The effect of context on skill acquisition and transfer

Impact of motor task conditions on end-point kinematics and trunk movements during goal-directed arm reach

Task conditions significantly impact human motor control. We investigated how task type, difficulty, and constraints influence the kinematics of goal-directed arm reaching. Non-disabled young adults performed two distinct goal-directed arm reaching tasks: pointing and picking up an object with chopsticks. These tasks were carried out under various conditions, including constrained and unconstrained elbow extension and two different task difficulties. We collected kinematic data using a 3-D motion capture system and analyzed the effects of different task conditions on kinematic variables using linear mixed-effects regression analysis. Our findings revealed statistically significant differences in kinematics between the two tasks. Arm reaching during the picking-up task was slower and exhibited jerkier movements compared to the pointing task. Additionally, when arm reaching was performed with constrained elbow extension, it led to slower and jerkier movements, with an increased involvement of trunk movements compared to the unconstrained condition. These findings show that complex manipulative motor tasks requiring higher hand dexterity necessitate feedback-based control of arm reaching, but simple pointing tasks requiring less hand dexterity do not. In conclusion, our study sheds light on the influence of task conditions on goal-directed arm reaching kinematics and provides valuable insights into the motor control strategies involved in different tasks.

Usability and performance validation of an ultra-lightweight and versatile untethered robotic ankle exoskeleton

BACKGROUND

Ankle exoskeletons can improve walking mechanics and energetics, but few untethered devices have demonstrated improved performance and usability across a wide range of users and terrains. Our goal was to design and validate a lightweight untethered ankle exoskeleton that was effective across moderate-to-high intensity ambulation in children through adults with and without walking impairment.

METHODS

Following benchtop validation of custom hardware, we assessed the group-level improvements in walking economy while wearing the device in a diverse unimpaired cohort (n = 6, body mass = 42-92 kg). We also conducted a maximal exertion experiment on a stair stepping machine in a small cohort of individuals with cerebral palsy (CP, n = 5, age = 11-33 years, GMFCS I-III, body mass = 40-71 kg). Device usability metrics (device don and setup times and System Usability Score) were assessed in both cohorts.

RESULTS

There was a 9.9 ± 2.6% (p = 0.012, range = 0-18%) reduction in metabolic power during exoskeleton-assisted inclined walking compared to no device in the unimpaired cohort. The cohort with CP was able to ascend 38.4 ± 23.6% (p = 0.013, range = 3-132%) more floors compared to no device without increasing metabolic power (p = 0.49) or perceived exertion (p = 0.50). Users with CP had mean device don and setup times of 3.5 ± 0.7 min and 28 ± 6 s, respectively. Unimpaired users had a mean don time of 1.5 ± 0.2 min and setup time of 14 ± 1 s. The average exoskeleton score on the System Usability Scale was 81.8 ± 8.4 ("excellent").

CONCLUSIONS

Our battery-powered ankle exoskeleton was easy to use for our participants, with initial evidence supporting effectiveness across different terrains for unimpaired adults, and children and adults with CP. Trial registration Prospectively registered at ClinicalTrials.gov (NCT04119063) on October 8, 2019.

The effect of time spent in rehabilitation on activity limitation and impairment after stroke

BACKGROUND

Stroke affects millions of people every year and is a leading cause of disability, resulting in significant financial cost and reduction in quality of life. Rehabilitation after stroke aims to reduce disability by facilitating recovery of impairment, activity, or participation. One aspect of stroke rehabilitation that may affect outcomes is the amount of time spent in rehabilitation, including minutes provided, frequency (i.e. days per week of rehabilitation), and duration (i.e. time period over which rehabilitation is provided). Effect of time spent in rehabilitation after stroke has been explored extensively in the literature, but findings are inconsistent. Previous systematic reviews with meta-analyses have included studies that differ not only in the amount provided, but also type of rehabilitation.

OBJECTIVES

To assess the effect of 1. more time spent in the same type of rehabilitation on activity measures in people with stroke; 2. difference in total rehabilitation time (in minutes) on recovery of activity in people with stroke; and 3. rehabilitation schedule on activity in terms of: a. average time (minutes) per week undergoing rehabilitation, b. frequency (number of sessions per week) of rehabilitation, and c. total duration of rehabilitation.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register, CENTRAL, MEDLINE, Embase, eight other databases, and five trials registers to June 2021. We searched reference lists of identified studies, contacted key authors, and undertook reference searching using Web of Science Cited Reference Search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adults with stroke that compared different amounts of time spent, greater than zero, in rehabilitation (any non-pharmacological, non-surgical intervention aimed to improve activity after stroke). Studies varied only in the amount of time in rehabilitation between experimental and control conditions. Primary outcome was activities of daily living (ADLs); secondary outcomes were activity measures of upper and lower limbs, motor impairment measures of upper and lower limbs, and serious adverse events (SAE)/death.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened studies, extracted data, assessed methodological quality using the Cochrane RoB 2 tool, and assessed certainty of the evidence using GRADE. For continuous outcomes using different scales, we calculated pooled standardised mean difference (SMDs) and 95% confidence intervals (CIs). We expressed dichotomous outcomes as risk ratios (RR) with 95% CIs.

