Base of support is not wider in chronic ataxic and unsteady patients.

"Wide-based gait" is considered indicative of imbalance. No quantitative gait analyses, however, have related base of support to steadiness during gait. To determine whether patients with cerebellar or vestibular disorders had a wider base of support than matched healthy individuals, we analyzed 102 balance-impaired patients and healthy subjects during free and paced gait. Kinematic data were collected using a high-precision optoelectronic system. There were no significant differences in the base of support between unsteady and healthy subjects, nor between patients with vestibular and cerebellar diagnoses. The base of support correlated with the body mass index and waist circumference in all subject groups. These data suggest that base of support during gait fails to identify balance-impaired subjects and is related more to biomechanical than to neurological factors. Therefore, "wide-based gait" should no longer be considered the sine qua non of ataxic or unsteady gait. Clinicians should not focus on decreasing base of support as a therapeutic goal for chronic, unsteady patients.