fatigue in neurological conditions have published, none met all of the criteria for psychometric robustness and clinical utility but the Neurological Fatigue Indices are the best and can be used with caution </jats:sec

Service users' views of the assessment process in stroke rehabilitation

Objective: To investigate the service users’ (stroke survivors and care-givers) experiences and views of the rehabilitation assessment process. Design: Qualitative data analysis from three focus groups using a content analysis to identify the major themes. Setting: Participants were recruited from stroke support groups and community rehabilitation services in a large UK city. Subjects: Seventeen community-dwelling stroke survivors who had completed their rehabilitation within the previous year and six care-givers. Results: Five themes emerged: understanding the purpose of the assessment; repetition of assessments; feedback about assessments and progress; format of feedback and barriers to feedback. While all participants reported undergoing assessment, some felt their purpose was not always explained and resented unexplained repetitions of tests. Some participants reported a positive experience, but most wanted more information about their progress and predictions of recovery. They wanted regular, consistent, objective information presented in layman’s terms; verbally and in writing. Some carers reported difficulty accessing information particularly as a result of confidentiality policies. While some participants accepted these short-comings, others considered them due to staff’s disinterest or ineptitude, which undermined their trust in the team. Conclusions: Stroke service users require clear information about the purpose of assessments and regular, consistent, objective feedback about their progress using layman’s language both verbally and in writing. </jats:sec

The effect of stroke on foot kinematics and the functional consequences

Background Although approximately one-third of stroke survivors suffer abnormal foot posture and this can influence mobility, there is very little objective information regarding the foot and ankle after stroke. Objective As part of a programme of research examining foot and ankle biomechanics after stroke, we investigated multi-planar kinematics and the relationship with function. Methods In a single assessment session, static foot posture (Foot Posture Index); mobility limitations (Walking Handicap Scale) and multi-segment foot and ankle kinematics during stance phase of walking were measured in 20 mobile chronic stroke survivors and 15 sex and age-matched healthy volunteers. Results Compared to the healthy volunteers, the stroke survivors demonstrated consistently reduced range of motion across most segments and planes, increased pronation and reduced supination, disruption of the rocker and the timing of joint motion. Changes in pronation/supination were associated with limited walking ability. Conclusions This study provides evidence of structural and movement deficiencies in the intrinsic foot segments affected by stroke. These would not have been detectable using a single segment foot model. Data do not support common clinical practices that focus on correction of sagittal ankle deformity and assumed excessive foot supination. Some of these abnormalities were associated with limitation in functional ability. Biomechanical abnormalities of foot and ankle are modifiable and there is potential for clinical studies and future developments of interventions to help prevent or treat these abnormalities which may improve functional ability post stroke

Sensorimotor delays in tracking may be compensated by negative feedback control of motion-extrapolated position.

Funder: University of CambridgeSensorimotor delays dictate that humans act on outdated perceptual information. As a result, continuous manual tracking of an unpredictable target incurs significant response delays. However, no such delays are observed for repeating targets such as the sinusoids. Findings of this kind have led researchers to claim that the nervous system constructs predictive, probabilistic models of the world. However, a more parsimonious explanation is that visual perception of a moving target position is systematically biased by its velocity. The resultant extrapolated position could be compared with the cursor position and the difference canceled by negative feedback control, compensating sensorimotor delays. The current study tested whether a position extrapolation model fit human tracking of sinusoid (predictable) and pseudorandom (less predictable) targets better than the non-biased position control model, Twenty-eight participants tracked these targets and the two computational models were fit to the data at 60 fixed loop delay values (simulating sensorimotor delays). We observed that pseudorandom targets were tracked with a significantly greater phase delay than sinusoid targets. For sinusoid targets, the position extrapolation model simulated tracking results more accurately for loop delays longer than 120 ms, thereby confirming its ability to compensate for sensorimotor delays. However, for pseudorandom targets, this advantage arose only after 300 ms, indicating that velocity information is unlikely to be exploited in this way during the tracking of less predictable targets. We conclude that negative feedback control of position is a parsimonious model for tracking pseudorandom targets and that negative feedback control of extrapolated position is a parsimonious model for tracking sinusoidal targets