MAIN RESULTS

The quantitative synthesis of this review comprised 21 parallel RCTs, involving analysed data from 1412 participants.  Time in rehabilitation varied between studies. Minutes provided per week were 90 to 1288. Days per week of rehabilitation were three to seven. Duration of rehabilitation was two weeks to six months. Thirteen studies provided upper limb rehabilitation, five general rehabilitation, two mobilisation training, and one lower limb training. Sixteen studies examined participants in the first six months following stroke; the remaining five included participants more than six months poststroke. Comparison of stroke severity or level of impairment was limited due to variations in measurement. The risk of bias assessment suggests there were issues with the methodological quality of the included studies. There were 76 outcome-level risk of bias assessments: 15 low risk, 37 some concerns, and 24 high risk. When comparing groups that spent more time versus less time in rehabilitation immediately after intervention, we found no difference in rehabilitation for ADL outcomes (SMD 0.13, 95% CI -0.02 to 0.28; P = 0.09; I2 = 7%; 14 studies, 864 participants; very low-certainty evidence), activity measures of the upper limb (SMD 0.09, 95% CI -0.11 to 0.29; P = 0.36; I2 = 0%; 12 studies, 426 participants; very low-certainty evidence), and activity measures of the lower limb (SMD 0.25, 95% CI -0.03 to 0.53; P = 0.08; I2 = 48%; 5 studies, 425 participants; very low-certainty evidence). We found an effect in favour of more time in rehabilitation for motor impairment measures of the upper limb (SMD 0.32, 95% CI 0.06 to 0.58; P = 0.01; I2 = 10%; 9 studies, 287 participants; low-certainty evidence) and of the lower limb (SMD 0.71, 95% CI 0.15 to 1.28; P = 0.01; 1 study, 51 participants; very low-certainty evidence). There were no intervention-related SAEs. More time in rehabilitation did not affect the risk of SAEs/death (RR 1.20, 95% CI 0.51 to 2.85; P = 0.68; I2 = 0%; 2 studies, 379 participants; low-certainty evidence), but few studies measured these outcomes. Predefined subgroup analyses comparing studies with a larger difference of total time spent in rehabilitation between intervention groups to studies with a smaller difference found greater improvements for studies with a larger difference. This was statistically significant for ADL outcomes (P = 0.02) and activity measures of the upper limb (P = 0.04), but not for activity measures of the lower limb (P = 0.41) or motor impairment measures of the upper limb (P = 0.06).

AUTHORS' CONCLUSIONS

An increase in time spent in the same type of rehabilitation after stroke results in little to no difference in meaningful activities such as activities of daily living and activities of the upper and lower limb but a small benefit in measures of motor impairment (low- to very low-certainty evidence for all findings). If the increase in time spent in rehabilitation exceeds a threshold, this may lead to improved outcomes. There is currently insufficient evidence to recommend a minimum beneficial daily amount in clinical practice. The findings of this study are limited by a lack of studies with a significant contrast in amount of additional rehabilitation provided between control and intervention groups. Large, well-designed, high-quality RCTs that measure time spent in all rehabilitation activities (not just interventional) and provide a large contrast (minimum of 1000 minutes) in amount of rehabilitation between groups would provide further evidence for effect of time spent in rehabilitation.

Ankle Exoskeleton Assistance Can Improve Over-Ground Walking Economy in Individuals With Cerebral Palsy

