Attentional focus of feedback for improving performance of reach-to-grasp after stroke: a randomised crossover study

Attentional focus effects on joint covariation in a reaching task

Adopting an external focus of attention (EF) has been found beneficial over internal focus (IF) for performing motor skills. Previous studies primarily examined focus of attention (FOA) effects on performance outcomes (such as error and accuracy), with relatively less emphasis on movement coordination. Given that human movements are kinematically and kinetically abundant (Gefland & Latash, 1998), FOA instructions may change how motor abundance is utilized by the CNS. This study applied the uncontrolled manifold analysis (UCM) to address this question in a reaching task. Healthy young adults (N = 38; 22 ± 1 yr; 7 men, 31 women) performed planar reaching movements to a target using either the dominant or nondominant arm under two different FOA instructions: EF and IF. Reaching was performed without online visual feedback and at a preferred pace. Joint angles of the clavicle-scapula, shoulder, elbow, and wrist were recorded, and their covariation for controlling dowel endpoint position was analyzed via UCM. As expected, IF led to a higher mean radial error than EF, driven by increases in aiming bias and variability. Consistent with this result, the UCM analysis showed that IF led to higher goal-relevant variance among the joints (V_ORT) compared to EF starting from the first 20% of the reach to the end. However, the goal-irrelevant variance (V_UCM)-index of joint variance that does not affect the end-effector position-did not show FOA effects. The index of stability of joint coordination with respect to endpoint position (ΔV) was also not different between the EF and IF. Consistent with the constrained action hypothesis, these results provide evidence that IF disrupted goal-relevant joint covariation starting in the early phases of the reach without affecting goal-irrelevant coordination.

External and internal focus of attention differentially modulate corticospinal excitability in anticipatory postural adjustments

Whether attentional focus modulates the corticospinal excitability of the lower limb muscles in anticipatory postural adjustments (APAs) when performing a ballistic movement of the upper limb remains unclear. The present study used transcranial magnetic stimulation (TMS) to examine the corticospinal excitability of the lower limb muscles along with the kinematic profiles during dart throwing with different attentional foci, external focus (EF) and internal focus (IF). In 13 healthy participants, TMS was applied immediately before electromyographic onset of the tibialis anterior (TA) muscle, and the motor evoked potential (MEP) was recorded in the TA and soleus (SOL) muscles. The performance accuracy was significantly higher in the EF condition than in the IF condition. In both EF and IF conditions, MEP amplitude in the TA muscle, but not the SOL muscle, was significantly higher immediately before TA muscle onset (- 100, - 50, and 0 ms) compared to the control. In particular, the MEP increment in the TA muscle before TA muscle onset (- 50 and 0 ms) was significantly larger in the EF condition than in the IF condition. Our findings provide the first evidence for the modulation of corticospinal excitability in APA by changing attentional focus.

A novel sensor-embedded holding device for monitoring upper extremity functions

There are several causes that can lead to functional weakness in the hands or upper extremities (UE), such as stroke, trauma, or aging. Therefore, evaluation and monitoring of UE rehabilitation have become essential. However, most traditional evaluation tools (TETs) and assessments require clinicians to assist or are limited to specific clinical settings. Several novel assessments might apply to wearable devices, yet those devices will still need clinicians or caretakers to help with further tests. Thus, a novel UE assessment device that is user-friendly and requires minimal assistance would be needed. The cylindrical grasp is one of the common UE movements performed in daily life. Therefore, a cylindrical sensor-embedded holding device (SEHD) for training and monitoring was developed for a usability test within this research. The SEHD has 14 force sensors with an array designed to fit holding positions and a six-axis inertial measurement unit (IMU) to monitor grip strength, hand dexterity, acceleration, and angular velocity. Six young adults, six healthy elderly participants, and three stroke survivors had participated in this study to see if the SEHD could be used as a reference to TETs. During result analyses, where the correlation coefficient analyses were applied, forearm rotation smoothness and the Purdue Pegboard Test (PPT) showed a moderate negative correlation [r (16) = −0.724, p < 0.01], and the finger independence showed a moderate negative correlation with the PPT [r (10) = −0.615, p < 0.05]. There was also a highly positive correlation between the maximum pressing task and Jamar dynamometer in maximum grip strength [r (16) = 0.821, p < 0.01]. These outcomes suggest that the SEHD with simple movements could be applied as a reference for users to monitor their UE ability.

Direction of attentional focus in prosthetic training: Current practice and potential for improving motor learning in individuals with lower limb loss

Objective

Adopting an external focus of attention has been shown to benefit motor performance and learning. However, the potential of optimizing attentional focus for improving prosthetic motor skills in lower limb prosthesis (LLP) users has not been examined. In this study, we investigated the frequency and direction of attentional focus embedded in the verbal instructions in a clinical prosthetic training setting.

Methods

Twenty-one adult LLP users (8 female, 13 male; 85% at K3 level; mean age = 50.5) were recruited from prosthetic clinics in the Southern Nevada region. Verbal interactions between LLP users and their prosthetists (mean experience = 10 years, range = 4–21 years) during prosthetic training were recorded. Recordings were analyzed to categorize the direction of attentional focus embedded in the instructional and feedback statements as internal, external, mixed, or unfocused. We also explored whether LLP users’ age, time since amputation, and perceived mobility were associated with the proportion of attentional focus statements they received.

