Contribution of spinal segments to control of posture during typical and atypical development
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Date
2010-03
Authors
Saavedra, Sandra Lee, 1952-
Journal Title
Journal ISSN
Volume Title
Publisher
University of Oregon
Abstract
Trunk control is critical for all functional movement, yet little is known about the development of trunk stability. Previous research considered the trunk to be one rigid segment ignoring the complexity of multiple spinal segments. In healthy adults spinal control is so well orchestrated that this assumption is reasonable; however during development and more specifically in pathological conditions in which spinal control is immature or compromised, this assumption may prevent accurate analysis and/or treatment of the condition.
This dissertation investigates the mechanisms used by typical infants in gaining postural control of spinal segments for independent sitting. Infant data were compared to data from children with cerebral palsy (CP). The contribution of spinal segments was assessed by stabilizing the trunk in vertical alignment with four levels of support (axillae, mid-ribs, waist or hips). Documentation of postural sway of the head reflected the motor control available in the free segments of the spine. Kinematic data were collected bimonthly from 3 to 9 months of age in typically developing infants and 3-4 times over a 4 month time span in children with CP.
The infants' response to external support changed in a non-linear, stage-like fashion as they transitioned from immature to mature spinal control. Head stability emerged first at higher levels of trunk support and gradually progressed in a cephalocaudal pattern to lower levels of support. Emergence of functional sitting was associated with mastery of postural control in the lower lumbar and pelvic regions of the spine. The severity of CP was related to the level of spinal control achieved. Children with severe CP had control in the cervical or upper thoracic spine while those with moderate CP had control into the mid to lower thoracic spine. In addition, behavioral patterns seen in children with CP were consistent with developmental stages seen in typical infants during acquisition of vertical alignment. These findings challenge the existing clinical practice of evaluating and treating the trunk as a single segment, offer intermediate measures of progression of spinal control and propose that a more specific approach may create the foundation for improved motor outcomes in pathological populations.
Description
xviii, 125p. : ill. (some col.) A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.
Keywords
Spinal segments, Posture, Cerebral palsy, Head control, Physical therapy, Kinesiology, Physiology