Bimanual Skills Research Articles

Changes in the bimanual skills of children with Unilateral Cerebral Palsy following blocks of Bobath therapy

Changes in the bimanual skills of children with Unilateral Cerebral Palsy following blocks of Bobath therapy

Neuropsychological Impairment in School-Aged Children Born to Mothers With Gestational Diabetes

The aim of this study was to determine whether school-aged children born to mothers with gestational diabetes show delays in their neuropsychological development. Several key neuropsychological characteristics of 32 children aged 7 to 9 years born to mothers with gestational diabetes were examined by comparing their performance on cognitive tasks to that of 28 children aged 8 to 10 years whose mothers had glucose levels within normal limits during pregnancy. The gestational diabetes group showed low performance on graphic, spatial, and bimanual skills and a higher presence of soft neurologic signs. Lower scores for general intellectual level and the working memory index were also evident. Our results suggest that gestational diabetes is associated with mild cognitive impairment.

Corticopontocerebellar Connectivity Disruption in Congenital Hemiplegia

Background. Crossed cerebellar diaschisis is the disruption of functional connectivity between cerebrum and cerebellum after hemispheric unilateral brain lesions. In adults and to a lesser extent in children, crossed cerebellar diaschisis has been largely investigated by functional connectivity and demonstrated to influence paretic hand function. Objective. We aim to demonstrate a disruption in structural corticopontocerebellar (CPC) connectivity in children with congenital brain lesions and examine its correlation with paretic hand motor function. Methods. Thirty-six children (Manual Ability Classification System: I, n = 21; II, n = 15) with unilateral brain lesions and 18 controls were analyzed in a case-control study, and diffusion magnetic resonance imaging data were acquired at 3T. High angular resolution diffusion imaging probabilistic tractography was employed for the region of interest–based reconstruction of CPC tracts. To identify statistical differences in structural cerebrocerebellar connectivity between case and control groups, an asymmetry index based on the number of streamlines of CPC tracts was used. In the case group, the correlation between asymmetry index and hand function measures was also determined. Results. Projections through the middle cerebellar peduncle to the contralateral cerebral cortex showed greater asymmetry in children with congenital unilateral brain lesion compared to controls (P = .03), thus indicating a disruption of structural cerebrocerebellar connectivity. The degree of asymmetry index showed a correlation (P < .03; r = −0.31) with impaired hand abilities in bimanual tasks. Conclusions. Disruption of structural cerebrocerebellar connectivity is present in patients with congenital unilateral brain injury and might be related to impaired hand function in bimanual skills, with potential implication in tailoring early intervention strategies.

Learning to tie well with others: bimanual versus intermanual performance of a highly practised skill

Studies indicate that novices are faster in manual tasks when performing with a partner (‘intermanual’) than with their own two hands (‘bimanual’). The generality of this ‘mode effect’ was examined using a highly practised bimanual task, shoe tying, at which participants were experts. Speed–variability correlations confirmed participants were bimanually skilled but not intermanually skilled. Contrary to results using novices, intermanual was slower, such that prior skill reverses the effect. Analyses incorporating the similarity of shoe-tying strategies across dyads implicated a perceptual rather than shared knowledge/representation basis for intermanual performance. Practice effects indicated that intermanual performance built upon prior bimanual skill, such that novel relative timings between dyads' hands must be acquired. Motor transfer effects provided support for this conclusion. During shoe tying, hands were tightly coupled in the intermanual mode due to the perceptual coupling constraints of intermanual performance. Increased coupling was correlated with slower performance. Implications for real-world tasks (e.g. surgical knot tying) are described.

Efficacy of Constraint-Induced Movement Therapy and Bimanual Training in Children with Hemiplegic Cerebral Palsy in an Educational Setting

ABSTRACTWe examined the efficacy of modified constraint-induced movement therapy (CIMT) and hand-arm bimanual intensive therapy (HABIT) in a special education preschool/kindergarten in Israel. Twelve children (1.5–7 years) with congenital hemiplegic cerebral palsy were randomized to receive modified CIMT (n = 6) or HABIT (n = 6). Occupational and physical therapists administered usual and customary care for 8 weeks; children then crossed over to receive CIMT or HABIT 2 hr/day, 6 days/week for 8 weeks from their occupational therapist. The Assisting Hand Assessment and Quality of Upper Extremity Skills Test were administered 2 months prior to the intervention, immediately before, immediately after intervention, and 6 months after the first baseline assessment. Both groups demonstrated no change during baseline and comparable improvement following CIMT and HABIT (p < .001), which was maintained at 6-month follow-up. Results suggest that modified CIMT and HABIT provided in school-based settings can lead to improvements in quality of bimanual skill and movement patterns.

