Ailie Turton

Grasp Size and Accuracy of Approach in Reaching

In reaching for an object in the environment, it has been suggested that movement components concerned with transport of the hand toward the object and those related to grasping the object are organized and executed independently. An experiment is reported that demonstrates people adjust grasp aperture to compensate for factors affecting transport error. Grasp aperture was found to be greater in reaching movements performed faster than normal, and grasp aperture was also found to be wider when reaching with the eyes closed. In both cases, transport was spatially less accurate. It is argued that, in advance of movement, formation of grasp is planned to take into account not only the perceived characteristics of the object but, also, internalized information based on past experience about the likely accuracy of the transport component.

A single blinded randomised controlled pilot trial of prism adaptation for improving self-care in stroke patients with neglect

Prism adaptation has been shown to alleviate the symptoms of unilateral spatial neglect following stroke in single case and small group studies. The purposes of this single blinded pilot randomised controlled trial were to determine the feasibility of delivering prism adaptation treatment in a clinically valid sample and to assess its impact on self-care. Thirty seven right hemisphere stroke patients with unilateral spatial neglect were randomised into either prism adaptation (using 10 dioptre, 6 degree prisms) or sham treatment (using plain glasses) groups. Treatment was delivered each weekday for two weeks. Pointing accuracy, without vision of the finger, was recorded each day before treatment. Outcome was measured, by blinded assessors, four days and eight weeks after the end of treatment using the Catherine Bergego Scale (CBS) and the conventional neuropsychological tests from the Behavioural Inattention Test (BIT). Thirty four patients received treatment: 16 with prisms, 18 sham. Mean compliance was 99% and 97%, respectively. Over the treatment days only the prism treated group showed increased leftward bias in open loop pointing to targets on a touch screen. However, despite the group level changes in pointing behaviour no overall effect of the treatment on self-care or BIT were found.

A pilot randomized controlled trial of a daily muscle stretch regime to prevent contractures in the arm after stroke

Objective: To evaluate the feasibility and effects of daily stretch positioning for prevention of contractures in stroke patients without arm function. Design: Randomized controlled pilot study. Setting: Stroke rehabilitation ward, UK. Subjects: Twenty-five subjects drawn from an initial pool of 126 presenting with loss of arm function, all within four weeks of stroke. Interventions: In addition to usual care, subjects in the experimental group (n =13) were prescribed two 30-min stretches for wrist and finger flexors and two 30-min stretches targeting shoulder adductors and internal rotators, per day for up to 12 weeks post stroke. Stretches were carried out by therapists and nursing staff. Main measures: Passive range of wrist extension and shoulder external rotation to standard force or to pain at four, eight and twelve weeks after stroke. Results: Compliance was variable. Frequency of positioning was fair from four to eight weeks post stroke but declined after that. Mean (SD) frequency of stretch positions completed between four and eight weeks was 36.5 (13.0) for the wrist, 31.2 (14.1) for the shoulder, out of 56 prescribed. There were no significant effects of treatment. By eight weeks post stroke the mean range of wrist extension and shoulder external rotation lost on the affected side in both groups was 30 degrees. Conclusions: The stretch treatment was not well tolerated over many weeks. Statistical power was low due to the large degree of variability of range of motion and small sample size. The regime tested cannot be recommended as a workable treatment to prevent contractures.

A test battery to measure the recovery of voluntary movement control following stroke

Tests of upper limb function and an activities of daily living (ADL) index were selected to measure recovery following stroke. Thirty stroke patients were assessed at intervals for up to 6 months to 1 year post-stroke using the battery. The results showed the ADL index is insensitive to upper limb recovery. All the tests measured recovery in some of the patients after 24 weeks post-stroke. Since the presentation and recovery of patients was variable, it is argued that it is necessary to offer a selection of assessment tests to measure recovery and to aid treatment planning.

Home-based reach-to-grasp training for people after stroke: study protocol for a feasibility randomized controlled trial

