Catherine A. Trombly

A kinematic study of contextual effects on reaching performance in persons with and without stroke: influences of object availability.

OBJECTIVE To examine the effects of context on reaching performance in neurologically impaired and intact populations. Context was varied by the presence or absence of objects used to complete a task. DESIGN A counterbalanced repeated-measures design. SETTING A motor control laboratory in a university setting. PARTICIPANTS Fourteen persons with stroke and 25 neurologically intact adults. INTERVENTIONS Each participant was tested under two conditions: the presence of the object, in which the participant reached forward with the impaired arm (or corresponding arm) to scoop coins off the table into the other hand; and the absence of the object, in which the participant reached forward to the place where the coins would be placed in the condition of object present. MAIN OUTCOME MEASURES Kinematic Variables of movement time, total displacement, peak velocity, percentage of reach where peak velocity occurs, and movement units (derived from acceleration data) for reaching tasks. RESULTS The condition of using real objects elicited kinematically better performance of reaching movements than the condition of performing movements without relevant objects present. Better performance was reflected by shorter movement time, less total displacement, higher peak velocity, greater percentage of reach where peak velocity occurs, and fewer movement units. CONCLUSION The results of this study showed that the condition of object present elicited better performance of movements represented by kinematic variables than the condition of object absent. The clinical implication is that the use of real and functional objects might be an effective way of facilitating efficient, smooth, and coordinated movement with the impaired arm in persons with stroke. This study, however, should be replicated and extended to confirm the validity of its findings and to allow for generalization in various functional activities.

Predicting elementary school participation in children with disabilities

OBJECTIVE To identify predictors of participation in school activities from two sets of functional variables using classification and regression tree analysis. DESIGN Relational study. PARTICIPANTS A nationwide sample of 341 children with various disabling conditions, including physical and cognitive/behavioral types of impairment and various severity levels. Children attended public elementary school in 40 states in the United States. MAIN OUTCOME MEASURE Overall participation in elementary school, combining childrens participation in six different environments (transportation, transitions, classroom, cafeteria, bathroom, and playground), as measured by the newly developed School Function Assessment. The children were dichotomized into full (n = 117) and limited (n = 224) participation categories. RESULTS Two classification trees were developed identifying a small set of predictors from variables measuring performance of functional tasks and discrete activities. Final predictive models included physical and cognitive-behavioral variables, suggested important interactions among predictors, and identified meaningful cut-off points that classified the sample into the outcome categories with about 85% accuracy. CONCLUSIONS Limited participation was predicted by information about childrens physical capabilities. Full participation was predicted by a combination of physical and cognitive-behavioral variables. Findings underscore the relative utility of functional performance compared with impairment information to predict the outcome, and suggest pathways of influence to consider in future research and intervention efforts.

Effect of one single auditory cue on movement kinematics in patients with Parkinson's disease.

Ma HI, Trombly CA, Wagenaar RC, Tickle-Degnen L: Effect of one single auditory cue on movement kinematics in patients with Parkinson’s disease. Am J Phys Med Rehabil 2004;83:530–536. Objective:The purpose of this study was to determine whether one single auditory cue affected movement kinematics of more than one step in a sequential upper limb task in patients with Parkinson’s disease. Design:A counter-balanced repeated-measures design was employed. A total of 16 male patients with Parkinson’s disease and 16 age-matched male and female controls performed the task under two conditions. In the signal-present condition, the participants were instructed to start the movement when they heard a bell ring. In the signal-absent condition, there was no bell ringing, and they were told to start the movement when they were ready. Kinematic performances for the first two movement segments (i.e., reaching for the pen and bringing the pen to the paper) were compared between conditions. Results:The results indicated that the presence of the single auditory cue affected movement kinematics of the patients with Parkinson’s disease but not that of the controls. When given external cueing, the patients elicited faster, more forceful, more efficient, more stable, but less smooth movement. Conclusions:The results suggest that therapists should provide external cues according to their treatment goals. In addition, researchers should be aware of the influence of start signals when designing subsequent experiments.

Effects of left-sided movements on line bisection in unilateral neglect

Thirteen patients with left neglect performed line bisection under four conditions: no cue, visual cueing involving the report of a digit placed at the left end of the line, circling the left-end digit, and digit circling plus tracing of the line with the right index finger from its left end to its midpoint before bisection. Digit circling plus finger tracing was unequivocally more effective in reducing left neglect than digit circling alone, which was in turn more effective than visual cueing; indeed, digit circling with tracing completely abolished the rightward bisection bias. Thus continuously directing visuomotor control to the left side of the line (even with the right hand) until bisection is performed reduces neglect more than only requiring patients to attend to left-sided visual cues. The facilitatory effects of the cueing procedures may reflect their differential efficacy in constraining as well as attracting attention and action to the left part of the target line. These findings have implications for neglect rehabilitation.

Kinesthetic recall of children with athetoid and spastic cerebral palsy and of non-handicapped children.

