TY - JOUR A1 - Beijersbergen, Chantal M. I. A1 - Hortobagyi, Tibor A1 - Beurskens, Rainer A1 - Lenzen-Grossimlinghaus, Romana A1 - Gabler, Martijn A1 - Granacher, Urs T1 - Effects of Power Training on Mobility and Gait Biomechanics in Old Adults with Moderate Mobility Disability: Protocol and Design of the Potsdam Gait Study (POGS) JF - Gerontology N2 - Background: Walking speed decreases in old age. Even though old adults regularly participate in exercise interventions, we do not know how the intervention-induced changes in physical abilities produce faster walking. The Potsdam Gait Study (POGS) will examine the effects of 10 weeks of power training and detraining on leg muscle power and, for the first time, on complete gait biomechanics, including joint kinematics, kinetics, and muscle activation in old adults with moderate mobility disability. Methods/Design: POGS is a randomized controlled trial with two arms, each crossed over, without blinding. Arm 1 starts with a 10-week control period to assess the reliability of the tests and is then crossed over to complete 25-30 training sessions over 10 weeks. Arm 2 completes 25-30 exercise sessions over 10 weeks, followed by a 10-week follow-up (detraining) period. The exercise program is designed to improve lower extremity muscle power. Main outcome measures are: muscle power, gait speed, and gait biomechanics measured at baseline and after 10 weeks of training and 10 weeks of detraining. Discussion: It is expected that power training will increase leg muscle power measured by the weight lifted and by dynamometry, and these increased abilities become expressed in joint powers measured during gait. Such favorably modified powers will underlie the increase in step length, leading ultimately to a faster walking speed. POGS will increase our basic understanding of the biomechanical mechanisms of how power training improves gait speed in old adults with moderate levels of mobility disabilities. (C) 2016 S. Karger AG, Basel KW - Aging KW - Walking speed KW - Exercise KW - Muscle power KW - Gait kinematics KW - Gait kinetics Y1 - 2016 U6 - https://doi.org/10.1159/000444752 SN - 0304-324X SN - 1423-0003 VL - 62 SP - 597 EP - 603 PB - Karger CY - Basel ER - TY - JOUR A1 - Beurskens, Rainer A1 - Helmich, Ingo A1 - Rein, Robert A1 - Bock, Otmar L. T1 - Age-related changes in prefrontal activity during walking in dual-task situations: A fNIRS study JF - International journal of psychophysiology N2 - Background: Previous studies suggest that the human gait is under control of higher-order cognitive processes, located in the frontal lobes, such that an age-related degradation of cognitive capabilities has a negative impact on gait. Results: Our behavioral data partly confirm previous accounts on higher dual-task costs in stepping parameters (i.e., decreased step duration) in old age, particularly with a visual task and negative dual-task cost (i.e., improved performance) during the verbal task in young adults. Functional imaging data revealed little change of prefrontal activation from single- to dual-task walking in young individuals. In the elderly, however, prefrontal activation substantially decreased during dual-task walking with a complex visual task. Conclusion: We interpret these findings as evidence for a shift of processing resources from the prefrontal cortex to other brain regions when seniors face the challenge of walking and concurrently executing a visually demanding task. (C) 2014 Elsevier B.V. All rights reserved. KW - fNIRS KW - Aging KW - Locomotion KW - Neural activation KW - Executive function KW - Dual-task walking Y1 - 2014 U6 - https://doi.org/10.1016/j.ijpsycho.2014.03.005 SN - 0167-8760 SN - 1872-7697 VL - 92 IS - 3 SP - 122 EP - 128 PB - Elsevier CY - Amsterdam ER -