Individuals with neuromuscular impairment from conditions like cerebral palsy face reduced quality of life due to diminishing mobility and independence. Lower-limb exoskeletons have potential to aid mobility, yet few studies have investigated their use during over-ground walking - an exercise that may contribute to our understanding of potential benefit in free-living settings. The goal of this study was to determine the potential for adaptive plantar-flexor assistance from an untethered ankle exoskeleton to improve over-ground walking economy and speed. Six individuals with cerebral palsy completed three consecutive daily over-ground training sessions to acclimate to, and tune, assistance. During a final assessment visit, metabolic cost, walking speed, and soleus electromyography were collected for baseline, unpowered, low, training-tuned, and high assistance conditions. Compared to each participant's baseline condition, we observed a 3.9 ± 1.9% (p = 0.050) increase in walking speed and a 22.0 ± 4.5% (p = 0.002) reduction in soleus activity with training-tuned assistance; metabolic cost of transport was unchanged (p = 0.130). High assistance resulted in an 8.5 ± 4.0% (p = 0.042) reduction in metabolic cost of transport, a 6.3 ± 2.6% (p = 0.029) increase in walking speed, and a 25.0 ± 4.0% (p < 0.001) reduction in soleus activity. Improvement in exoskeleton-assisted walking economy was related to pre-training baseline walking speed ( [Formula: see text], p = 0.001); the slower and more impaired participants improved the most. Energy cost and preferred walking speed remained generally unchanged for the faster and less impaired participants. These findings demonstrate that powered ankle exoskeletons have the potential to improve mobility-related outcomes for some people with cerebral palsy.

Evidence-based position paper on Physical and Rehabilitation Medicine professional practice for Adults with Acquired Brain Injury. The European PRM position (UEMS PRM Section)

BACKGROUND

Acquired brain injury (ABI) is damage to the brain that occurs after birth caused either by a traumatic or by a nontraumatic injury. The rehabilitation process following ABI should be performed by a multi-professional team, working in an interdisciplinary way, with the aim of organizing a comprehensive and holistic approach to persons with every severity of ABI. This Evidence Based Position Paper represents the official position of the European Union through the UEMS Physical and Rehabilitation Medicine (PRM) Section and designates the professional role of PRM physicians for people with ABI. The aim was to formulate recommendations on the PRM physician's professional practice for persons with ABI in order to promote their functioning and enhance quality of life.

METHODS

This paper has been developed according to the methodology defined by the Professional Practice Committee of the UEMS-PRM Section: a systematic literature search has been performed in PubMed and Core Clinical Journals. On the basis of the selected papers, recommendations have been made as a result of five Delphi rounds.

RESULTS

The literature review as well as thirty-one recommendations are presented.

CONCLUSIONS

The expert consensus is that structured, comprehensive and holistic rehabilitation program delivered by the multi-professional team, working in an interdisciplinary way, with the leadership and coordination of the PRM physician, is likely to be effective, especially for those with severe disability after brain injury.

Effects of phase proprioceptive training on balance in patients with chronic stroke

[Purpose] This study aimed to investigate the effect of phase proprioceptive training on balance in patients with chronic stroke. [Subjects and Methods] Participants included 30 patients with stroke who were randomly assigned to the proprioceptive training group (n=15) or control group (n=15). Participants in the proprioceptive training group underwent proprioceptive training and received general physical therapy each for a total of 20 thirty-minute sessions, five times per week, during a period of four weeks; the control group received general physical therapy for a total of 20 sixty-minute sessions, five times per week, during a period of four weeks. [Results] All participants were evaluated with the Berg Balance Scale, Timed Up and Go (TUG) test, and Activities-specific Balance Confidence (ABC) Scale instrument before and after intervention. After training, the differences in BBS, TUG, and ABC scores in the proprioceptive group were significantly greater than those in the control group. [Conclusion] In conclusion, proprioceptive training was effective on balance ability. Therefore, proprioceptive training may be efficient when combining general physical therapy with phase proprioceptive training for patients with impairments of balance. Further research is needed to investigate proprioceptive training methods.

Does a short period of rehabilitation in the home setting facilitate functioning after stroke? A randomized controlled trial

Objective: To assess the effect of three weeks of rehabilitation in the home setting for younger patients with stroke with the aim of improving activity level.

Design: A randomized controlled study with blinded evaluations at discharge, three weeks, three months and one year after discharge.

Setting: Home of the patient or the ordinary day rehabilitation clinic at the university hospital.

Subjects: Fifty-eight patients (median age 53 years) consecutively discharged from inpatient rehabilitation with a first occurrence of stroke participated in training directly after discharge.

Intervention: Rehabilitation was given for 9 hours/week over three weeks. The home group received individually tailored training, based on the patient's needs and desires, with a focus on activities in their natural context. Support and information were also given. The intervention in the day clinic group was aimed mainly at improved functions.

Main measures: The main outcome was activity, assessed with the Assessment of Motor and Process Skill (AMPS). The impairment level was also evaluated. Costs were estimated.

Result: There were no significant differences between the groups on any of the four assessments. However, there seemed to be an earlier improvement on some measures (including AMPS) for the home group. For both groups there was a greater improvement on the activity level than on the impairment level. The costs of the home group were less than half of the costs of the day clinic group.