Results

We recorded a total of 20 training sessions, yielding 904 statements of instruction from 338 minutes of training. Overall, one verbal interaction occurred every 22.1 seconds. Among the statements, 64% were internal, 9% external, 3% mixed, and 25% unfocused. Regression analysis revealed that female, older, and higher functioning LLP users were significantly more likely to receive internally-focused instructions (p = 0.006, 0.035, and 0.024, respectively).

Conclusions

Our results demonstrated that verbal instructions and feedback are frequently provided to LLP users during prosthetic training. Most verbal interactions are focused internally on the LLP users’ body movements and not externally on the movement effects.

Impact statement

While more research is needed to explore how motor learning principles may be applied to improve LLP user outcomes, clinicians should consider adopting the best available scientific evidence during treatment. Overreliance on internally-focused instructions as observed in the current study may hinder prosthetic skill learning.

Characterization of stroke-related upper limb motor impairments across various upper limb activities by use of kinematic core set measures

Background

Upper limb kinematic assessments provide quantifiable information on qualitative movement behavior and limitations after stroke. A comprehensive characterization of spatiotemporal kinematics of stroke subjects during upper limb daily living activities is lacking. Herein, kinematic expressions were investigated with respect to different movement types and impairment levels for the entire task as well as for motion subphases.

Method

Chronic stroke subjects with upper limb movement impairments and healthy subjects performed a set of daily living activities including gesture and grasp movements. Kinematic measures of trunk displacement, shoulder flexion/extension, shoulder abduction/adduction, elbow flexion/extension, forearm pronation/supination, wrist flexion/extension, movement time, hand peak velocity, number of velocity peaks (NVP), and spectral arc length (SPARC) were extracted for the whole movement as well as the subphases of reaching distally and proximally. The effects of the factors gesture versus grasp movements, and the impairment level on the kinematics of the whole task were tested. Similarities considering the metrics expressions and relations were investigated for the subphases of reaching proximally and distally between tasks and subgroups.

Results

Data of 26 stroke and 5 healthy subjects were included. Gesture and grasp movements were differently expressed across subjects. Gestures were performed with larger shoulder motions besides higher peak velocity. Grasp movements were expressed by larger trunk, forearm, and wrist motions. Trunk displacement, movement time, and NVP increased and shoulder flexion/extension decreased significantly with increased impairment level. Across tasks, phases of reaching distally were comparable in terms of trunk displacement, shoulder motions and peak velocity, while reaching proximally showed comparable expressions in trunk motions. Consistent metric relations during reaching distally were found between shoulder flexion/extension, elbow flexion/extension, peak velocity, and between movement time, NVP, and SPARC. Reaching proximally revealed reproducible correlations between forearm pronation/supination and wrist flexion/extension, movement time and NVP.

Conclusion

Spatiotemporal differences between gestures versus grasp movements and between different impairment levels were confirmed. The consistencies of metric expressions during movement subphases across tasks can be useful for linking kinematic assessment standards and daily living measures in future research and performing task and study comparisons.

Trial registration: ClinicalTrials.gov Identifier NCT03135093. Registered 26 April 2017, https://clinicaltrials.gov/ct2/show/NCT03135093.

The difference in attentional focus during exercise affects attention resources

[Purpose] The purpose of this study was to investigate the effect of the difference in attentional focus, including the external focus (EF) or internal focus (IF) during exercise on attention resources from the viewpoint of the brain activity. [Participants and Methods] The study included 20 healthy adult participants randomly assigned to two groups: the EF and IF groups. The participants in each group received different verbal instructions before performing a tennis ball task, in which they threw a tennis ball on the floor at a target with their non-dominant hands as accurately as possible while sitting on a chair. During the task, oxygenated hemoglobin (oxy-Hb) in the right dorsolateral prefrontal cortex was continuously measured using a near-infrared spectroscopy device. The accuracy of the task and the change of oxy-Hb were statistically analyzed. [Results] Although there were no statistically significant differences between the groups, both accuracy of the task and oxy-Hb in the EF group were found to be higher than those in the IF group. [Conclusion] Our results showed that although the accuracy of motor control in the EF was superior to that in the IF, there is a possibility of increased attention resources in the EF compared to those in the IF.

Development of lower limb training interventions that promote an external focus of attention in people with stroke: a modified Delphi survey

Objective

To produce guidance and validated examples of tasks that promote an external focus of attention, for use in lower limb rehabilitation in an inpatient stroke care setting.

Design

Electronic survey, using e-Delphi methodology.

Participants

A multi-professional expert panel of 14 clinicians and researchers, with expertise in stroke rehabilitation and/or motor learning.

Method

Each survey round consisted of two parts: 1) classification of specific exercise examples, shown using video and 2) the categorization of specific tratement adjuncts. The panel was asked to comment on: likely focus of attention of the performer; instructions that would promote an external focus of attention; and how the task set-up could be modified to promote an external focus of attention. Rounds 2 and 3 included a summary of results from the previous round, and revised/new examples. The panel were also asked to state their level of agreement with a series of statements that arose from the free text. Three rounds of survey were completed and the a priori threshold for agreement was set at 80%.

Results

Eighteen iterations of exercises were presented, and 12 were accepted as promoting an external focus of attention. In addition, six additional statements were generated based on open responses, leading to further specific guidance on facilitating an external focus of attention in clinical practice.

