Modeling spasticity: a systematic review

Spasticity, a type of hypertonia characterized by a velocity-dependent increase in muscle tone, is associated with damage to the brain and/or spinal cord in different neurological conditions. However, secondary non-neurological factors, such as soft tissue changes, can complicate the assessment and differentiation of the underlying causes. Accurate assessment is crucial for effective treatment planning, with clinicians relying on passive movement to grade the 'feel' of the spastic limb. This review aims to identify and evaluate the feasibility of spasticity models or simulations for clinical teaching. Models based on human spastic limbs were examined, with no restrictions on specific conditions or populations. A comprehensive search of four databases and gray literature was conducted to identify relevant studies. Criteria for inclusion focused on model development, data, and evaluation processes. Study selection and data extraction were carried out by independent reviewers, and data synthesis was performed by systematically mapping model properties, methods, and utility. The quality of the studies was assessed using an adapted framework for health technology assessments. The findings highlight opportunities for the development of simulation models to support training. However, significant limitations to the existing evidence base limit the feasibility of developing spasticity models based on existing literature.