Conclusion: With the present results, both rehabilitation programmes could be recommended, however, further studies are needed to define patients who may specifically benefit from the home rehabilitation programme. Costs should be taken into consideration.

Is the repetitive training of complex hand and arm movements benefi cial for motor recovery in stroke patients?

Objective: To determine whether a repetitive training of complex movements of arm and hand contributes to functional recovery in stroke patients.

Design: Prospective, longitudinal, multiple baseline design across individuals. Setting: Neurological rehabilitation centre.

Subjects: Twenty-one patients with stroke in the middle cerebral artery territory.

Interventions: Baseline phase: ‘house-typical’ occupational and physiotherapy; training phase: ‘house-typical’ therapy supplemented by repetitive training of (1) grasping and transport movements and (2) sawing movements of the affected arm over 10 minutes each, twice daily, five days per week.

Main outcome measures: Rivermead Motor Assessment (RMA, arm section), grip strength, rapid isotonic hand extension, three-dimensional motion analysis.

Results: Patients experienced a continuous functional improvement of the affected arm (RMA score from initial 4.9 ± 2.1 to 8.0 ± 4.6, p < 0.001) and an increase of grip strength during the baseline and the training phase (from initial 102.4 ± 43.3 N to 150.6 ± 118.9 N, p < 0.05). Movement analysis revealed a trend to a more precise movement execution. The repetitive training of complex movements did not result in an additional benefit.

Conclusion: The repetitive training of complex movements does not further enhance the functional recovery of the affected arm and hand in stroke patients compared with functionally based occupational and physiotherapy.

Perceived Risk and its Effects on Quality of Movement in Occupational Performance of Well-Elderly Individuals

The purpose of this study was to determine whether elderly individuals would demonstrate differences in quality of movement when completing a water-pouring task under different levels of perceived risk (i.e., pouring hot water vs. pouring cold water during beverage preparation). Fifty individuals over the age of 65 (M=72.1 years, SD=6.3) participated in the repeated measures, counterbalanced design. Results indicated that participants used less efficient movement dynamics when pouring hot water (higher risk) than when pouring cold water (lower risk). Elders tended to take longer and make more adjustments when pouring hot water than when pouring cold water. Occupational therapists can use this information to better understand the movement dynamics needed during everyday occupations and design therapeutic interventions that appropriately challenge clients.

Effect of robotic-assisted three-dimensional repetitive motion to improve hand motor function and control in children with handwriting deficits: a nonrandomized phase 2 device trial

OBJECTIVE

We explored the efficacy of robotic technology in improving handwriting in children with impaired motor skills.

METHOD

Eighteen participants had impairments arising from cerebral palsy (CP), autism spectrum disorder (ASD), attention deficit disorder (ADD), attention deficit hyperactivity disorder (ADHD), or other disorders. The intervention was robotic-guided three-dimensional repetitive motion in 15-20 daily sessions of 25-30 min each over 4-8 wk.

RESULTS

Fine motor control improved for the children with learning disabilities and those ages 9 or older but not for those with CP or under age 9. All children with ASD or ADHD referred for slow writing speed were able to increase speed while maintaining legibility.

CONCLUSION

Three-dimensional, robot-assisted, repetitive motion training improved handwriting fluidity in children with mild to moderate fine motor deficits associated with ASD or ADHD within 10 hr of training. This dosage may not be sufficient for children with CP.

Using Purposeful Tasks to Improve Motor Performance: Does Object Affordance Matter?

Introduction:

Purposeful activity is believed to yield better results than meaningless exercises during motor rehabilitation. The objective of this paper is to provide a narrative review of the literature regarding the influence of object affordance on motor performance, a factor that contributes to the purposefulness of a task.

Method:

Thirty-five reviewed articles were selected following an online search on PubMed, Cinahl and Google Scholar and an inspection of their references. Results of reviewed studies are discussed in relation to (1) the different approaches used to increase object affordance; (2) the influence of clinical conditions on the relationship between object affordance and motor performance; and (3) the influence of object affordance on immediate motor performance vs motor learning.

Findings:

The three main approaches used to increase object affordance relate to (a) the number of objects used during the task; (b) the functional information that these objects convey; and (c) the functional goals of the task. Reviewed results suggest that increasing object affordance can produce beneficial effects on immediate motor performance and motor learning, and especially support the effect of varying the number of objects. However, most evidence on object affordance has not come from high quality research.

Conclusion:

Clinicians should favour the use of tasks with high object affordance during both clinical assessment and therapy in order to promote optimal motor performance. More high quality research is needed to assess the influence of object affordance during therapy and on long-term motor learning and clinical outcomes.