Contextual interference in complex bimanual skill learning leads to better skill persistence.

The contextual interference (CI) effect is a robust phenomenon in the (motor) skill learning literature. However, CI has yielded mixed results in complex task learning. The current study addressed whether the CI effect is generalizable to bimanual skill learning, with a focus on the temporal evolution of memory processes. In contrast to previous studies, an extensive training schedule, distributed across multiple days of practice, was provided. Participants practiced three frequency ratios across three practice days following either a blocked or random practice schedule. During the acquisition phase, better overall performance for the blocked practice group was observed, but this difference diminished as practice progressed. At immediate and delayed retention, the random practice group outperformed the blocked practice group, except for the most difficult frequency ratio. Our main finding is that the random practice group showed superior performance persistence over a one week time interval in all three frequency ratios compared to the blocked practice group. This study contributes to our understanding of learning, consolidation and memory of complex motor skills, which helps optimizing training protocols in future studies and rehabilitation settings.

Comparing Changes in Bimanual Skills with Speech Production Gains Following Constraint Induced Movement Therapy in Children

Comparing Changes in Bimanual Skills with Speech Production Gains Following Constraint Induced Movement Therapy in Children

Learning to Tie Well with Others

A shoe-tying paradigm was developed to examine mode effects and motor learning functions when people are asked to handle a familiar object (e.g., tying a shoe) using an unfamiliar coordination mode (e.g., tying a shoe with another person). Dyads first tied a shoe apparatus using their own two hands (“bimanual”) for 10 trials and then tied the shoe as a dyad, each person using one hand (“intermanual”) for 20 trials. Finally, participants tied the shoe bimanually for another 10 trials. Previous research has indicated that intermanual is faster than bimanual, but those experiments examined novel tasks performed by novices. For this familiar task, results revealed that participants were significantly slower in the intermanual mode compared to either set of bimanual trials, and participants were significantly faster in the second set of bimanual trials than the first. Unlike mode effects for novel tasks with novice participants, the intermanual mode was slowest, though intermanual performance may have enhanced subsequent bimanual performance. Previous research on motor learning suggests an exponential function describes acquisition of a novel skill, whereas a power law describes persistent motor learning. Analyses revealed that dyads exhibited a power law function over both the first set of bimanual trials and the intermanual trials. That finding suggests that participants were not learning a new coordination skill in the intermanual mode but may have transferred persistent, bimanual shoe-tying skill to the novel mode. Theoretical and practical implications of acquisition of a novel coordination mode for a familiar task are described.

S14-4. Possibility of a useful intervention of exercise induced by muscle fatigue to change excitabilities of corticospinal and cortico-cortical tracts for functional recovery in neurorehabilitation

Motor learning and synaptic plasticity in the cortex are enhanced by interventions that reduce the effectiveness of GABAergic intracortical inhibition. The disinhibition of SICI by muscle fatigue could enhance synaptic plasticity and improve the consolidation of motor learning. We found that the corticospinal excitability and SICI decrease after exhaustive muscle contraction or muscle fatigue. It seems possible that decreased SICI can enhance synaptic plasticity if motor learning or skill training is combined with muscle fatigue. Interestingly, fatigue in muscles on the opposite side of the body or in lower limb muscles reduces the corticospinal excitability and disinhibit SICI in non-exercised arm or upper limb muscles during the recovery period. It is possible that muscle fatigue of the unaffected hands can act indirectly and positively on the motor function of affected hands in patients with chronic stroke and that we imagine incorporating such a technique in treatment of stroke, by inducing muscle fatigue in non-paretic lower limbs prior to neurorehabilitation of paretic upper limbs. Muscle fatigue can influence corticospinal and cortico-cortical excitability in various areas of motor cortex directly or indirectly and may be able to improve task performance in a bimanual motor skill.