Twenty‐four children with spastic or athetoid quadriplegic cerebral palsy were paired according to severity of motor disability and age, then matched with 12 non‐handicapped children of similar ages. The children were tested with a standard kinesthesiométér and two kinds of scores were recorded. Absolute Error scores reflected the childrens deviation from the target and Total Movement scores reflected their over‐all range of movement. There were significant differences between groups in Absolute Error scores, with the cerebral‐palsied children performing worse than the controls and the spastic children worse than the athetoid children. All three groups tended to underestimate the targets and there were no significant differences in Total Movement scores.

Effects of Object Affordances on Movement Performance: A Meta-Analysis

It is suggested that an effective method of re-establishing function is to give patients with brain lesions tasks that involve reaching for or reaching-to-grasp objects [1, 2]. This viewpoint is reflected in the model of occupation [3, 4] showing that a materials-based form of occupation (i.e., the use of real objects) could elicit better occupational performance than other types of occupational form such as imagery-based occupation and rote exercise. The notion of beneficial effects derived from materials-based occupation was supported by a previous meta-analysis [5]. The finding of this earlier meta-analysis holds promise for further investigation into how the use of objects can contribute to changes in motor performance. This meta-analytic review investigates this possibility and synthesizes the findings of the studies investigating the effects of affording objects (i.e., object affordances) on motor performance. The results of this meta-analysis show a moderate relationship between object affordances ...

Effects of Lateralized Tasks on Unilateral Neglect after Right Cerebral Vascular Accident

This study examined whether activities designed to stimulate the right hemisphere of the brain resulted in decreased neglect in patients with right cerebral vascular accident (CVA) and unilateral neglect (UN) and, conversely, whether activities designed to stimulate the left hemisphere resulted in increased left neglect. An alternating treatment, single subject design was used with five subjects, ages 57 to 74, who demonstrated neglect on both the Schenkenberg Line Bisection Test and the behavioral subtest of the Behavioral Inattention Test. Each subject received 8 days of baseline measures (Schenkenberg Line Bisection Test) and 10 days of treatment, during which the subjects were alternately engaged in the groups of tasks intended to arouse a particular hemisphere, followed by six to eight baseline measures. Line bisection scores were taken after each treatment. The significance of change in UN after either group of activities was determined by visual inspection and semi-statistical analysis using the two standard deviation band method. The findings did not support the hypotheses. Two subjects demonstrated no significant change after either treatment phase; one subject showed a significant decrease in neglect after both phases of treatment; one subject showed a significant decrease in neglect after activities designed to stimulate the right hemisphere but no change after activities to facilitate the left hemisphere; and one subject showed a significant increase in neglect after both types of treatment. Results are discussed in terms of severity of impairment, fatigue effect, spontaneous recovery, and the adequacy of the tasks to differentially activate a single hemisphere.

Context and Goal-Directed Movement: The Effect of Materials-Based Occupation

This exploratory study investigated whether materials-based occupation elicited significantly better movement organization in the ipsilateral arm following left hemisphere stroke than imagery-based occupation. Five persons with left cerebrovascular accident (CVA) and 5 control participants performed functional tasks (e.g., slicing bread) under four conditions. During the materials-based condition, needed tools and objects were available for task completion. In the three imagery-based conditions, either the tool or object of the tools action was present, or the participant was asked to simulate the task without objects. For all tasks, motor performance of persons with and without CVA was significantly more direct and less forceful during materials-based occupation. Movement time was significantly faster under this condition in three of the four tasks. The relationship between motor performance and context was reinforced. Persons with and without CVA adjusted their motor actions according to the affordances offered during materials-based occupation.

Grasping in Children with and without Cerebral Palsy: A Kinematic Analysis

This study investigates how children with and without cerebral palsy (CP) adapt their hand grasp to changes in the size of the object involved in a prehension task. Specific questions include: does the maximum hand aperture (MHA) change synchronously with the size of the object to be grasped? Does the shape of the hand aperture form during the transportation phase to the object? In what way do children with CP differ from typically developing children? Thirteen children with spastic CP and 13 children with typical development participated in this study. Participants were engaged in a game that involved reaching to grasp wooden spheres of two sizes. Grasping movements were measured kinematically using a three-dimensional movement analysis system, Optotrak. Children in both groups exhibited larger hand apertures when grasping large objects than when grasping smaller objects. Furthermore, children in both groups reached their MHA earlier during the transport phase when grasping the smaller object than when g...

Proximal and Distal Function in Children with and without Sensory Integrative Dysfunction: An E.M.G. Study

Proximal shoulder muscle activity was studied in normal children and children with sensory integrative dysfunction (n = 16), using electromyography. The data revealed significant differences between the groups in the amount of muscle activity produced during pencil tasks demanding movement and control of the distal part of the extremity, and during static weight bearing and developmental postures. No significant correlations were found between the degree of skill in distal control tasks and the amount of activity of proximal stabilizer muscles. This finding presents a challenge to the therapeutic premise that distal control is dependent on proximal stability. Implications for treatment of children with sensory integrative dysfunction, and for further research, are discussed.