Using Contingent Reinforcement to Augment Muscle Activation After Perinatal Brachial Plexus Injury: A Pilot Study.

AIM: Examine the feasibility of increasing muscle activation with electromyographically (EMG)-triggered musical-video as reinforcement for children with perinatal brachial plexus injury (PBPI). METHODS: Six children with PBPI (9.3 ± 6.3 months; 5 female, 1 male) and 13 typically developing (TD) controls (7.8 ± 3.5 months; 4 female, 9 males) participated. The left arm was affected in 5/6 children with PBPI. We recorded the integral (Vs) of biceps activation with surface EMG during two conditions per arm in one session: (1) 100 second (s) baseline without reinforcement and (2) 300 s reinforcement (musical-video triggered to play with biceps activation above threshold [V]). We examined the relation between the mean integral with reinforcement and hand preference. RESULTS: Mean biceps activation significantly increased from baseline in the affected arm of the group with PBPI by the 2nd (p < .008) and 3rd (p < .0004) 100 s intervals of reinforcement. Six of 6 children with PBPI and 12/13 TD controls increased activation in at least one arm. A lower integral was linked with hand preference for the unaffected right side in the PBPI group. CONCLUSION: This study supports contingent reinforcement as a feasible method to increase muscle activation. Future work will examine training dose and intensity to increase arm function.

Suppression of rupture in thin, nonwetting liquid films.

Stabilization against the rupture and breakup of thin, nonwetting liquid films spread on surfaces is generally sought by modification of equilibrium interfacial properties. A mechanism for suppressing rupture in such films that uses surface-attached polymers togetherwithfree chains in the bulk of the film is reported. Films of an oligostyrene liquid, which rupture within several minutes when spread on a silicon wafer, may be stabilized for many months by a polystyrene brush attached to the substrate, together with some free polystyrene in the liquid. The effect may arise from entanglements of the free chains with the immobilized brush.

Polymers: synthesis and characterization of extremely high-molecular-weight polystyrene.

Polystyrenes with molecular weights up to 44 x 10(6) grams per mole have been characterized by light-scattering and equilibrium ultracentrifugation methods. The Mark-Houwink equation, which relates the molecular weight and the intrinsic viscosity of flexible polymers, can be used only if the measurements are made in a theta solvent at the theta temperature.

Complete wetting from polymer mixtures.

Coexisting polymer phases are characterized by very small interfacial energies, even well below their critical solution temperature. This situation should readily lead to the exclusion of one of the phases from any interface that favors the other. Such complete wetting behavior from a binary mixture of statistical olefinic copolymers is reported. By means of a self-regulating geometry, it is found that the thickness of a wetting layer of one of the phases at the polymer-air interface, growing from the other coexisting phase, attains macroscopic dimensions, increasing logarithmically with time. These results indicate that binary polymer mixtures could be attractive models for the study of wetting phenomena.

The effect of exercise intervention on daily life activities and social participation in individuals with Down syndrome: A systematic review.

BACKGROUND: Few systematic reviews have looked at the effect of exercise intervention on activities of daily living and social participation in individuals with Down syndrome (DS) across the lifespan. AIMS: To evaluate the research on the effectiveness of exercise intervention on daily life activities and participation in individuals with DS. METHODS AND PROCEDURES: Studies are from six electronic databases (CINHAL, Cochrane, ERIC, PEDro, PubMed, and PsycINFO) from 1987 to 2016. Nineteen studies met inclusion criteria. American Academy for Cerebral Palsy and Developmental Medicine (AACPDM) levels of evidence and an Intervention Clinical Appraisal Form were used to independently assess study quality and outcome measures coded using the International Classification of Functioning, Disability, and Health (ICF). OUTCOMES AND RESULTS: There were 525 participants, age range, 3-65.5 years. The quality of the studies ranges from AACPDM Level I-IV and Intervention Clinical Appraisal Form scores of 4 to 10. A meta analysis was not conducted due to heterogenity of studies. CONCLUSIONS AND IMPLICATIONS: Exercise intervention was supported for both daily life activities and participation. Rigorous research studies are needed across the lifespan using objective outcome measures for ICF levels.

