Development and validation of an innovative tool for the assessment of biomechanical strategies: The Timed “Up and Go” – Assessment of Biomechanical Strategies (TUG-ABS) for individuals with stroke

Abstract

To develop and validate a clinical tool based on the biomechanical strategies exhibited by people with hemiparesis due to stroke during the performance of the Timed "Up and Go" test. The Timed "Up and Go" Assessment of Biomechanical Strategies (TUG-ABS) was developed for subjects with stroke, based on the analyses of 3 sources of information: published evidence; opinions of rehabilitation professionals; and observations of TUG performances, followed by a multi-step approach, which involved the investigation of the reliability, content, and criterion-related validity of the preliminary version. Content validity was established by an expert panel, whereas intra- and inter-rater reliability was established by two independent examiners. Criterion-related validity was established by comparing the TUG-ABS scores at the item level obtained by independent analyses of video observations and the gold standard motion analysis system. The final tool included the items, which showed acceptable values for these psychometric properties. The preliminary version consisted of 24 items with 3 response categories. Twenty-one items showed acceptable content validity (0.72 ≤ κ ≤ 1.00; p ≤ 0.01), 19 acceptable intra- and inter-rater reliability (0.36 ≤ κ ≤1.00; p ≤ 0.04), and 15 acceptable criterion-related validity (0.29 ≤ κ ≤ 1.00; p ≤ 0.04). The final developed 15-item TUG-ABS version proved to be valid and reliable for individuals with hemiparesis due to stroke, but it should be clinically validated before being used for clinical applications and research purposes.