Interhemispheric and intrahemispheric connectivity and manual skills in children with unilateral cerebral palsy

This study investigated patterns of motor brain activation, white matter (WM) integrity of inter- and intrahemispheric connectivity and their associations with hand function in children with unilateral cerebral palsy (CP-U). Fourteen CP-U (mean age 10.6±2.7years) and 14 typically developing children (TDC) underwent magnetic resonance imaging. CP-U underwent extensive motor evaluation. Pattern of brain activation during a motor task was studied in 12 CP-U and six TDC, by calculating laterality index (LI) and percent activation in the sensorimotor areas (around the central sulcus), and quantifying the activation in the supplementary motor area (SMA). Diffusivity parameters were measured in CP-U and eight other TDC for the corpus callosum (CC), affected and less affected cortico-spinal tracts (CST), and posterior limb of the internal capsule (PLIC). Abnormal patterns of brain activation were detected in areas around the central sulcus in 9/12 CP-U, with bilateral activation and/or reduced percent activation. More activation in areas around the central sulcus of the affected hemisphere was associated with better hand function. CP-U demonstrated more activation in the SMA when moving the affected hand compared to the less affected hand. CP-U displayed reduced WM integrity compared to TDC, in the midbody and splenium of the CC, affected CST and affected PLIC. WM integrity in these tracts was correlated with hand function. While abnormal pattern of brain activation was detected mainly when moving the affected hand, the integrity of the CC was correlated with function of both hands and bimanual skills. This study highlights the importance of interhemispheric connectivity for hand function in CP-U, which may have clinical implications regarding prognosis and management.

Substantial Generalization of Sensorimotor Learning from Bilateral to Unilateral Movement Conditions

Controversy exists regarding whether bimanual skill learning can generalize to unimanual performance. For example, some investigators showed that dynamic adaptation could only partially generalize between bilateral and unilateral movement conditions, while others demonstrated complete generalization of visuomotor adaptation. Here, we identified three potential factors that might have contributed to the discrepancy between the two sets of findings. In our first experiment, subjects performed reaching movements toward eight targets bilaterally with a novel force field applied to both arms, then unilaterally with the force field applied to one arm. Results showed that the dynamic adaptation generalized completely from bilateral to unilateral movements. In our second experiment, the same force field was only applied to one arm during both bilateral and unilateral movements. Results indicated complete transfer again. Finally, our subjects performed reaching movements toward a single target with the force field or a novel visuomotor rotation applied only to one arm during both bilateral and unilateral movements. The reduced breadth of experience obtained during bilateral movements resulted in incomplete transfer, which explains previous findings of limited generalization. These findings collectively suggest a substantial overlap between the neural processes underlying bilateral and unilateral movements, supporting the idea that bilateral training, often employed in stroke rehabilitation, is a valid method for improving unilateral performance. However, our findings also suggest that while the neural representations developed during bilateral training can generalize to facilitate unilateral performance, the extent of generalization may depend on the breadth of experience obtained during bilateral training.

The effects of task demands on bimanual skill acquisition

Bimanual coordination is essential for everyday activities. It is thought that different degrees of demands may affect learning of new bimanual patterns. One demand is at the level of performance and involves breaking the tendency to produce mirror-symmetric movements. A second is at a perceptual level and involves controlling each hand to separate (i.e., split) goals. A third demand involves switching between different task contexts (e.g., a different uni- or bimanual task), instead of continuously practicing one task repeatedly. Here, we studied the effect of these task demands on motor planning (reaction time) and execution (error) while subjects learned a novel bimanual isometric pinch force task. In Experiment 1, subjects continuously practiced in one of the two extremes of the following bimanual conditions: (1) symmetric force demands and a perceptually unified target for each hand or (2) asymmetric force demands and perceptually split targets. Subjects performing in the asymmetric condition showed some interference between hands, but all subjects, regardless of group, could learn the isometric pinch force task similarly. In Experiment 2, subjects practiced these and two other conditions, but in a paradigm where practice was briefly interrupted by the performance of either a unimanual or a different bimanual condition. Reaction times were longer and errors were larger well after the interruption when the main movement to be learned required asymmetric forces. There was no effect when the main movement required symmetric forces. These findings demonstrate two main points. First, people can learn bimanual tasks with very different demands on the same timescale if they are not interrupted. Second, interruption during learning can negatively impact both planning and execution and this depends on the demands of the bimanual task to be learned. This information will be important for training patient populations, who may be more susceptible to increased task demands.

