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 Title: Horizontal plane head and trunk motion during locomotion Author(s): Cromwell, Ronita Lee Doctoral Committee Chair(s): Carlton, Les G. Department / Program: Kinesiology Discipline: Kinesiology Degree Granting Institution: University of Illinois at Urbana-Champaign Degree: Ph.D. Genre: Dissertation Subject(s): Biology, Neuroscience Applied Mechanics Education, Physical Abstract: Head stability is essential for maintaining gaze and postural orientation of the body. This study examined head and trunk movements in the horizontal plane during four walking tasks. Ten subjects performed the following tasks: normal walking (normal), walking with arm swings at twice the normal frequency (frequency), walking with large amplitude arm swings (amplitude), and walking with arm swings 180$\sp\circ$ out of phase (phase). Two subjects were analyzed separately as they removed their corrective eyeglasses to participate. Head and trunk angular velocities were recorded using angular rate sensors attached to these segments. Position information was obtained through integrating velocity data. Coherence analyses examining the relationship of trunk velocity to head on trunk velocity showed values near 1 for all frequencies in each condition with few exceptions. This indicates a strong relationship between trunk and head movements during all tasks. Standard deviations of position were examined to determine relative stability of head and trunk segments with respect to normal. Multivariate analysis of variance showed standard deviations of head and trunk were similar within each task ($p > .05),$ but standard deviations of head and trunk in frequency, amplitude, and phase were significantly different from normal ($p < .05),$ suggesting frequency, amplitude, and phase were more challenging tasks than normal. Frequency analyses of head on trunk angular velocities revealed the use of two movement strategies used by subjects. The first was a compensatory strategy where head movements were equal and opposite to trunk movements. This was used at higher frequencies of trunk movement and at high and low frequencies during frequency, amplitude, and phase. The second was a non-compensatory strategy where head movements were not equal and opposite to trunk movements. This strategy was used primarily at low frequencies of trunk movement. In comparison to a seated rotation task where compensatory head on trunk motion was observed at frequencies of 2 Hz, subjects in this study demonstrated compensatory motion at 10 Hz during locomotor tasks. This suggests that during seated rotations trunk motion acts as a perturbation to head movement. Whereas during locomotor tasks head on trunk motion cooperates to produce head stability. Issue Date: 1996 Type: Text Language: English URI: http://hdl.handle.net/2142/22156 ISBN: 9780591087598 Rights Information: Copyright 1996 Cromwell, Ronita Lee Date Available in IDEALS: 2011-05-07 Identifier in Online Catalog: AAI9702491 OCLC Identifier: (UMI)AAI9702491
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