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Biomedical subjects

L Fetters

Publications and source records attributed to L Fetters.

9 recordsLinked to original sources
PubMed2001

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.

Adolescent↗
PubMed1996

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.

Adolescent↗
PubMed1996

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.

Adult↗
PubMed1991

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.

Cerebral Palsy↗
PubMed1990

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.

Arm↗
PubMed1987

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.

Journal Article↗
PubMed1981

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.

Child, Preschool↗