Aquatic therapy for a child with type III spinal muscular atrophy: a case report

Spinal muscular atrophy (SMA) is a neuromuscular disorder characterized by degeneration of alpha motor neurons. This case report describes an aquatic therapy program and the outcomes for a 3-year-old girl with type III SMA. Motor skills were examined using the 88-item Gross Motor Function Measure (GMFM), the Peabody Developmental Motor Scales (PDMS-2), and the GAITRite system. The child received aquatic therapy twice per week for 45-min sessions, for 14 weeks. The intervention included aquatic activities designed to improve gross motor skills and age-appropriate functional mobility. The GMFM total score improved by 11% following the intervention. The Standing Dimension score improved by 28% and the Walking, Running, and Jumping Dimension score improved by 18%. The gross motor quotient for the PDMS-2 improved from 66 to 74. The child's gait showed improvement in walking velocity, stride length, and single-limb support time as a percentage of the gait cycle. The outcomes of this case report demonstrate the successful improvement of gross motor function and gait in a 3-year-old child with SMA. This study provides clinical information for therapists utilizing aquatic therapy as a modality for children with neuromuscular disorders.

A reflection on motor learning theory in pediatric occupational therapy practice

BACKGROUND

Theory provides a guide to clinical practice. To date, the most prevalent theories in pediatric occupational therapy practice are sensory integration and neurodevelopmental treatment.

PURPOSE

The purpose of this paper is to present a brief overview and reflection on motor learning theories as well as a summary of motor learning principles that can be used in pediatric practice.

KEY ISSUES

Over the past two decades, motor learning theory has been applied in adult occupational therapy practice, but it has been slow to gain popularity in pediatrics.

IMPLICATIONS

Although therapists may be tacitly applying motor learning principles in practice, conscious and deliberate application of these principles to a variety of pediatric populations is required to determine if motor learning theory provides a viable and effective contribution to evidence-based, occupational therapy pediatric practice. Further research comparing motor learning interventions to other dominant interventions in pediatric occupational therapy is warranted.

Technology-assisted training of arm-hand skills in stroke: concepts on reacquisition of motor control and therapist guidelines for rehabilitation technology design

Background

It is the purpose of this article to identify and review criteria that rehabilitation technology should meet in order to offer arm-hand training to stroke patients, based on recent principles of motor learning.

Methods

A literature search was conducted in PubMed, MEDLINE, CINAHL, and EMBASE (1997–2007).

Results

One hundred and eighty seven scientific papers/book references were identified as being relevant. Rehabilitation approaches for upper limb training after stroke show to have shifted in the last decade from being analytical towards being focussed on environmentally contextual skill training (task-oriented training). Training programmes for enhancing motor skills use patient and goal-tailored exercise schedules and individual feedback on exercise performance. Therapist criteria for upper limb rehabilitation technology are suggested which are used to evaluate the strengths and weaknesses of a number of current technological systems.

Conclusion

This review shows that technology for supporting upper limb training after stroke needs to align with the evolution in rehabilitation training approaches of the last decade. A major challenge for related technological developments is to provide engaging patient-tailored task oriented arm-hand training in natural environments with patient-tailored feedback to support (re) learning of motor skills.

Development and Testing of Interventions in Occupational Therapy: Toward a New Generation of Research in Occupational Therapy

Development, refinement, and testing of occupational therapy interventions require a systematic approach. The authors explain the four phases for clinical trials used in pharmaceutical research and apply them to the development and testing of occupational therapy interventions. The challenges faced by occupational therapy researchers in designing clinical trials include difficulties in specifying the intervention, blinding subjects, therapists, and evaluators, and identifying objective but client-centered measures of primary outcomes. Examples are provided of researchers who have developed and tested occupational therapy interventions in phases.

Reach adaptation: what determines whether we learn an internal model of the tool or adapt the model of our arm?

We make errors when learning to use a new tool. However, the cause of error may be ambiguous: is it because we misestimated properties of the tool or of our own arm? We considered a well-studied adaptation task in which people made goal-directed reaching movements while holding the handle of a robotic arm. The robot produced viscous forces that perturbed reach trajectories. As reaching improved with practice, did people recalibrate an internal model of their arm, or did they build an internal model of the novel tool (robot), or both? What factors influenced how the brain solved this credit assignment problem? To investigate these questions, we compared transfer of adaptation between three conditions: catch trials in which robot forces were turned off unannounced, robot-null trials in which subjects were told that forces were turned off, and free-space trials in which subjects still held the handle but watched as it was detached from the robot. Transfer to free space was 40% of that observed in unannounced catch trials. We next hypothesized that transfer to free space might increase if the training field changed gradually, rather than abruptly. Indeed, this method increased transfer to free space from 40 to 60%. Therefore although practice with a novel tool resulted in formation of an internal model of the tool, it also appeared to produce a transient change in the internal model of the subject's arm. Gradual changes in the tool's dynamics increased the extent to which the nervous system recalibrated the model of the subject's own arm.