Conclusions

Commonly used rehabilitation exercises can be adapted to promote an external focus of attention, by altering the therapist’s use of instructions and/or altering the task set up. Treatment principles and examples of tasks that promote an external focus have been produced.

Overload of anxiety on postural control impairments in chronic stroke survivors: The role of external focus and cognitive task on the automaticity of postural control

Background

Despite the high prevalence of anxiety among chronic stroke survivors and evidence of its negative effects on postural control in healthy subjects, it is unclear whether anxiety also affects postural control in these patients. Recent evidence of improved postural control of healthy subjects by distracting the attention using an external focus (EF) or cognitive task, raises the question of whether similar benefits would be observed in stroke survivors. Thus, the current study aimed to investigate the effects of anxiety and distracting the attention on postural control of chronic stroke survivors in terms of both postural sway measures and neuromuscular regulation.

Methods

Postural sway measures and ankle muscle activity of chronic stroke survivors with the high and low level of anxiety (HA-stroke (n = 17), and LA-stroke (n = 17), respectively) and age-, sex-, height-, and weight-matched healthy subjects (n = 17) were assessed while standing on rigid and foam surfaces under following conditions: baseline, internal focus (IF), EF, simple and hard cognitive tasks (SC and HC, respectively).

Results

Stroke survivors, particularly HA-stroke participants, showed greater postural sway measures (i.e. postural instability) and enhanced co-contraction of ankle muscles (i.e. stiffening of the neuromuscular system) compared with healthy subjects. As opposed to baseline and IF conditions, postural instability and neuromuscular stiffening significantly reduced in EF condition and decreased more in cognitive task conditions, particularly HC condition.

Conclusions

The results suggest that anxiety enhances stroke-induced postural instability promoting improper neuromuscular control of posture with stiffening strategy, which can be alleviated by EF and cognitive tasks.

The effect of frequency of feedback on overground temporal gait asymmetry post stroke

BACKGROUND AND OBJECTIVES

Temporal gait asymmetry (TGA) affects 55% of people with stroke. This study investigated the effects of augmented feedback during overground gait training, on TGA.

METHODS

Eighteen people with chronic stroke were randomized to receive one of two feedback displays (A or B) and one of three feedback frequencies; no feedback (0%), after alternate walking trials (50%) or after every trial (100%). Display A depicted the TGA ratio as a vertical line along a horizontal axis with perfect symmetry in the middle. Display B depicted single limb stance duration of each leg as a bar graph. Participants completed 25 repetitions of 30 second trials with their assigned feedback (acquisition). Participants completed 10 repetitions of 30 second trials without feedback 24 hours later (retention). A pressure sensitive mat recorded TGA and speed. Changes in TGA and speed were investigated by plotting individual motor learning curves and fitting a curve with locally estimated scatterplot smoothing (LOESS) for each feedback group. An effect of feedback was defined a priori as a LOESS fitted curve with a decreasing slope from acquisition to retention.

RESULTS

LOESS curve exhibited a decreasing slope for TGA in the 100B group only and for speed in the 50A and 0FB groups.

DISCUSSION

This study provides preliminary evidence that visual feedback delivered at a high frequency during a single session of overground walking can change TGA post-stroke without reducing gait speed. An overground gait intervention with high frequency visual feedback to improve TGA post-stroke is worthwhile to investigate.

Effects of attentional focus on upper extremity motor performance in post stroke patients: A randomized pilot study

INTRODUCTION

To facilitate the command to the learner, therapist can use verbal cues for guidance: internal focus (own body) and external focus (consequence of movement in the environment).

OBJECTIVE

To examine the effects of different attentional focus on upper limb motor performance in post-stroke.

METHODS

Randomized controlled trial with 2 groups. Study realized at Integrated Clinic of the Faculty of Health Science at Trairi (Santa Cruz, Rio Grande do Norte, Brazil). Twelve participants allocated into 2 groups. Two motor tasks were used: task 1, reach-point; task 2, reach-grasp-fit, with the paretic extremity, using verbal commands directed by a trained therapist. In the first phase, Group 1 received commands with internal focus, while Group 2 was instructed with commands with external focus. After 1 week, the command type was changed between groups. The variables collected was movement time, velocity and number of peaks velocity.

RESULTS

Both attentional focus promoted significant differences in movement time and velocity, however, only Internal Focus provided significant results in both tasks of the same variables.

DISCUSSION

The benefits of 1 attentional focus on the other are not fully confirmed. However, not receiving any kind of attention guidance compromises motor performance. The results support the hypothesis that the benefits of the External Focus are accentuated when preceded by the Internal Focus.

CLINICAL TRIAL REGISTRATION

Research Ethics Committee of the Faculty of Helth Science at Trairi (Facisa - UFRN)- Number CAAE 2.625.609, approved on April 13, 2018; Brazilian Registry of Clinical Trials - RBR-4995cr approved on July 4, 2019 retrospectively registered (http://www.ensaiosclinicos.gov.br/rg/RBR-4995cr/).

An external focus of attention compared to an internal focus of attention improves anticipatory postural adjustments among people post-stroke

BACKGROUND

People after stroke often have postural impairments that can increase their risk of falling. Anticipatory postural adjustments (APAs) are changes in the activity of postural muscles prior to a voluntary movement in order to maintain vertical equilibrium. Previous research suggests that improving APAs leads to better postural control and reduces the risk of falls. Despite the importance of APAs and their impairment among people post-stroke, studies that aim to investigate methods for improving APAs are limited. Consistent evidence supports that an external focus of attention compared to an internal focus of attention, yields superior performance of motor skills that include postural control.

