Active movement of the wrist and hand involves a complex interaction of intrinsic and extrinsic musculature. For people with neurologically-based impairment, an imbalance of muscle activity drives the pattern of wrist and hand deformity (Wilton, 2013). Even though impairment is unique to each individual, hand deformity tends to follow characteristic patterns (Wilton, 2003, 2013).

The Neurological Hand Deformity Classification (NHDC) is framed within the body functions and structure domain of the International Classification of Functioning Disability and Health (ICF) (World Health Organization, 2001). It is an impairment-based classification designed to categorise hand deformity. Classification is made according to observed wrist and hand movement. Differentiation between the categories is determined by wrist position and wrist and finger movement. The NHDC is designed for use with clients of any age across all neurologically-based upper limb impairments. The application of the NHDC is not limited to a specific diagnosis, but has been predominantly used by the authors in clinical practice with children and adults with cerebral palsy.