Self-generation to improve learning and memory of functional activities in persons with multiple sclerosis: meal preparation and managing finances

OBJECTIVE

To examine the utility of using a self-generation strategy to improve learning and performance of everyday functional tasks in persons with multiple sclerosis (MS).

DESIGN

Mixed-design with both a within- and between-subject factor.

SETTING

Nonprofit rehabilitation research institution.

PARTICIPANTS

Participants (n=20) with MS and healthy controls (n=18).

INTERVENTIONS

Participants completed 2 meal preparation and 2 financial management tasks. One task in each area was presented in the provided condition, in which all instructions were provided to and read by the participants, and the other task was presented in the generated condition, in which participants were asked to generate (fill in the blank) the necessary items needed to perform each step of the task.

MAIN OUTCOME MEASURES

Correct recall of task items and step sequence immediately and 1 week after initial learning and correct performance of task items and step sequence 30 minutes after initial learning. The maximum possible score in each of the recall tests was 24.

RESULTS

Although the MS and healthy groups did not differ in overall items recalled, in both groups tasks learned in the generated condition enhanced memory performance significantly for the tasks used when compared with similar tasks learned in the provided condition.

CONCLUSIONS

Self-generation during learning can significantly improve subsequent recall of information and performance of activities of daily living for persons with MS. Implications of these findings for cognitive rehabilitation in MS are discussed.

Effects of object use on reaching and postural balance: a comparison of patients with unilateral stroke and healthy controls

OBJECTIVE

To evaluate whether the functional use of certain task objects while standing influences reaching performance and postural balance in persons with left or right cerebral vascular accidents, and also in healthy individuals.

DESIGN

Thirty-five stroke patients (20 patients with left and 15 patients with right cerebral vascular accidents) and 31 healthy controls (15 using the left and 16 the right arm) performed two experimental reaching tasks (task object present vs. absent) using the less affected arm while standing. For the object-present task, subjects held a glass and moved it forward as far as possible. For the object-absent task, subjects simply reached forward as far as possible. We measured reaching performance using kinematic analysis and assessed postural control using derivatives of the center of pressure, including forward displacement, mediolateral shift, and average velocity.

RESULTS

Object presence did not significantly improve overall reaching performance in any group. However, for patients with left cerebral vascular accidents and controls (using either the left or the right arm), there were significant effects of object presence on the average velocity of the center of pressure. For patients with right cerebral vascular accidents, there were significant effects of task object on the forward distance and average velocity of the center of pressure.

CONCLUSIONS

The positive findings regarding center-of-pressure derivatives suggest that a functional use of objects during a standing reaching task can decrease postural sway, as represented by the average velocity of the center of pressure, in individuals with and without stroke. Patients with right cerebral vascular accidents may benefit considerably more from functional object use during a standing reaching task, apparently because such tasks can facilitate greater forward displacement of the center of pressure.

Stroke recovery and its imaging

Functional imaging of stroke recovery is a unique source of information that might be useful in the development of restorative treatments. Several features of brain function change spontaneously after stroke. Current studies define many of the most common events. Key challenges for the future are to develop standardized approaches to help address certain questions, determine the psychometric qualities of these measures, and define the clinical usefulness of these methods.

Effects of visual feedback rhythmic weight-shift training on hemiplegic stroke patients

OBJECTIVE

To assess the balance function of hemiplegic stroke patients and to investigate whether visual feedback rhythmic weight-shift training following acute stroke can decrease falls among patients with hemiplegic stroke.

DESIGN

A prospective study, using a Balance Master.

SETTING

Hospital-based rehabilitation units.

SUBJECTS

Fifty-two hemiplegic stroke patients (28 in the training group and 24 in the control group).

INTERVENTIONS

Conventional stroke rehabilitation programme plus visual feedback rhythmic weight-shift training. Training effect was evaluated by assessing the static and dynamic balance performance as well as comparing the occurrence of falls in the training and control groups at six-month follow-up.

MAIN MEASURES

Occurrence of falls; static balance in different sensory conditions; and dynamic balance performance, including on-axis velocity and directional control during rhythmic weight-shift.