RESEARCH QUESTION

What are the effects of adopting different foci of attention on measures of APAs and movement parameters when performing a lower extremity Fitts' task among people post-stroke?

METHODS

Twelve individuals post-stroke performed a lower extremity stepping movement (Fitts' task) while adopting an external focus or an internal focus of attention in a within-subject design. A motion capture system was used to record participants' movement data. Custom software derived movement time (MT), peak velocity (PV), time to peak velocity (ttPV) and variability at endpoint (SD_T). Electromyography was used to measure muscle activity and determine APAs onset and magnitude. For all dependent variables separate repeated measures ANOVAs were conducted to compare performance between foci of attention.

RESULTS

The results showed that an external focus of attention yielded significantly better performance on all outcome measures. The improvement in performance was seen in shorter MT, higher PV, shorter ttPV, smaller SD_T, earlier APAs onset and more efficient APAs magnitude.

SIGNIFICANCE

The changes in outcome measures suggest that adopting an external focus of attention during postural tasks could be an effective strategy for improving balance control among people post-stroke.

Systematic reviews evaluating the effectiveness of motor control exercises in patients with non-specific low back pain do not consider its principles - A review

BACKGROUND

Motor control exercise (MCEs), spinal stabilization or core stability exercises were developed with the aim of restoring the coordination, control, and capacity of the trunk muscles and systematic reviews (SR) evaluating their effectiveness has shown conflicting results. This we hypothesized was due to the non-consideration of principles of neuroplasticity. The objective of this review was to review the operating definitions used in these reviews for these exercises and evaluate if these reviews have considered and satisfied the principles of these exercises in persons with NSLBP, both acute and chronic.

METHODS

The available evidence to address the research question was sought in the reviews published in English between January 2006 and April 2019 using the population, intervention, comparison, and outcome format. Data were extracted against the following factors: satisfy the principles of specific inclusion criteria; interventions; experience-dependent plasticity; and measure any one of the concepts of motor control. The quality of the evidence obtained was graded using the National Institute for Health and Care Excellence protocol and the quality of SRs evaluated using the R-AMSTAR.

RESULTS

Eleven reviews on core stability/spinal stabilization exercises and four reviews on MCE were considered in this review. The results showed that most of the studies considered by the reviews did not adhere to the principles of these exercises.

CONCLUSION

There is wide heterogeneity in the understanding, administration, and progression of exercises. The exercises were implemented without considering the potential for neuroplasticity of the nervous system and the principles of motor learning.

Comparing the Impact of an Implicit Learning Approach With Standard Care on Recovery of Mobility Following Stroke: Protocol for a Pilot Cluster Randomized Controlled Trial

BACKGROUND

Although implicit and explicit learning approaches have been well investigated in healthy populations, there is less evidence regarding the relative benefits of each approach in clinical practice. Studies in stroke typically investigate single elements of an implicit learning approach (ILA; eg, reduced quantity feedback or an external focus of attention) within controlled environments. These studies predominantly evaluate performance, with few measuring this over time (ie, learning). The relevance and transferability of current research evidence into stroke rehabilitation is therefore limited.

OBJECTIVE

The objective of this study was to compare the ILA with standard care in the acute phase following stroke, to generate data and insights to inform the design of a definitive trial, and to understand patient and therapist perceptions of the ILA.

METHODS

This is a multicenter, assessor-blind, cluster randomized controlled pilot trial with nested qualitative evaluation. Stroke units (clusters) will be randomized to either ILA (intervention) or standard care (control) arms. Therapy teams at the intervention sites will be trained in the ILA and provided with an intervention manual. Those at the control sites will have minimal input from the research team, other than for data collection. Consent will be provided at the individual participant level. Once enrolled, participants will receive rehabilitation that focuses on lower limb recovery, using the designated approach. Measures will be taken at baseline, every 2 weeks until the point of discharge from hospital, and at 3 months post stroke onset. Measures include the Fugl Meyer Assessment (motor leg subsection), modified Rivermead Mobility Index, Swedish Postural Adjustment in Stroke Scale, and achievement of mobility milestones. Fidelity of the treatment approach will be monitored using observational video analysis. Focus groups and interviews will be used to gain insight into the perceptions of trial participants and clinical teams.

RESULTS

The first site opened to recruitment in February 2019. The opening of a further 5 sites will be staggered throughout 2019. Results are expected in early 2021.

CONCLUSIONS

The findings from this mixed methods pilot study will be used to inform the design of a definitive study, comparing the ILA with standard care in acute stroke rehabilitation.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03792126; https://clinicaltrials.gov/ct2/show/NCT03792126.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/14222.

Aerobic exercise and consecutive task-specific training (AExaCTT) for upper limb recovery after stroke: A randomized controlled pilot study

OBJECTIVE

This study examined the feasibility of a parallel-group assessor-blinded randomized controlled trial investigating whether task-specific training preceded by aerobic exercise (AEX + TST) improves upper limb function more than task-specific training (TST) alone.

METHODS

People with upper limb motor dysfunction after stroke were allocated to TST or AEX + TST. Both groups were prescribed 60 hr of TST over 10 weeks (3 × 1-hr sessions with a therapist per week and 3 × 1 hr of home-based self-practice per week). The AEX + TST group performed 30 minutes of aerobic exercise immediately prior to the 1 hr of TST with the therapist. Recruitment, adherence, retention, participant acceptability, and adverse events were recorded. Clinical measures were performed prerandomization at baseline, on completion of the intervention, and at 1- and 6-month follow-up.

