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The Hypertonia Assessment Tool (HAT) is a research and clinical guide for identifying the different types of hypertonia in the paediatric population. It helps both researchers and clinicians to identify when spasticity or dystonia are present. The HAT is used in research settings to better describe the subjects’ hypertonia sub-type. For clinicians, it helps to identify when spasticity, dystonia or mixed tonal patterns are present which can help to guide treatment and/or diagnostic decisions.

Developed by Dr. Darcy Fehlings, her team in the Cerebral Palsy Discovery Lab in the Bloorview Research Institute, and in conjunction with Dr. Jon Mink, Dr. Anne Kawamura and the Childhood Motor Task Group, the HAT is a seven-item tool that has been developed for children and youth between the ages of four to 19 years.