A Low-Fidelity Simulator for Nasendoscopy Training

A Low-Fidelity Simulator for Nasendoscopy Training

Testing Multiple Coordination Constraints with a Novel Bimanual Visuomotor Task

The acquisition of a new bimanual skill depends on several motor coordination constraints. To date, coordination constraints have often been tested relatively independently of one another, particularly with respect to isofrequency and multifrequency rhythms. Here, we used a new paradigm to test the interaction of multiple coordination constraints. Coordination constraints that were tested included temporal complexity, directionality, muscle grouping, and hand dominance. Twenty-two healthy young adults performed a bimanual dial rotation task that required left and right hand coordination to track a moving target on a computer monitor. Two groups were compared, either with or without four days of practice with augmented visual feedback. Four directional patterns were tested such that both hands moved either rightward (clockwise), leftward (counterclockwise), inward or outward relative to each other. Seven frequency ratios (3∶1, 2∶1, 3∶2, 1∶1, 2∶3. 1∶2, 1∶3) between the left and right hand were introduced. As expected, isofrequency patterns (1∶1) were performed more successfully than multifrequency patterns (non 1∶1). In addition, performance was more accurate when participants were required to move faster with the dominant right hand (1∶3, 1∶2 and 2∶3) than with the non-dominant left hand (3∶1, 2∶1, 3∶2). Interestingly, performance deteriorated as the relative angular velocity between the two hands increased, regardless of whether the required frequency ratio was an integer or non-integer. This contrasted with previous finger tapping research where the integer ratios generally led to less error than the non-integer ratios. We suggest that this is due to the different movement topologies that are required of each paradigm. Overall, we found that this visuomotor task was useful for testing the interaction of multiple coordination constraints as well as the release from these constraints with practice in the presence of augmented visual feedback.

The Pirate Group Intervention Protocol: Description and a Case Report of a Modified Constraint‐induced Movement Therapy Combined with Bimanual Training for Young Children with Unilateral Spastic Cerebral Palsy

The purpose of this article was to describe a child-friendly modified constraint-induced movement therapy protocol that is combined with goal-directed task-specific bimanual training (mCIMT-BiT). This detailed description elucidates the approach and supports various research reports. This protocol is used in a Pirate play group setting and aims to extend bimanual skills in play and self-care activities for children with cerebral palsy and unilateral spastic paresis of the upper limb. To illustrate the content and course of treatment and its effect, a case report of a two-year-old boy is presented. After the eight-week mCIMT-BiT intervention, the child improved the capacity of his affected arm and hand in both quantitative and qualitative terms and his bimanual performance in daily life as assessed by the Assisting Hand Assessment, ABILHAND-Kids, Video Observations Aarts and Aarts Module Determine Developmental Disregard, Canadian Occupational Performance Measure and Goal Attainment Scaling. It is argued that improvement of affected upper-limb capacity in a test situation may be achieved and retained relatively easily, but it may take a lot more training to stabilize the results and automate motor control of the upper limb. Future studies with groups of children should elaborate on these intensity and generalization issues.

Assessing bimanual performance in young children with hemiplegic cerebral palsy: a systematic review

This systematic review investigated the availability of assessment tools to evaluate bimanual skills in young children (< or = 3y) with hemiplegic cerebral palsy. Evidence for validity, reliability, and clinical utility of the identified instruments was sought. Ten electronic databases and grey literature were searched (earliest 1806) to February 2009 to identify articles that met criteria related to the child's age and diagnosis, and included a discrete bimanual assessment. Further searches for evidence of psychometric properties of each identified assessment were undertaken. For quality criteria, we evaluated the internal validity of each study and appraised the validity and reliability of identified assessments. From 1435 papers retrieved, 15 were eligible for inclusion, and 11 assessments of bimanual performance were identified. Ten assessments had inadequate evidence for reliability and validity. Only the Assisting Hand Assessment had evidence for reliability and validity for its intended purposes. Reliability and validity are fundamental considerations when developing or selecting assessments. Additional considerations for assessing young children include the following: (1) standardized administration and scoring; (2) items that capture the complexity of bimanual behaviour; and (3) protocols and items targeted within a small age range to meet specific developmental needs. A validated assessment of younger infants is needed to support early intervention during this period of rapid brain development.

Two hands are better than one: bimanual skill development in children with hemiplegic cerebral palsy