Methacholine challenge test.

Methacholine challenge has been proposed as a diagnostic test in situations where clinical asthma is suspected but reversible airway obstruction cannot be demonstrated spirometrically. Methacholine challenge was used in 14 patients with suspected asthma and five normal controls. Eight individuals (six patients and two controls) had a reduction in the forced expiratory volume at 1 s (FEV1) of 20% or more with 100 inhalation units (IUs) of methacholine; seven additional individuals (six patients and one control) met one or more of the American Thoracic Society's criteria for a positive bronchoprovocation test; and four individuals (two patients and two controls) were not sensitive to methacholine by any criteria. The diagnosis of asthma can be excluded if methacholine does not induce reversible obstruction. However, provocation of reversible obstruction with methacholine is not specific for asthma. More stringent criteria, such as reduction of FEV1 by 20% by 20 IUs of methacholine, would be less sensitive but more specific for asthma.

Neuromotor development of cocaine-exposed and control infants from birth through 15 months: poor and poorer performance.

OBJECTIVE: The objective of this study is to describe the longitudinal course of motor development of a group of infants exposed to cocaine in utero and an unexposed control group. METHODS: Subjects included 28 in utero-exposed infants and 22 unexposed infants matched for race, income of the family, and mother's educational level. Infants were evaluated at 1 month with the Alberta Infant Motor Scale (AIMS), at 4 months with the AIMS and Movement Assessment of Infants (MAI), at 7 months with the AIMS and MAI, and at 15 months with the Peabody Developmental Motor Scales (PDMS). RESULTS: At 4 months, compared with the unexposed infants, a significantly larger proportion of the exposed infants fell below the 50th percentile on the AIMS and had greater proportion of suspicious risk scores on the MAI. At 7 months infants in the exposed group had lower AIMS and MAI scores than the control group. There was no difference between groups on the motor scales at 1, 4, or 15 months. At all ages more infants in both groups scored significantly less than the expected norms on all scales. Performance was unrelated to a cumulative risk index made up of demographic, medical, and social factors. Almost all subjects had risk scores that placed them at extremely high levels of risk. Performance may have been related to a difference in weight between groups at 7 months and to decreasing weights for both groups by 15 months. CONCLUSION: In utero cocaine exposure has a significant, although relatively small, effect on infant motor performance late in infancy. However, regardless of exposure status, these infants had poor performance that may be accounted for by a heavy accumulation of risk factors associated with poverty.

Measurement and treatment in cerebral palsy: an argument for a new approach.

This article describes the need for a shift in our therapeutic strategies for patients with cerebral palsy. Changes in functional abilities must be stressed in therapy. Coincident with this emphasis must be the development of functional assessments to be used when documenting intervention outcomes. Research on functional arm movement using kinematic analysis is described for this patient group.

Object permanence development in infants with motor handicaps.

This study was an investigation of the effects of a motor handicap on the development of object permanence in the young child. Motor abilities were evaluated for 12 infants aged 13 to 29 months. Based on this evaluation, the children were described as manipulators or nonmanipulators in reference to their upper extremity skills. Their stage of object permanence was assessed using traditional and nontraditional assessments. Heart rate and visual tracking were recorded during the nontraditional assessment. Heart rate did not significantly relate to visual fixation or search response. There was, however, a significant difference (p less than .02) between stage achievement with traditional testing and age-appropriate levels. There was no significant difference between the nontraditional assessment and the age-appropriate levels. In addition, there was no significant difference in the development of object permanence between infants described as manipulators and those described as nonmanipulators. The last two findings suggest that infants with motor handicaps may develop object permanence at the expected ages, according to a nontraditional assessment.

