Details of Thesis

Title The Response of Elderly Female Fast Gait to Whole Body Vibration
Author Lorenzen, Hans Christian
Institution Australian Catholic University
Date 2007
Abstract Background: Older adults walk more slowly than healthy young adults at fast and normal walking speeds. These age-associated changes in mobility impact upon daily function. A slower gait, for example, may reduce the older adult’s ability to safely cross at traffic intersections due to the time restriction. Recent research has demonstrated whole body vibration (WBV) can improve the strength and power (Roelants, Delecluse & Verschueren, 2004; Russo et al., 2003; Verschueren, Roelants, Delecluse, Swinnen, Vanderschueren & Boonen, 2004) of community dwelling elderly females, and the mobility of nursing home residents (Bautmans, Van Hees, Lemper & Mets, 2005; Bruyere et al., 2005). To date, no published research has examined the impact WBV has on the gait parameters of community dwelling elderly females. The research was conducted in three phases. Phase One – Development of a WBV Platform: This phase outlines the development of a WBV platform (ACUWBV) that was designed and built for this research. A unique aspect of the ACUWBV was the method of adjusting WBV amplitude and therefore intensity. Current WBV technology, using tilting oscillations, requires the individual to increase their stance width. The ACUWBV allowed for the adjustment of WBV amplitude while maintaining the same stance width. The reliability and accuracy of the ACUWBV eccentric cam was measured during this phase of the research. Although an intraclass correlation coefficient of 0.4 was calculated and is considered an indication of low reliability, calculations of typical error (TE -95% error range) for each amplitude indicated the error to be small in the overall precision of the instrument. Specifically, at a frequency of 20 Hz, the expected WBV acceleration ranges for amplitudes of 0.5 mm and 1.0 mm were 7.58 m.s-2 to 8.85 m.s-2 (TE = 0.02 mm) and 16.90 m.s-2 to 17.53 m.s.-2 (TE = 0.01 mm), respectively. Phase Two – Pilot Study: This phase established the response of elderly community-dwelling female fast gait to WBV. Seven elderly female participants attended three WBV sessions per week for three weeks. Participants performed fast walks over an electronic walkway (GAITRite) at the end of each WBV session. A time-series graph displayed a linear increase in stride velocity over the three week intervention period. Conversely, stride time, stance time and double support time exhibited linear decreases. However, stride time (p=0.04) and stance time (p=0.04) were the only variables that exhibited a significant difference. It was concluded that the linear changes in stride velocity, stride time, stance time and double support time warranted further investigation with a larger sample size within a longer intervention period. Phase Three – Major Study: Phase three was an extension of phase two. This WBV intervention study was performed over a twelve week period. Twenty-two elderly female participants were placed in one of two groups. Group one (placebo/WBV; Group; n=12) was exposed to a placebo intervention for the first six weeks followed by a six week WBV intervention. Group two (Group WBV/placebo; n=10) was exposed to WBV for the first six weeks and a placebo intervention for the following six weeks. Group placebo/WBV exhibited no change in stride velocity during the placebo period, but a seven per cent increase during the six week WBV period (p=0.005). The changes in stride velocity coincided with increases in stride length (p=0.017), and reductions in stride time (p=0.007), stance time (p=0.001) and double support time (p=0.001). Group WBV/Placebo demonstrated stride velocity to increase by five per cent during the WBV period. Although the time-series graphs demonstrated improvements in stride velocity to be associated with decreases in stride time, stance time, and double support time, the changes failed to reach significance. Single support time and stride length showed no change over the WBV period. The improvements shown by group WBV/placebo from the first six weeks of WBV were maintained during the six week placebo (detraining) period. In summary, WBV was an effective intervention for enhancing the walking speed of community dwelling elderly female gait. This form of exercise may have positive outcomes on the daily function of elderly females, which in turn may improve their quality of life.
Thesis 01front.pdf  49KB
02whole.pdf 1,606KB

Top of Page