Valid and reliable instruments for the clinical assessment of the effect of ankle-foot orthoses on balance

Balance, a complex integration of the somatosensory, visual, and vestibular systems, has a substantial impact on functional ability in persons with locomotor disorders or sports-related injury. Ankle-foot orthoses (AFOs), by virtue of their observable impacts on the somatosensory system, are likely to influence balance. To investigate the effect of AFOs on balance, valid, reliable, and clinically justifiable balance measures need to be identified and used. The purpose of this article is to review the psychometric properties of those outcome measures with established clinical utility in the assessment of balance and to identify the potential balance measures for use in orthotic management, both clinically and in future research. This review includes the testing procedures and psychometric data for the following outcome measures: Berg Balance Scale, Pediatric Balance Scale, Activity-Specific Balance Confidence Scale, Timed Up and Go Test, Functional Reach Test, Single-Leg Stance Test, Star Excursion Balance Test, and Balance Error Scoring System. Assessments are discussed related to the target subjects: adult with locomotor disorder, pediatric with locomotor disorder, or athlete. All measures in this review were found to have at least acceptable psychometric properties. Of all the measures reviewed within the locomotor dysfunction category, the Timed Up and Go Test seems to have the most sound psychometric properties as a measure of dynamic balance and seems to be the most sensitive balance measure used thus far in research investigating the effects of AFOs on balance. Of the recommended measures of balance for the athletes, both the Star Excursion Balance Test and the Balance Error Scoring System have similar psychometric pros and cons and limited use in orthotics research. Utilization of more than one measure is suggested, so that assessment can be made of more than one health-related domain.