The effects of neurodevelopmental treatment versus practice on the reaching of children with spastic cerebral palsy.

BACKGROUND AND PURPOSE: Children with cerebral palsy (CP) are frequently referred for physical therapy, yet the effectiveness of treatment has not been well-documented. In the relatively few available studies, outcomes are divided between support and lack of support for treatment. The purpose of this research was to document and evaluate the effects of a physical therapy program on the reaching movements of children with spastic CP. SUBJECTS: Eight children with CP, 10 to 15 years of age, were treated daily for 5 days with a version of neurodevelopmental treatment (NDT) and for 5 days with practice of reaching tasks. METHODS: Changes in movement time, path, and smoothness of reach were quantified and described using kinematic analysis. Results. There were no differences in any of the variables following 5 days of NDT. There was a difference in movement time, but in no other variables, following 5 days of practice. When time in treatment, rather than type of treatment, was the independent variable, the data showed changes. Both movement time and movement units were reduced following 5 days of treatment. Movement time, movement units, and displacement, but not reaction time, were reduced following the completion of both types of treatment. CONCLUSION AND DISCUSSION: The two treatments in combination may be necessary to achieve these results. Alternatively, either treatment type alone, when given for at least 2 weeks, may produce similar results.

Quantification of control: a preliminary study of effects of neurodevelopmental treatment on reaching in children with spastic cerebral palsy.

The effects of neurodevelopmental treatment on reaching in children with spastic quadriplegia were studied using a method of analysis to quantify the qualitative term "smoothness." Hand position in three-dimensional space was recorded during a simple reaching task using the WATSMART (Waterloo Spatial Motion Analysis and Recording Technique) system in conjunction with videotaping. The number of accelerations and decelerations (movement units) were measured in addition to movement time, distance of path (directedness), and associated reactions. Each subject performed several reaches before and following one treatment session. Following treatment, reaches were significantly faster, smoother (fewer movement units), and more mature. This study supports the hypotheses that neurodevelopmental treatment can produce immediate changes in the kinematic properties of reaching and that kinematic data can be used to quantitatively describe components of movement (eg, smoothness) that have traditionally been described qualitatively.

Quantitative assessment of infant reaching movements.

We have identified a fundamental property of human motor behavior as a tight coupling of the curvature-speed relationship in the reaching movements of 5- to 9-month-old infants. This relationship termed a movement unit, occurs regardless of the distance of duration of the reach and in spite of the developmental change that occurs in grasping during this period. Movement unit durations are tightly clustered around 200 ms regardless of overall duration or distance or the position of the unit in the reach. The curvature-speed coupling has been identified by others in adult reaching and handwriting. Models of biological motor control must account for this invariant relationship.

A dynamical model of locomotion in spastic hemiplegic cerebral palsy: influence of walking speed.

OBJECTIVE: The objective of this study was to assess the capability of an escapement-driven inverted pendulum with springs and damping model to estimate the effects of impairments (e.g. spasticity, muscle weakness) on the dynamics and patterns of locomotion of children with spastic cerebral palsy. METHODS: Kinematic data of six children with spastic hemiplegic cerebral palsy and six matched, typically developing children were collected at five different self-selected overground walking speeds ('very slow' to 'very fast'). Changes in forcing, stiffness and gravitational potentials were estimated during the stance phase of each leg according to the model's equation of motion. RESULTS: Significantly greater stiffness and decreased forcing was observed in the more affected limbs of children with spastic hemiplegic cerebral palsy and compared to typically developing peers. The forcing term of the non-affected limb was greater than that of the matched typically developing children. CONCLUSIONS: Results support the claim that disabled individuals with losses in dynamic resources (stiffness, muscle forcing capability) exploit and develop the remaining resources in their adapted gait patterns. It was suggested that clinical interventions aimed at normalizing a gait pattern may be contraindicated, and that rehabilitation might be more effective if focused at the level of dynamics. RELEVANCE: Pattern formation is seen as an optimal solution based on the individuals' action capabilities and dynamic properties under environmental and task demands. This perspective could lead to the development of interventions that address these dynamic variables with the objective of improving the functional capabilities of children with cerebral palsy.