RESULTS

Fifty-nine persons after stroke were screened, 42 met the eligibility criteria, and 20 (11 male; mean [SD] age: 55.4 [16.0] years; time since stroke: 71.7 [91.2] months) were recruited over 17 months. The mean Wolf Motor Function Test Functional Ability Score at baseline was 27.4 (max = 75) and the mean Action Research Arm Test score was 11.2 (max = 57). Nine were randomized to AEX + TST and 11 to TST. There were no adverse events, but there was one drop out. Retention at 1- and 6-month follow-up was 80% and 85%, respectively. Attendance was 93% (6) for the AEX + TST group, and 89% (9) for the TST group. AEX + TST was perceived as acceptable (100%) and beneficial (87.5%). Exertional fatigue (visual analogue scale) prior to TST was worse in the AEX + TST group (3.5 [0.7] out of 10) than the TST group (1.7 [1.4] out of 10). The TST group performed 31% more repetitions per session than the AEX + TST group.

CONCLUSION

A subsequent Phase III study is feasible, but modifications to eligibility criteria, outcome measures, and intervention delivery are recommended.

COMbined Physical and somatoSEnsory training after stroke: Development and description of a novel intervention to improve upper limb function

BACKGROUND AND PURPOSE

After stroke, reach-to-grasp goal-directed movements are disrupted as a result of both residual motor and somatosensory impairments. This report describes the rationale and development of a new upper limb stroke rehabilitation intervention known as COMPoSE: "COMbined Physical and somatoSEnsory training," designed to improve somatosensory and motor deficits in the upper limb after stroke. A standardized training matrix has been developed to facilitate intervention delivery.

METHODS

The COMPoSE intervention was developed through the following stages: (a) Definition and operationalization of somatosensory and motor variables used in training sensation and movement after stroke; (b) development of methods to give feedback to enhance skill acquisition; and (c) Combination of somatosensory and motor variables, and feedback, into a standardized training matrix. The reporting of the COMPoSE intervention adheres to the recommendations of the Template for Intervention Description and Replication checklist to facilitate replication of the intervention in the future.

RESULTS

The essential features of COMPoSE include combined somatosensory-motor training variables (grasp pressure, distance, object size, crushability, surface texture, and friction), feedback, and calibration using a haptic device providing measures of grasp pressure, use of anticipation trials, and high-dose repetitive task practice. Ten treatment sessions are delivered over 3 weeks, using a standardized matrix for treatment delivery.

CONCLUSION

COMPoSE is a new intervention that combines somatosensory and movement training, delivered synchronously, within the same intervention, and within the same task.

Are the effects of internal focus instructions different from external focus instructions given during balance training in stroke patients? A double-blind randomized controlled trial

Objective:

This study aimed to assess if external focus instructions result in greater improvements in motor skill and automaticity compared to internal focus instructions in stroke patients.

Design:

Double-blind randomized controlled trial.

Setting:

Inpatient stroke rehabilitation unit.

Subjects:

A total of 63 stroke patients (Meanage = 59.6 ± 10.7 years; Meandays since stroke = 28.5 ± 16.6; MedianFunctional Ambulation Categories = 4).

Interventions:

Patients were randomly assigned to an internal ( N = 31) or external ( N = 32) focus instruction group. Both groups practiced a balance board stabilization task, three times per week, for three weeks. Balance performance was assessed at baseline, and after one and three weeks of practice.

Main measures:

Primary outcome was the threshold stiffness (Nm/rad) at which patients could stay balanced. Secondary outcomes were patients’ sway (root-mean-square error in degrees) at the baseline threshold stiffness under single- and dual-task conditions, and their performance on the Timed Up and Go Test and Utrecht Scale for Evaluation of Rehabilitation.

Results:

Both groups achieved similar improvements in threshold stiffness (∆= 27.1 ± 21.1 Nm/rad), and single- (∆= 1.8 ± 2.3° root-mean-square error) and dual-task sway (∆= 1.7 ± 2.1° root-mean-square error) after three weeks of practice. No differences were found in improvements in clinical tests of balance and mobility. Patients with comparatively good balance and sensory function, and low attention capacity showed greatest improvements with external focus instructions.

Conclusion:

External focus instructions did not result in greater improvement in balance skill in stroke patients compared to internal focus instructions. Results suggest that tailoring instructions to the individual stroke patient may result in optimal improvements in motor skill.

Effect of Attentional Focus Instructions on Motor Learning and Performance of Patients with Central Nervous System and Musculoskeletal Disorders: a Systematic Review

Exercise is one of the main rehabilitative interventions, commonly used to improve performance and motor learning. During the application of attentional focus strategies, External Focus of Attention (EFA) aiming at the movement effect has been reported to have more efficacy than Internal Focus of Attention (IFA) aiming at movement characteristics in healthy subjects. There are not many studies that compare the EFA and IFA instructions in people with Musculoskeletal (MSK) and Central Nervous System disorders (CNS). The purpose of this systematic review is to determine if IFA or EFA, in patients with CNS or MSK, may improve performance and have some effects on motor learning. Databases used for research: PubMed, CINAHL, Cochrane Library, PEDro, PsycINFO, SCOPUS. Inclusion criteria: Randomized Controlled Trial, quasi-Randomized Controlled Trial, enrolled subjects with CNS or with MSK and compared the efficacy of EFA and IFA. The studies suggest that the EFA is better than IFA in affecting the movement execution in patients with MSK, while conflicted findings emerge in presence of CNS disorders. Studies included in the qualitative analysis showed heterogeneous methodological features in study design and conductance, so results must be interpreted with caution.