RESULTS

Significant improvement in dynamic balance performance was found in hemiplegic patients in the training group. The improvement was sustained for six months. With regarding to static balance function, no significant improvement was found. At six-month follow-up, 5 of 28 patients (17.8%) in the training group had fallen, compared with 10 of 24 patients (41.7%) in the control group. The occurrence of falls decreased, although not statistically significantly (p=0.059).

CONCLUSIONS

Visual feedback rhythmic weight-shift training may improve dynamic balance function for hemiplegic stroke patients. The effects of training may be sustained for six months. The occurrence of falls decreased in the training group, but not statistically significantly.

Base of support feedback in gait rehabilitation

The purpose of this study was to investigate the effect of feedback information about base of support in gait rehabilitation. Sixteen individuals with hemiparesis resulting in narrow base of support, were randomly placed into two equal groups, experimental and control. The experimental group was provided with a portable device that provided extrinsic auditory feedback information about base of support incorporated in the functional context of conventional gait therapy, whereas the control group received a conventional gait therapy only. Changes in step width with treatment were assessed with step print technique. The experimental group of subjects improved their step width with treatment from 0.09 +/- 0.003 m to 0.16 +/- 0.006 m while individuals assigned to the control group showed smaller improvement from 0.099 +/- 0.004 m to 0.13 +/- 0.003 m. While both groups demonstrated statistically significant improvement (p < 0.05), the level of recovery of step width seen in the experimental group was greater.

A randomized controlled comparison of upper-extremity rehabilitation strategies in acute stroke: a pilot study of immediate and long-term outcomes

OBJECTIVE

To evaluate the immediate and long-term effects of 2 upper-extremity rehabilitation approaches for stroke compared with standard care in participants stratified by stroke severity.

DESIGN

Nonblinded, randomized controlled trial (baseline, postintervention, 9mo) design.

SETTING

Inpatient rehabilitation hospital and outpatient clinic.

PARTICIPANTS

Sixty-four patients with recent stroke admitted for inpatient rehabilitation were randomized within severity strata (Orpington Prognostic Scale) into 1 of 3 intervention groups. Forty-four patients completed the 9-month follow-up.

INTERVENTIONS

Standard care (SC), functional task practice (FT), and strength training (ST). The FT and ST groups received 20 additional hours of upper-extremity therapy beyond standard care distributed over a 4- to 6-week period.

MAIN OUTCOME MEASURES

Performance measures of impairment (Fugl-Meyer Assessment), strength (isometric torque), and function (Functional Test of the Hemiparetic Upper Extremity [FTHUE]).

RESULTS

Compared with SC participants, those in the FT and ST groups had significantly greater increases in Fugl-Meyer motor scores (P=.04) and isometric torque (P=.02) posttreatment. Treatment benefit was primarily in the less severe participants, where improvement in FT and ST group Fugl-Meyer motor scores more than doubled that of the SC group. Similar results were found for the FTHEU and isometric torque. During the long term, at 9 months, the less severe FT group continued to make gains in isometric muscle torque, significantly exceeding those of the ST group (P<.05).

CONCLUSIONS

Task specificity and stroke severity are important factors for rehabilitation of arm use in acute stroke. Twenty hours of upper extremity-specific therapy over 4 to 6 weeks significantly affected functional outcomes. The immediate benefits of a functional task approach were similar to those of a resistance-strength approach, however, the former was more beneficial in the long-term.

Bilateral facilitation of motor control in chronic hemiplegia

The present study addressed the efficacy of concurrently moving both arms, with and without a load added to the uninvolved arm, in facilitating the quality of movement of the involved side in individuals with moderate, chronic hemiplegia. Six hemiplegic cerebrovascular accident (CVA) subjects with left-hemisphere lesions participated in the study. The four males and two females ranged from 46 to 77 years of age and 30-96 months post-CVA. All subjects scored at least 70% on the Fugl-Meyer test of motor function. The task was to perform discrete unilateral and bilateral elbow extensions in the horizontal plane. The movements were 45 degrees in amplitude and were to terminate in a 10 degrees target zone that was indicated by an illustration of a coffee mug. The instructions were to move toward the mug as smoothly as possible in a movement time (MT) determined to be 20% longer than their minimal MT for that distance. The primary dependent variable was the percentage of continuous vs. discontinuous trajectories observed in each condition, based on whether or not a transient hesitation or reversal was observed. Phase of peak velocity was also quantified as a general indication of the symmetry of the velocity profile. Three of the six subjects exhibited a greater percentage of continuous movements of the involved arm in the nonloaded bilateral condition than the unimanual condition. Five subjects benefited when the uninvolved arm was inertially loaded in the bilateral condition when compared with unimanual performance. Only the oldest subject failed to exhibit facilitation. Peak velocity phase tended to normalize toward symmetry in the bilateral conditions. These findings are consistent with prior evidence that the control of the involved arm improves during bimanual performance for some hemiplegic subjects. It further suggests loading the uninvolved arm may benefit some subjects with respect to unimanual performance, with age perhaps playing a role in determining efficacy.

