The objective of this study is to investigate psychometric properties of dual-task walking assessments and compare effects of simultaneous or sequential combination of physical and cognitive training on dual-task walking and cognitive performance for community-dwelling healthy older adults.

English Synopsis

I. Title of Study:

Effects of simultaneous or sequential combination of physical and cognitive training on dual-task walking performance for community-dwelling healthy older adults: a randomized controlled trial.

II. Study Objectives:

The objective of this study is to investigate psychometric properties of dual-task walking assessments and compare effects of simultaneous or sequential combination of physical and cognitive training on dual-task walking and cognitive performance for community-dwelling healthy older adults. Specifically, the study aims to test: 1) the psychometric properties (i.e., test-retest reliability and validity) of dual-task walking outcome measures, 2) the effectiveness of delivering physical and cognitive training via simultaneous or sequential way (physical training concurrent to or followed by a cognitive training) on improving dual-task walking for healthy older adults by using good psychometric properties of outcome measures, 3) the changed CMI pattern of older adults after simultaneous or sequential physical and cognitive training.

III. Study Design A metric analysis and comparative efficacy research will be conducted at medical center(s). Sixty community-dwelling ambulatory healthy older adults will receive dual-task walking assessments twice at pretreatment with a 1-week interval for test-retest assessment and investigation of the reliability and validity of outcome measures. The primary outcome measure of the six dual-task walking assessments will include two types of walking conditions (walking at preferred speed and fast speed) and simultaneously perform three cognitive tasks (Serial Three Subtractions, Stroop, and Auditory Stroop tasks). These three cognitive tasks represent different domains of cognitive function: working memory and executive function. Concurrent validity will be studied to validate the dual-task walking measures with each other and with the item 14 of the mini-Balance Evaluation Systems test (Mini-BESTest) and dual-task Timed-up-and-Go test (dual-TUG) obtain concurrently for assessing dual-task ability. In addition, we will compare dual-task walking performance between older fallers and non-fallers to examine discriminant validity of dual-task assessments.

A comparative efficacy research is a single-blind, randomized controlled trial. Sixty healthy elderly will be randomized to physical training concurrent with cognitive training (P+C, n=20), or physical training followed by cognitive training (P-then-C, n=20), or physical training without cognitive training (P, n=20) groups. The P+C group will undertake standing balance, stepping, and treadmill walking training while concurrently perform cognitive tasks. The P-then-C group will train the same set of standing balance, stepping, and treadmill walking activities as the P+C group while followed by cognitive training later. The P group will only train the same set of standing balance, stepping, and treadmill walking activities as the other two groups. All three groups will receive training at progressively increasing task difficulty 3 times a week for 12 weeks and followed by another 12 weeks without exercise (follow-up). Two baselines, 12 week, and 24 week data will be analyzed using multivariate statistical analyses and groups will be compared on treatment related changes in dual-task walking and cognitive performance among participants. To determine comparative effectiveness of interventions on primary outcomes (dual-task walking speed and composite score of cognitive tasks), two way mixed repeated measure ANOVAs will be used.

A blinded assessor will administer four assessments. All participants will be examined gait and cognitive performance under single-task (walking only, cognitive tasks only) and dual-task conditions (walking while performing 3 cognitive tasks) at two baselines, post intervention, and 3-month follow-up. The primary outcome measure of gait and cognition is gait speed and composite score of accuracy and reaction time of the cognitive tasks under single- and dual-task conditions. The secondary outcome measures will be the Berg Balance Scale, Mini-BESTest, dual-TUG, Functional Gait Assessment, Physical Activity Scale for the Elderly, Activities-Specific Balance Confidence Scale, Chair Stand Test, hand-held dynamometers, and Geriatric Depression Scale Short Form. Repeated measure ANOVA will be used to compare measurements at baseline, after training, and follow-up among the groups.

Number of Planned Patients: 60 healthy older adults Duration of the Study: 2018/08/01～2021/07/31

Inclusion Criteria:

• age more than 65 years old
• able to walk 10 m;
• no severe vision, hearing, cognition, and language problems.

Exclusion Criteria:

• neurological or musculoskeletal diagnosis that affects walking
• unable standing for at least 2 minutes,
• MMSE score <24 or severe uncorrected visual deficits
• moderate to severe high blood pressure (systolic pressure ≧ 160mmHg and diastolic blood pressure ≧ 100mmHg )