Over-focused? The relation between patients' inclination for conscious control and single- and dual-task motor performance after stroke

BACKGROUND

Many stroke patients are inclined to consciously control their movements. This is thought to negatively affect patients' motor performance, as it disrupts movement automaticity. However, it has also been argued that conscious control may sometimes benefit motor performance, depending on the task or patientś motor or cognitive capacity.

AIM

To assess whether stroke patients' inclination for conscious control is associated with motor performance, and explore whether the putative association differs as a function of task (single- vs dual) or patientś motor and cognitive capacity.

METHODS

Univariate and multivariate linear regression analysis were used to assess associations between patients' disposition to conscious control (i.e., Conscious Motor Processing subscale of Movement-Specific Reinvestment Scale; MSRS-CMP) and single-task (Timed-up-and-go test; TuG) and motor dual-task costs (TuG while tone counting; motor DTC%). We determined whether these associations were influenced by patients' walking speed (i.e., 10-m-walk test) and cognitive capacity (i.e., working memory, attention, executive function).

RESULTS

Seventy-eight clinical stroke patients (<6 months post-stroke) participated. Patients' conscious control inclination was not associated with single-task TuG performance. However, patients with a strong inclination for conscious control showed higher motor DTC%. These associations were irrespective of patients' motor and cognitive abilities.

CONCLUSION

Patients' disposition for conscious control was not associated with single task motor performance, but was associated with higher motor dual task costs, regardless of patients' motor or cognitive abilities.

CLINICAL RELEVANCE

Therapists should be aware that patients' conscious control inclination can influence their dual-task performance while moving. Longitudinal studies are required to test whether reducing patients' disposition for conscious control would improve dual-tasking post-stroke.

Relationships between muscle mass, intramuscular adipose and fibrous tissues of the quadriceps, and gait independence in chronic stroke survivors: a cross-sectional study

OBJECTIVE

To examine the relationships between muscle mass, intramuscular adipose and fibrous tissues of the quadriceps, and gait independence in chronic stroke survivors.

DESIGN

Cross-sectional study.

SETTING

Hospital-based research.

PARTICIPANTS

Seventeen chronic stroke survivors who were unable to walk independently (non-independent walker group) and 11 chronic stroke survivors who were able to walk independently (independent walker group) participated in this study. In addition, 25 healthy older adults (healthy group) were enrolled.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The muscle mass and intramuscular adipose and fibrous tissues of the rectus femoris and vastus intermedius were assessed based on muscle thickness and echo intensity of ultrasound images, respectively.

RESULTS

The thicknesses of the rectus femoris and vastus intermedius on the paretic and non-paretic sides in the non-independent walker group were significantly lower than those in the healthy group (mean difference -0.5 to -0.2cm; P<0.001-0.037). The paretic side in the non-independent walker group had significantly higher rectus femoris and vastus intermedius echo intensity compared with the healthy group (mean difference 15.8-17.4; P=0.007-0.025). The thickness of the rectus femoris on the non-paretic side was significantly lower in the independent walker group than in the healthy group (mean difference -0.3cm; P=0.001).

CONCLUSIONS

These results suggest that chronic stroke survivors who are unable to walk independently are likely to experience secondary changes in skeletal muscle on both the paretic and non-paretic sides.

Verbal augmented feedback in the rehabilitation of lower extremity musculoskeletal dysfunctions: a systematic review

Background

Verbal augmented feedback (VAF) is commonly used in physiotherapy rehabilitation of individuals with lower extremity musculoskeletal dysfunction or to induce motor learning for injury prevention. Its effectiveness for acquisition, retention and transfer of learning of new skills in this population is unknown.

Objectives

First, to investigate the effect of VAF for rehabilitation and prevention of lower extremity musculoskeletal dysfunction. Second, to determine its effect on motor learning and the stages of acquisition, retention and transfer in this population.

Design

Systematic review designed in accordance with the Centre for Reviews and Dissemination and reported in line with Preferred Reporting Items for Systematic Review and Meta-analysis.

Method

MEDLINE, Embase, PubMed and five additional databases were searched to identify primary studies with a focus on VAF for prevention and rehabilitation of lower extremity musculoskeletal dysfunction. One reviewer screened the titles and abstracts. Two reviewers retrieved full text articles for final inclusion. The first reviewer extracted data, whereas the second reviewer audited. Two reviewers independently assessed risk of bias and quality of evidence using Cochrane Collaboration’s tool and Grading of Recommendations Assessment, Development and Evaluation, respectively.

Results

Six studies were included, with a total sample of 304 participants. Participants included patients with lateral ankle sprain (n=76), postoperative ACL reconstruction (n=16) and healthy individuals in injury prevention (n=212). All six studies included acquisition, whereas retention was found in five studies. Only one study examined transfer of the achieved motor learning (n=36). VAF was found to be effective for improving lower extremity biomechanics and postural control with moderate evidence from five studies.