Children with hemiplegic cerebral palsy (CP) have unilateral sensory and motor impairments that may lead to developmental disuse of the affected upper extremity and ⁄or reduced ability to use the affected upper extremity during tasks requiring two hands. Since many functional activities do require the coordinated use of both hands (e.g. dressing, self-care), these impairments may dramatically impact daily function. Thus, understanding the development of bimanual upper extremity use in this population is important, however, such knowledge is largely lacking. In an exciting and ambitious new study, Holmefur and colleagues at the Karolinska Institute report the findings of a prospective longitudinal study of bimanual upper extremity use in 43 children with hemiplegic CP. Children were followed on average 4 and a half years using the Assisting Hand Assessment (AHA), a Rasch-based measure that effectively describes how the affected upper extremity is used as a non-dominant assist during bimanual activities. Overall they found that bimanual proficiency did improve during the course of development, but that the developmental rate and subsequent plateau depended on the initial score at 18 months of age. Specifically, children with higher (better) AHA scores in early childhood developed bimanual skills faster and reached their limit earlier than children with lower AHA scores. Interestingly, the development of bimanual upper extremity use differs from that of gross motor activities, where mildly affected children reach their limit later. Thus importantly, gross motor function cannot be used as a proxy for predicting bimanual hand use. While this is not the first study of hand development in children with CP, this is the first study of bimanual hand use using a standardized measure. The findings of the AHA differ from those of the Manual Ability Classification System in the same children, which is in line with the other developmental studies to date indicating that various aspects of hand development progress with different time courses and rates. It is at first disheartening to think that prognosis may be predetermined early on. However, the ‘glass half-full’ view is that this information may be clinically important for treatment decisions such as when and how often to engage children in conventional treatments and intensive therapies such as constraint-induced movement therapy and bimanual training. Holmefur et al. have taken an important step in understanding the ontology of hand function in children with hemiplegic CP. However, it should be noted that the development of hand function in children with hemiplegic CP younger than the study participants (<18mo) is largely unknown. Being able to detect early signs of impairments and relate them to subsequent development is critical since hemiplegia is typically diagnosed between 4 and 6 months of age, only after one upper extremity begins to demonstrate visible impoverished movement. This is correlated with the simultaneous strengthening of ipsilateral projections and retraction of contralateral projections of the corticospinal tract to the spinal cord. Using an animal model of hemiplegia, Martin et al. at Columbia University have shown that such structural changes in neural substrates are exacerbated by reduced activity in the contralateral motor cortex, associated with the emerging disuse of the affected extremity. Conversely, such damage can be circumvented if sufficient activity is provided at a young enough age. Thus, objective quantification and predictive development of hand function at an early age is imperative in order to begin targeted treatment to break this vicious cycle whereby

Cortico-spinal synchronization reflects changes in performance when learning a complex bimanual task

Motor performance is accompanied by neural activity in various cortical and sub-cortical areas. This intricate network has to be delicately orchestrated. We analyzed the role of beta synchronization in motor learning using magneto-encephalography combined with electromyography. Cortico-spinal synchronization in the beta band was found to be of particular importance in establishing bimanual movement patterns in the context of a 3:2 polyrhythmic (isometric) force production task. Its dynamics correlated highly with the learning of this complex bimanual motor skill. We submit that the cortical dynamics entrains the spinal motor system by which cortico-spinal beta synchrony serves higher-level motor control functions as primary means of information transfer along the neural axis.

The functional relevance of interhemispheric premotor-motor connectivity for bimanual movements in young and elder healthy subjects

Introduction: With healthy aging, the motor cortical network subserving the execution of voluntary movements is less lateralized. However, aging effects on the temporal dynamics of interhemispheric connectivity patterns and the impact of connectivity changes on bimanual skills are not completely understood. In the present study we evaluated interhemispheric interactions between premotor and primary motor cortex and their functional relevance for bimanual movements in elderly compared to young subjects.

Severe generalized neuropathy in an 18-year-old patient with hereditary sensory-motor polyneurpathy (HMSN) type 1 treated with vincristine due to acute leukemia

We report about the 18-year-old male patient with hereditary sensory-motor polyneuropathy (HMSN) type 1. Despite a positive family history, the patient had no complaints. He was able to walk, to run and even to jump. He was diagnosed with HMSN type 1 when he went through chemotherapy due to an acute leukemia in November 2007. After the third dose of vincristine it came to a rapid neurological deterioration with the loss of the ability to walk and to stand, the bimanual function and a general weakness due to a particular sensitivity to vincristine, which was abandoned straight afterwards. In the end, the patient was only lying in bed. Then a genetic analysis was done due to the high frequency of HSMN type 1 in the family and a duplication on chromosome 17p11.2-p12 was found in the patient, which confirmed the diagnosis. During the rehabilitation therapy which was started parallel to the chemotherapy, the patient was not only enabled to walk a distance of 1500m without any devices, but also his bimanual skills and his ability to write were acquired. At discharge, the patient was again fully independent in his activities of daily life. Although he underwent a new chemotherapy treatment and suffered from pneumonia and aspergillosis of the lung, which led to a lobectomy of the right side, it did not come to a deterioration or even loss of the motoric skills.