Cost-effective syphilis screening in military recruit applicants.

A cost-effectiveness analysis of syphilis screening was performed. Strategies included no screening, universal testing at military entrance processing stations, universal testing at basic training centers, and contracting centralized screening. Probabilities derived from data retained on recruit applicants from 1989 through 1991 (N = 1,588,143) and from the published literature were used. Cost estimates were derived from costs incurred by the military and costs projected from implementing new strategies. Sensitivity analyses were performed. Modifying the existing contract for human immunodeficiency virus screening to include syphilis screening would maximize the effectiveness of screening at a cost to the Department of Defense of $9.52 per additional year of service received. The no-screening option was significantly more cost-saving than the current method of testing. Syphilis is rare and treatable, and individuals with syphilis will be identified by other means in many cases. Syphilis screening of recruit applicants at the military entrance processing stations should cease, saving the military $2,541,000 per year.

An in situ study of the t-butyllithium initiated polymerization of butadiene in d-heptane via small angle neutron scattering and 1H-NMR.

We present a combined 1H-NMR and small angle neutron scattering in situ study of the anionic polymerization of butadiene using t-butyllithium as the initiator. Both initiation and propagation phases were explored. This combined approach allows the structural and kinetic characteristics to be accessed and cross compared. The use of the D22 instrument (ILL Grenoble) permits the attainment of Q approximately equal to 2 x 10(-3) A. This, in turn, led to the identification of coexisting large-scale and smaller aggregates during all stages of the polymerization. The smaller aggregates contain most of the reacted monomers. Their structure changes from high functionality wormlike chains at early stages of the reaction to starlike aggregates where the crossover occurs at a degree of polymerization of approximately equal to 40. The initiation event involved these small, high functionality (approximately equal to 120) aggregates that apparently consisted of cross-associated t-butyllithium with the newly formed allylic-lithium head groups. As the initiation event progressed the initiation rate increased while the functionality of these small aggregates decreased and their size increased. Propagation, in the absence of initiation, was found to have a rate constant that was molecular weight dependent. At approximately 11 kg/mol the measured polymerization rate was found to increase while no further structural changes were seen.

Self-Optimization of Walking in Nondisabled Children and Children With Spastic Hemiplegic Cerebral Palsy.

Children voluntarily adopt a frequency and movement pattern for walking. The force-driven harmonic oscillator (FDHO) model was used in this study for accurate prediction of the preferred walking frequency of nondisabled children and children with spastic hemiplegic cerebral palsy. Four potential optimality criteria with which the preferred walking pattern was forced to comply were examined: minimization of physiological costs, maximization of mechanical energy conservation, minimization of asymmetry in lower limb movements and minimization of variability of interlimb and intralimb coordination. Age and gender-matched nondisabled children (n = 6) and children with spastic hemiplegic cerebral palsy (n = 6) were tested under six frequency conditions of walking at a constant speed on a treadmill. For the nondisabled children, the results indicated that their preferred walking frequency could be accurately predicted by the FDHO model. They freely adopted a walking pattern that minimized physiological costs, asymmetry, and variability of inter- and intralimb coordination. For the children with spastic hemiplegic cerebral palsy, the prediction of preferred overground walking frequency required that the FDHO model be modified to account for muscle mass and leg length discrepancies between limbs and increased stiffness. Most of the children achieved the same optimality goals as the nondisabled when walking at the preferred frequency. However, the children were found to use different mechanisms to attain these goals: for example, a steeper increase observed in physiological cost at higher frequencies; a lowered center of gravity of the body, which allowed for angular symmetry; and greater variability of between-joint coordination in the nonaffected limb and less variability in the affected limb.