Conclusion

VAF should be considered in the rehabilitation of lower extremity musculoskeletal dysfunctions. However, it cannot be unequivocally confirmed that VAF is effective in this population, owing to study heterogeneity and a lack of high-quality evidence. Nevertheless, positive effects on lower extremity biomechanics and postural control have been identified. This suggests that further research into this topic is warranted where an investigation of long-term effects of interventions is required. All stages (acquisition, retention and transfer) should be evaluated.

Randomized Trial on the Effects of Attentional Focus on Motor Training of the Upper Extremity Using Robotics With Individuals After Chronic Stroke

OBJECTIVE

To compare the long-term effects of external focus (EF) and internal focus (IF) of attention after 4 weeks of arm training.

DESIGN

Randomized, repeated-measures, mixed analysis of variance.

SETTING

Outpatient clinic.

PARTICIPANTS

Individuals with stroke and moderate-to-severe arm impairment living in the community (N=33; withdrawals: n=3).

INTERVENTIONS

Four-week arm training protocol on a robotic device (12 sessions).

MAIN OUTCOME MEASURES

Joint independence, Fugl-Meyer Assessment, and Wolf Motor Function Test measured at baseline, discharge, and 4-week follow-up.

RESULTS

There were no between-group effects for attentional focus. Participants in both groups improved significantly on all outcome measures from baseline to discharge and maintained those changes at 4-week follow-up regardless of group assignment (joint independence EF condition: F_1.6,45.4=17.74; P<.0005; partial η²=.39; joint independence IF condition: F_2,56=18.66; P<.0005; partial η²=.40; Fugl-Meyer Assessment: F_2,56=27.83; P<.0005; partial η²=.50; Wolf Motor Function Test: F_2,56=14.05; P<.0005; partial η²=.35).

CONCLUSIONS

There were no differences in retention of motor skills between EF and IF participants 4 weeks after arm training, suggesting that individuals with moderate-to-severe arm impairment may not experience the advantages of an EF found in healthy individuals. Attentional focus is most likely not an active ingredient for retention of trained motor skills for individuals with moderate-to-severe arm impairment, whereas dosage and intensity of practice appear to be pivotal. Future studies should investigate the long-term effects of attentional focus for individuals with mild arm impairment.

Parameters and Measures in Assessment of Motor Learning in Neurorehabilitation; A Systematic Review of the Literature

Upper limb function, essential for daily life, is often impaired in individuals after stroke and cerebral palsy (CP). For an improved upper limb function, learning should occur, and therefore training with motor learning principles is included in many rehabilitation interventions. Despite accurate measurement being an important aspect for examination and optimization of treatment outcomes, there are no standard algorithms for outcome measures selection. Moreover, the ability of the chosen measures to identify learning is not well established. We aimed to review and categorize the parameters and measures utilized for identification of motor learning in stroke and CP populations. PubMed, Pedro, and Web of Science databases were systematically searched between January 2000 and March 2016 for studies assessing a form of motor learning following upper extremity training using motor control measures. Thirty-two studies in persons after stroke and 10 studies in CP of any methodological quality were included. Identified outcome measures were sorted into two categories, “parameters,” defined as identifying a form of learning, and “measures,” as tools measuring the parameter. Review's results were organized as a narrative synthesis focusing on the outcome measures. The included studies were heterogeneous in their study designs, parameters and measures. Parameters included adaptation (n = 6), anticipatory control (n = 2), after-effects (n = 3), de-adaptation (n = 4), performance (n = 24), acquisition (n = 8), retention (n = 8), and transfer (n = 14). Despite motor learning theory's emphasis on long-lasting changes and generalization, the majority of studies did not assess the retention and transfer parameters. Underlying measures included kinematic analyses in terms of speed, geometry or both (n = 39), dynamic metrics, measures of accuracy, consistency, and coordination. There is no exclusivity of measures to a specific parameter. Many factors affect task performance and the ability to measure it—necessitating the use of several metrics to examine different features of movement and learning. Motor learning measures' applicability to clinical setting can benefit from a treatment-focused approach, currently lacking. The complexity of motor learning results in various metrics, utilized to assess its occurrence, making it difficult to synthesize findings across studies. Further research is desirable for development of an outcome measures selection algorithm, while considering the quality of such measurements.

Improved motor performance in patients with acute stroke using the optimal individual attentional strategy

It is believed that motor performance improves when individuals direct attention to movement outcome (external focus, EF) rather than to body movement itself (internal focus, IF). However, our previous study found that an optimal individual attentional strategy depended on motor imagery ability. We explored whether the individual motor imagery ability in stroke patients also affected the optimal attentional strategy for motor control. Individual motor imagery ability was determined as either kinesthetic- or visual-dominant by a questionnaire in 28 patients and 28 healthy-controls. Participants then performed a visuomotor task that required tracing a trajectory under three attentional conditions: no instruction (NI), attention to hand movement (IF), or attention to cursor movement (EF). Movement error in the stroke group strongly depended on individual modality dominance of motor imagery. Patients with kinesthetic dominance showed higher motor accuracy under the IF condition but with concomitantly lower velocity. Alternatively, patients with visual dominance showed improvements in both speed and accuracy under the EF condition. These results suggest that the optimal attentional strategy for improving motor accuracy in stroke rehabilitation differs according to the individual dominance of motor imagery. Our findings may contribute to the development of tailor-made pre-assessment and rehabilitation programs optimized for individual cognitive abilities.