BackgroundThis feasibility study is intended to assess the acceptability of home-based task-specific reach-to-grasp (RTG) training for people with stroke, and to gather data to inform recruitment, retention, and sample size for a definitive randomized controlled trial.Methods/designThis is to be a randomized controlled feasibility trial recruiting 50 individuals with upper-limb motor impairment after stroke. Participants will be recruited after discharge from hospital and up to 12 months post-stroke from hospital stroke services and community therapy-provider services. Participants will be assessed at baseline, and then electronically randomized and allocated to group by minimization, based on the time post-stroke and extent of upper-limb impairment. The intervention group will receive 14 training sessions, each 1 hour long, with a physiotherapist over 6 weeks and will be encouraged to practice independently for 1 hour/day to give a total of 56 hours of training time per participant. Participants allocated to the control group will receive arm therapy in accordance with usual care. Participants will be measured at 7 weeks post-randomization, and followed-up at 3 and 6 months post-randomization. Primary outcome measures for assessment of arm function are the Action Research Arm Test (ARAT) and Wolf Motor Function Test (WMFT). Secondary measures are the Motor Activity Log, Stroke Impact Scale, Carer Strain Index, and health and social care resource use. All assessments will be conducted by a trained assessor blinded to treatment allocation. Recruitment, adherence, withdrawals, adverse events (AEs), and completeness of data will be recorded and reported.DiscussionThis study will determine the acceptability of the intervention, the characteristics of the population recruited, recruitment and retention rates, descriptive statistics of outcomes, and incidence of AEs. It will provide the information needed for planning a definitive trial to test home-based RTG training.Trial registrationISRCTN: ISRCTN56716589

The Development of the Cambridge Apraxia Battery

This paper describes an attempt to develop a battery of tests for use when assessing stroke patients for the presence of apraxia. The authors had found that existing studies of apraxia produced little information that was of practical use to therapists. Using an information-processing approach, the present study provides a test battery that yields useful information to a therapist treating patients with apraxia. Construction of the test battery is described, followed by a discussion of the application of the information gained from administering the battery to 27 stroke patients.

A multiple case design experiment to investigate the performance and neural effects of a programme for training hand function after stroke

Objective: To investigate the effects of task-specific practice on hand function in stroke subjects who were given computer-assisted training and to look for associated changes in corticospinal connectivity. Design: Single case design experiments. Setting: Subjects’ homes. Subjects: Seven chronic stroke subjects with impaired hand function. Interventions: Daily intensive practice of fast and accurate force changes in pinch grip and knob turning grip for four weeks. Main measures: Pinch and power grip strength and dexterity measured using the Ten-hole Peg Test and a timed nuts and bolts test were recorded twice a week throughout the study. Corticospinal connectivity was assessed by latency of electromyography (EMG) responses to transcranial magnetic stimulation (TMS) recorded during the baseline weeks before the training and again immediately after the training period. Results: Subjects completed between 5760 and 18 560 force changes. Clinically relevant improvements in grip strength were evident in only two subjects. None of the subjects showed clinically significant improvement in dexterity measures. Statistical analysis showed that improved performance was related to the training phase in only two subjects. A reduction in latency of EMG responses to TMS was seen in two subjects but could not be attributed to the training phase. Conclusions: The intensive training did not improve hand function in most subjects. Latencies of EMG responses to TMS were also unable to detect any change.

Mechanisms for Recovery of Hand and Arm Function after Stroke: A Review of Evidence from Studies Using Non-Invasive Investigative Techniques

The mechanisms for recovery of motor function after stroke are largely unknown. New non-invasive techniques of Positron Emission Tomography (PET) and Transcranial Magnetic Stimulation (TMS) have provided evidence for changes within the cortical motor areas and descending pathways after stroke in adult subjects. Reorganisation of the corticospinal tract originating from the damaged hemisphere is important for recovery of hand function. Some implications for occupational therapy are discussed.

Regulation of lateral position of body centre of mass in standing balance

On average, normal adults stand with a nearly symmetric distribution of body weight between the legs, although there is a wide range of individual differences. In the static case, the symmetric distribution of weight implies a position for the centre of body mass (CM) that would maximise stability in the face of random, laterally directed, disequilibrating forces. It therefore seems reasonable to hypothesise that people regulate CM position.In a new experiment with 204 normal adult subjects, we examined the change in weight distribution on raising an arm out to the side. Compared to standing symmetrically, arms by the side, holding one arm out resulted in a statistically reliable change in weight distribution. However, the change was significantly less than would be predicted from the uncompensated postural effect on CM of one arm being raised. This finding supports the hypothesis of CM position regulation. We suggest that in the training of standing balance, the traditional emphasis on an even distributi...

The use of a simple aiming task to measure recovery following stroke

Recovery following stroke is commonly measured in terms of activities of daily living. However, a measure of the return of movement control and co-ordination is also needed. The criteria to be considered when designing such a test are discussed.A simple test of upper limb function, based on the task used by Fitts and Peterson, is described. The results of administering this test to patients following cerebrovascular accident are discussed in relation to movement control theory.