The effect of stroke on foot biomechanics; underlying mechanisms and the functional consequences

Although approximately one-third of stroke survivors suffer abnormal foot posture and this can influence mobility [1], there is very little objective information regarding the foot and ankle after stroke

Delivery, dose, outcomes and resource use of stroke therapy: the SSNAPIEST observational study

BackgroundTherapy is key to effective stroke care, but many patients receive little.ObjectivesTo understand how stroke therapy is delivered in England, Wales and Northern Ireland, and which factors are associated with dose, outcome and resource use.DesignSecondary analysis of the Sentinel Stroke National Audit Programme, using standard descriptive statistics and multilevel mixed-effects regression models, while adjusting for all known and measured confounders.SettingStroke services in England, Wales and Northern Ireland.ParticipantsA total of 94,905 adults admitted with stroke, who remained an inpatient for > 72 hours.ResultsRoutes through stroke services were highly varied (> 800), but four common stroke pathways emerged. Seven distinct impairment-based patient subgroups were characterised. The average amount of therapy was very low. Modifiable factors associated with the average amount of inpatient therapy were type of stroke team, timely therapy assessments, staffing levels and model of therapy provision. More (of any type of) therapy was associated with shorter length of stay, less resource use and lower mortality. More occupational therapy, speech therapy and psychology were also associated with less disability and institutionalisation. Large amounts of physiotherapy were associated with greater disability and institutionalisation.LimitationsUse of observational data does not infer causation. All efforts were made to adjust for all known and measured confounding factors but some may remain. We categorised participants using the National Institutes of Health Stroke Scale, which measures a limited number of impairments relatively crudely, so mild or rare impairments may have been missed.ConclusionsStroke patients receive very little therapy. Modifiable organisational factors associated with greater amounts of therapy were identified, and positive associations between amount of therapy and outcome were confirmed. The reason for the unexpected associations between large amounts of physiotherapy, disability and institutionalisation is unknown. Prospective work is urgently needed to investigate further. Future work needs to investigate (1) prospectively, the association between physiotherapy and outcome; (2) the optimal amount of therapy to provide for different patient groups; (3) the most effective way of organising stroke therapy/rehabilitation services, including service configuration, staffing levels and working hours; and (4) how to reduce unexplained variation in resource use.FundingThis project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 8, No. 17. See the NIHR Journals Library website for further project information

Case Series of a Knowledge Translation Intervention to Increase Upper Limb Exercise in Stroke Rehabilitation

Background and Purpose. Current approaches to upper limb rehabilitation are not sufficient to drive neural reorganization and maximize recovery after stroke. To address this evidence-practice gap, a knowledge translation intervention using the Behaviour Change Wheel was developed. The intervention involves collaboratively working with stroke therapy teams to change their practice and increase therapy intensity by therapists prescribing supplementary self-directed arm exercise. The purposes of this case series are: (1) to provide an illustrative example of how a research-informed process changed clinical practice and (2) to report on staff members’ and patients’ perceptions of the utility of the developed intervention. Case Descriptions. A participatory action research approach was used in 3 stroke rehabilitation units in the United Kingdom. The intervention aimed to change 4 therapist-level behaviors: (1) screening patients for suitability for supplementary self-directed arm exercise, (2) provision of exercises, (3) involving family and caregivers in assisting with exercises, and (4) monitoring and progressing exercises. Data on changes in practice were collected by therapy teams using a bespoke audit tool. Utility of the intervention was explored in qualitative interviews with patients and staff. Outcomes. Components of the intervention were successfully embedded in 2 of the 3 stroke units. At these sites, almost all admitted patients were screened for suitability for supplementary self-directed exercise. Exercises were provided to 77%, 70%, and 88% of suitable patients across the 3 sites. Involving family and care givers and monitoring and progressing exercises were not performed consistently. Conclusions. This case report is an example of how a rigorous research-informed knowledge translation process resulted in practice change. Research is needed to demonstrate that these changes can translate into increased intensity of upper limb exercise and affect patient outcome