Effects of cognitive processes and task complexity on acquisition, retention, and transfer of motor skills

This experiment was designed to investigate the effect of cognitive problem-solving operations (termed contextual interference) and complexity of tasks on the acquisition retention and transfer of motor skills. Ninety-six children, ages 7.5-9.5 practiced the task of throwing beanbags under either low contextual interference (blocked practice), high contextual interference (random practice) or medium contextual interference (combined practice). Half of the participants acquired a complex task and the other half a simple task. All participants performed 30 acquisition trials, 9 retention trials and 4 transfer trials. Results indicated that participants who practiced in the blocked practice group did not differ in their performance whether they acquired complex or simple tasks. On the other hand, participants from the random and combined practice groups who acquired simple tasks performed better than those who acquired complex tasks. These findings support the hypothesis that there is a limit to the interference during practice that will benefit retention and transfer, thus creating the contextual interference effect. It seems that the complex-task condition combined with random or combined practice schedule increased the difficulty of acquisition, possibly impeding the cognitive processing during acquisition, thus impairing the learning process.

Effects of Cognitive Processes and Task Complexity on Acquisition, Retention, and Transfer of Motor Skills

This experiment was designed to investigate the effect of cognitive problem-solving operations (termed contextual interference) and complexity of tasks on the acquisition retention and transfer of motor skills. Ninety-six children, ages 7.5-9.5 practised the task of throwing beanbags under either low contextual interference (blocked practice), high contextual interference (random practice) or medium contextual interference (combined practice). Half of the participants acquired a complex task and the other half a simple task. All participants performed 30 acquisition trials, 9 retention trials and 4 transfer trials. Results indicated that participants who practised in the blocked practice group did not differ in their performance whether they acquired complex or simple tasks. On the other hand, participants from the random and combined practice groups who acquired simple tasks performed better than those who acquired complex tasks. These findings support the hypothesis that there is a limit to the interference during practice that will benefit retention and transfer, thus creating the contextual interference effect. It seems that the complex-task condition combined with random or combined practice schedule increased the difficulty of acquisition, possibly impeding the cognitive processing during acquisition, thus impairing the learning process.

Use of Visual Feedback in Retraining Balance Following Acute Stroke

Background and Purpose. Visual feedback related to weight distribution and center-of-pressure positioning has been shown to be effective in increasing stance symmetry following stroke, although it is not clear whether functional balance ability also improves. This study compared the relative effectiveness of visual feedback training of center-of-gravity (CoG) positioning with conventional physical therapy following acute stroke. Subjects. Forty-six people who had strokes within 80 days before the study, resulting in unilateral hemiparesis, and who were in need of balance retraining participated. Methods and Materials. Initially, subjects were randomly assigned to visual feedback or conventional physical therapy groups for balance retraining until 16 subjects per group were recruited. The next 14 subjects were assigned to a control group. All subjects received physical therapy and occupational therapy (regular therapy) 2 hours a day, and subjects in the 2 experimental groups received additional balance training 30 minutes a day until discharge. The visual feedback group received information about their CoG position as they shifted their weight during various activities. The conventional therapy group received verbal and tactile cues to encourage symmetrical stance and weight shifting. Static (postural sway) and activity-based measures of balance (Berg Balance Scale, gait speed, and the Timed “Up & Go” Test) were contrasted across the 3 groups at baseline, at discharge, and at 1 month following discharge using an analysis of variance for repeated measures. Results. All groups demonstrated marked improvement over time for all measures of balance ability, with the greatest improvements occurring in the period from baseline to discharge. No between-group differences were detected in any of the outcome measures. Conclusion and Discussion. Visual feedback or conventional balance training in addition to regular therapy affords no added benefit when offered in the early stages of rehabilitation following stroke.

Rationales for improving motor function

New findings in basic neuroscience, and the growing knowledge regarding neuroplasticity and motor learning have exerted influence and have provided stimuli for motor rehabilitation research. Repeated motor practice has been identified as crucial for motor recovery. Further novel and scientifically based therapeutic approaches have been developed: constraint-induced movement therapy, electromyogram-initiated neuromuscular stimulation, motor imagery and music therapy are all discussed in the present review.