Reading disability or developmental dyslexia is a specific disorder of reading that is associated with inconsistent evidence of deficits in motor control. Balance measures have revealed the most convincing evidence and several dyslexia screening batteries include tests of postural stability. A prominent causal theory of dyslexia links reading and balance difficulties through mild impairment of the cerebellum. Cerebellar abnormalities are associated with other developmental disorders including Attention Deficit Hyperactivity Disorder (ADHD), which co-occurs with both dyslexia and motor deficits (Chapter 1). A meta-analysis of dyslexia and balance studies (Chapter 3) yielded a robust (d = .64) combined between-groups effect size, however heterogeneity was revealed across studies. The strongest predictor of postural stability was whether samples had been screened for ADHD. Inconsistencies in sampling, procedure and measurement across studies were also revealed. The thesis aimed to introduce an objective, quantitative approach to the study of balance in dyslexia using theory and techniques from postural and balance research (Chapters 2 & 4). Unselected samples of adults and children from the dyslexia and normal reading populations were assessed on psychometric, literacy and behavioural measures. Postural stability was measured using digital optical motion capture (Qualisys Systems), obtained during a perturbation of balance caused by the release of a suspended weight equivalent to 5% body mass. The paradigm replicated the hitherto most frequently used balance measure with adults (Chapters 5 & 6) and children (Chapters 7 & 8). The findings suggest that balance difficulties in the dyslexia and general populations are correlates of reading difficulties but are related through hyperactivity or combined inattention and hyperactivity ratings. Tests of postural stability are therefore more likely to be useful predictors of risk of more general developmental disorder than specifically of reading failure. Postural control is therefore placed within the wider context of co-occurring developmental disorders (Chapter 9).
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:426556 |
| Date | January 2006 |
| Creators | Rochelle, K. S. H. |
| Publisher | Aston University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://publications.aston.ac.uk/12266/ |
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