Balance Control of Step Ascent: Effects of Movement Strategy and Diabetes

  • 李 怡亭

Student thesis: Master's Thesis


Background: Ascending to an elevated surface while walking is a common and challenging task for older adults Having a pause before ascending is a strategy often adopted by older adults and may reduce balance threat Diabetic patients often have problems with balance control especially those with neuropathy patients and subsequent sensorimotor impairments The purpose of this study was to investigate the influence of having a pause before ascending on balance control during and after ascending a step stool in healthy older adults older diabetic patients with and without neuropathy Methods: Twenty-three healthy older adults (CON) twenty-two older diabetic patients without neuropathy (DM-nonNP) and twenty-two older diabetic patients with neuropathy (DM-NP) participated in this study There were two task conditions In the walk-step condition (WS) subjects were instructed to walk and then directly step up onto a 9 cm (LOW) or 18 cm (HIGH) step stool which was placed 6 m from the starting position In the pause-step condition (PS) subjects were instructed to walk pause briefly in front of the stool to stabilize themselves and then step up onto the step stool For both conditions the subjects were instructed to stand quietly after stepping onto the step stool During ascending the motion was divided into four phases based on the motion of the leading limb including initial double-limb support (IDS) swing (SW) second double-limb support (SDS) and single-limb stance (SLS) An accelerometer was placed at the spinous process of the 3rd lumbar vertebrae to measure the acceleration of the body’s center of mass in the anteroposterior (AP) mediolateral (ML) and vertical (VT) directions The range root-mean-square (RMS) and standard deviation (SD) of the acceleration were analyzed using multivariate repeated measures analysis of variance Also the acceleration during the first one second after both feet making contact with the step stool was also analyzed Results: During ascending HIGH had significantly greater AP acceleration in the SW SDS and SLS phases greater ML acceleration in the SW and SLS phases and greater VT acceleration in the SDS and SLS phases compared to LOW Compared to WS PS had significantly smaller AP and VT acceleration in the first three phases and smaller ML acceleration in the first two phases regardless of the step height In LOW PS had significantly smaller ML acceleration than WS in CON and DM-nonNP subjects during the SDS phase whereas in HIGH all subjects had smaller ML acceleration than LOW During quiet standing after ascending HIGH had significantly greater AP acceleration than LOW during the first 0 75 seconds Compared to WS PS had significantly smaller ML acceleration during the first 0 25 s period for all subjects in LOW whereas in HIGH only CON and DM-nonNP had such a finding Conclusion: For older adults even those with different sensorimotor functions having a pause before ascending decreased imbalance during the ascending phase Thus having a pause before ascending could be recommended for older adults especially for challenging conditions
Date of Award2014 Dec 8
Original languageEnglish
SupervisorSang-I Lin (Supervisor)

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