Lateral step up test (LSUT): reliability and associations with motor functions in people with chronic stroke

Abstract

BACKGROUND AND RATIONALE: Muscles weakness is common after stroke, and it could impede the performance of daily motor functions including standing up from sitting, walking on level ground, and walking up and down stairs. Thus, clinicians need a reliable, valid and easy-to-administer outcome measures in order to document the changes of muscle strength during the rehabilitation process. The Lateral Step Up Test (LSUT) is one of the clinical tests which can quantify the functional muscle strength of the lower extremity. A 10 cm step was used and placed at one side of the subject. Subjects were required to extend the tested leg on the step into full extension, and then return to flexion until the non-tested leg touches the floor. Number of counts completed in 15 seconds was recorded. The objectives of this study was to investigate the reliability of LSUT and its correlation with stroke-specific impairments. METHODS: This study was a cross-sectional clinical trial with 33 people with chronic stroke. LSUT counts was administered along with Fugl-Meyer motor assessment for the lower extremities (FMA-LE), muscle strength of affected leg, Five Times Sit to stand test (FTSTS), Berg Balance Scale (BBS), timed Up and Go test (TUG) and Activities-specific Balance Confidence (ABC) scores. The LSUT was conducted in 2 sessions with 5–7 days apart by 2 independent assessors. The order of testing on motor functions was randomized by drawing lots. RESULTS: Both paretic and non-paretic LSUT counts showed excellent intra-rater, inter-rater and test-restest reliabilities (intra intraclass correlation coefficients = 0.936–0.991) Significant correlations were found between both paretic and non-paretic LSUT counts and FMA-LE scores, muscle strength of knee extensors and flexors, FTSTS times, BBS scores, TUG times and ABC scores. CONCLUSION: LSUT is a reliable, valid and easy-to-administer clinical assessment for assessing the functional muscle strength in people with chronic stroke.