Task-specific reach-to-grasp training after stroke: development and description of a home-based intervention

This series of articles for rehabilitation in practice aims to cover a knowledge element of the rehabilitation medicine curriculum. Nevertheless they are intended to be of interest to a multidisciplinary audience. The competency addressed in this article is to transparently describe the process of developing a complex intervention for people after stroke as part of a feasibility randomised controlled trial.

Objective:

To describe and justify the development of a home-based, task-specific upper limb training intervention to improve reach-to-grasp after stroke and pilot it for feasibility and acceptability prior to a randomized controlled trial.

Intervention description:

The intervention is based on intensive practice of whole reach-to-grasp tasks and part-practice of essential reach-to-grasp components. A ‘pilot’ manual of activities covering the domains of self-care, leisure and productivity was developed for the feasibility study. The intervention comprises 14 hours of therapist-delivered sessions over six weeks, with additional self-practice recommended for 42 hours (i.e. one hour every day). As part of a feasibility randomized controlled trial, 24 people with a wide range of upper limb impairment after stroke experienced the intervention to test adherence and acceptability. The median number of repetitions in one-hour therapist-delivered sessions was 157 (interquartile range IQR 96–211). The amount of self-practice was poorly documented. Where recorded, the median amount of practice was 30 minutes (interquartile range 22–45) per day. Findings demonstrated that the majority of participants found the intensity, content and level of difficulty of the intervention acceptable, and the programme to be beneficial. Comments on the content and presentation of the self-practice material were incorporated in a revised ‘final’ intervention manual.

Discussion:

A comprehensive training intervention to improve reach-to-grasp for people living at home after stroke has been described in accordance with the Template for Intervention Description and Replication (TIDieR) reporting guidelines. The intervention has been piloted, and found to be acceptable and feasible in the home setting.

Trial registration:

ISRCTN56716589

Coaching or gaming? Implications of strategy choice for home based stroke rehabilitation

Background

The enduring aging of the world population and prospective increase of age-related chronic diseases urge the implementation of new models for healthcare delivery. One strategy relies on ICT (Information and Communications Technology) home-based solutions allowing clients to pursue their treatments without institutionalization. Stroke survivors are a particular population that could strongly benefit from such solutions, but is not yet clear what the best approach is for bringing forth an adequate and sustainable usage of home-based rehabilitation systems. Here we explore two possible approaches: coaching and gaming.

Methods

We performed trials with 20 healthy participants and 5 chronic stroke survivors to study and compare execution of an elbow flexion and extension task when performed within a coaching mode that provides encouragement or within a gaming mode. For each mode we analyzed compliance, arm movement kinematics and task scores. In addition, we assessed the usability and acceptance of the proposed modes through a customized self-report questionnaire.

Results

In the healthy participants sample, 13/20 preferred the gaming mode and rated it as being significantly more fun (p < .05), but the feedback delivered by the coaching mode was subjectively perceived as being more useful (p < .01). In addition, the activity level (number of repetitions and total movement of the end effector) was significantly higher (p < .001) during coaching. However, the quality of movements was superior in gaming with a trend towards shorter movement duration (p = .074), significantly shorter travel distance (p < .001), higher movement efficiency (p < .001) and higher performance scores (p < .001). Stroke survivors also showed a trend towards higher activity levels in coaching, but with more movement quality during gaming. Finally, both training modes showed overall high acceptance.

Conclusions

Gaming led to higher enjoyment and increased quality in movement execution in healthy participants. However, we observed that game mechanics strongly determined user behavior and limited activity levels. In contrast, coaching generated higher activity levels. Hence, the purpose of treatment and profile of end-users has to be considered when deciding on the most adequate approach for home based stroke rehabilitation.

Stay Focused! The Effects of Internal and External Focus of Attention on Movement Automaticity in Patients with Stroke

Dual-task performance is often impaired after stroke. This may be resolved by enhancing patients’ automaticity of movement. This study sets out to test the constrained action hypothesis, which holds that automaticity of movement is enhanced by triggering an external focus (on movement effects), rather than an internal focus (on movement execution). Thirty-nine individuals with chronic, unilateral stroke performed a one-leg-stepping task with both legs in single- and dual-task conditions. Attentional focus was manipulated with instructions. Motor performance (movement speed), movement automaticity (fluency of movement), and dual-task performance (dual-task costs) were assessed. The effects of focus on movement speed, single- and dual-task movement fluency, and dual-task costs were analysed with generalized estimating equations. Results showed that, overall, single-task performance was unaffected by focus (p = .341). Regarding movement fluency, no main effects of focus were found in single- or dual-task conditions (p’s ≥ .13). However, focus by leg interactions suggested that an external focus reduced movement fluency of the paretic leg compared to an internal focus (single-task conditions: p = .068; dual-task conditions: p = .084). An external focus also tended to result in inferior dual-task performance (β = -2.38, p = .065). Finally, a near-significant interaction (β = 2.36, p = .055) suggested that dual-task performance was more constrained by patients’ attentional capacity in external focus conditions. We conclude that, compared to an internal focus, an external focus did not result in more automated movements in chronic stroke patients. Contrary to expectations, trends were found for enhanced automaticity with an internal focus. These findings might be due to patients’ strong preference to use an internal focus in daily life. Future work needs to establish the more permanent effects of learning with different attentional foci on re-automating motor control after stroke.