Impaired coordination of movements, in which a person cannot maintain an upright position of the body or stand without support, despite preserved muscle strength and the absence of paralysis. This condition is seen in various neurological diseases affecting balance and postural control, such as cerebellar ataxia, vestibular disorders, or functional (psychogenic) movement disorders. Patients may stagger, fall, or be unstable when trying to stand, although leg movements remain normal when sitting or lying down.