Gait variability is related to functional decline in the elderly. The dual-task Timed Up and Go Test (TUG-DT) reflects the performance in daily activities. Objective: To evaluate the differences in time to perform the TUG with and without DT in elderly women with different ages and levels of education and physical activity. Method: Ninety-two elderly women perfomed the TUG at usual and fast speeds, with and without motor and cognitive DT. Results: Increases in the time to perform the TUG-DT were observed at older ages and lower educational levels, but not at different levels of physical activity. More educated women performed the test faster with and without DT at both speeds. When age was considered, significant differences were found only for the TUG-DT at both speeds. Conclusion: Younger women with higher education levels demonstrated better performances on the TUG-DT.Keywords: elderly, gait, Timed Up and Go, dual task. RESUMOAlterações da marcha são indícios de declínio funcional em idosos. O TUG com dupla tarefa (TUG-DT) reflete o desempenho das atividades do cotidiano. Objetivo: Avaliar as diferenças no tempo de execução do TUG com e sem DT em idosas com diferentes faixas etárias, e níveis de escolaridade e atividade física. Método: Noventa e duas idosas foram avaliadas pelo TUG nas velocidades usual e máxima, sem e com DT cognitiva e motora. Resultados: Houve aumento no tempo de execução do TUG-DT em idosas com maior faixa etária e menor escolaridade, mas não para diferentes níveis de atividade física. Aquelas com maior escolaridade realizaram o teste mais rápido com e sem DT nas duas velocidades. Com relação à faixa etária, foram obervadas diferenças apenas nos testes com DT nas duas velocidades. Conclusão: Idosas mais jovens com maior escolaridade demonstraram um melhor desempenho no TUG com DT.Palavras-chave: idosos, marcha, teste Timed Up and Go, dupla tarefa.The aging rate has been growing rapidly worldwide in the last decades, and this has exerted strong influences on the dynamics of the society development 1 , with increases in chronic and degenerative diseases, higher dependency indices, and high rates of institutionalization and hospitalization 1 . Functional capacity (FC) refers to the competence of the individuals to preserve their physical and mental abilities necessary for an independent life. FC is an important marker of healthy, independent, and successful aging and has a positive impact on quality of life, especially regarding motor abilities 2 . Changes in gait patterns and speeds are related to difficulties in performing everyday activities, and indicate functional declines and hospitalization in individuals above 75 years of age 3,4 . Several studies have shown increased activation and inter-relations of brain structures related to cognition and

Clinical gait analysis is widely used in clinical routine to assess the function of patients with motor disorders. The proper assessment of the patient's function relies greatly on the repeatability between the measurements. Marker misplacement has been reported as the largest source of variability between measurements and its impact on kinematics is not fully understood. Thus, the purpose of this study was: 1) to evaluate the impact of the misplacement of the lateral femoral epicondyle marker on lower limb kinematics, and 2) evaluate if such impact can be predicted. The kinematic data of 10 children with cerebral palsy and 10 aged-match typical developing children were included. The lateral femoral epicondyle marker was virtually misplaced around its measured position at different magnitudes and directions. The outcome to represent the impact of each marker misplacement on the lower limb was the root mean square deviations between the resultant kinematics from each simulated misplacement and the originally calculated kinematics. Correlation and regression equations were estimated between the root mean square deviation and the magnitude of the misplacement expressed in percentage of leg length. Results indicated that the lowerlimb kinematics is highly sensitive to the lateral femoral epicondyle marker misplacement in the anterior-posterior direction. The joint angles most impacted by the anterior-posterior misplacement were the hip internal-external rotation (5.3˚per 10 mm), the ankle internalexternal rotation (4.4˚per 10 mm) and the knee flexion-extension (4.2˚per 10 mm). Finally, it was observed that the lower the leg length, the higher the impact of misplacement on kinematics. This impact was predicted by regression equations using the magnitude of misplacement expressed in percentage of leg length. An error below 5˚on all joints requires a marker placement repeatability under 1.2% of the leg length. In conclusion, the placement of the lateral femoral epicondyle marker in the antero-posterior direction plays a crucial role on the reliability of gait measurements with the Conventional Gait Model.

Introduction: The physiological deterioration associated with ageing exposes elderly persons to greater risks of falls, especially during the performance of simultaneous tasks during gait. Objectives: To evaluate the effects of dual tasks (DT) on spatiotemporal gait parameters and to identify the tools and tasks most commonly used to assess the performance of DT among the elderly. Method: Searches of the MEDLINE, PsycINFO, CINAHL, and SciELO databases were conducted. Observational studies, which evaluated gait changes during the performance of DT, published up to April 2014, were selected. Results: A total of 385 articles were found, of which 28 were selected. Decreases in speed and increases in stride variability, stride time, step width, and double support time were observed under DT conditions. Motion analysis systems, such as the GAITRite walkway® system were the mostly commonly used instruments for the analyses of kinematic parameters (16 studies). DT was most commonly assessed by arithmetic calculations in 20 studies, followed by verbal fluency, in nine studies. The gait parameters most commonly assessed were speed (19 studies), followed by stride variability (14 studies). Conclusion: The elderly showed changes in spatiotemporal gait parameters under DT conditions. Gait speed and stride variability were often assessed and, together, were considered good indicators of risks of falls.

Clinical gait analysis supports treatment decisions for patients with motor disorders. Measurement reproducibility is affected by extrinsic errors such as marker misplacement—considered the main factor in gait analysis variability. However, how marker placement affects output kinematics is not completely understood. The present study aimed to evaluate the Conventional Gait Model’s sensitivity to marker placement. Using a dataset of kinematics for 20 children, eight lower-limb markers were virtually displaced by 10 mm in all four planes, and all the displacement combinations were recalculated. Root-mean-square deviation angles were calculated for each simulation with respect to the original kinematics. The marker movements with the greatest impact were for the femoral and tibial wands together with the lateral femoral epicondyle marker when displaced in the anterior–posterior axis. When displaced alone, the femoral wand was responsible for a deviation of 7.3° (± 1.8°) in hip rotation. Transversal plane measurements were affected most, with around 40% of simulations resulting in an effect greater than the acceptable limit of 5°. This study also provided insight into which markers need to be placed very carefully to obtain more reliable gait data.