Assessment of balance control mechanisms in patient populations using perturbation-based modeling: a narrative review with clinical implications

Clinical assessments of balance often rely on indirect measures that offer limited insights into the underlying sensorimotor control mechanisms. Consequently, there is a need for standardized and objective quantification of balance control mechanisms. Research over the past 20 years has demonstrated that Central Sensorimotor Integration (CSMI)-type tests can reliably identify functionally relevant parameters accounting for experimentally observed dynamics of the balance control system. However, the complexity and the lack of standardization of this approach have led to heterogeneous methodologies and results, limiting the clinical adoption of CSMI-type testing. Thus, the objective of this narrative review is to explore the application of CSMI-type tasks in quantifying balance control across various clinical populations. We identified articles in PubMed and IEEE Xplore that utilized CSMI or similar methods, specifically those utilizing continuous, wide-bandwidth, pseudorandom surface or visual stimuli and those using linear feedback models of ankle joint control. A total of 18 articles were identified, covering older adults, and individuals with attention deficit hyperactivity disorder, cataracts, heredity spastic paraplegia, lumbar spinal stenosis, mild traumatic brain injury, Parkinson's disease, peripheral neuropathies, and vestibular losses. We outline considerations for interpreting results across studies and recommend steps for standardizing CSMI-type testing to facilitate its implementation in clinical settings, aiming to better understand mechanistic deficits in balance control and to target rehabilitation.