Abstract
BackgroundFatigue and ageing contribute to impaired control of walking and are linked to falls. In this project, fatigue was induced by maximum speed walking to examine fatigue effects on lower limb trajectory control and associated tripping risk and overall gait functions of older adults.MethodsEleven young (18–35 years) and eleven older adults (>65 years) conducted 5-minute preferred speed treadmill walking prior to and following 6-minute maximum fast walking. Spatio-temporal gait parameters and minimum foot clearance (MFC) were obtained. Maximal muscle strength (hamstrings and quadriceps) was measured on an isokinetic dynamometer. Heart rate (HR) and rating of perceived exertion (RPE) assessed physiological effort and subjective fatigue. Physiological Cost Index computed walking efficiency.ResultsFatigue due to fast walking increased step length, double support time and variability of step width. Only older adults reduced MFC due to fatigue. A trend of longer double support with greater MFC was found in the non-dominant limb. Lower walking efficiency was characterised as the ageing effect. Older adults did not increase HR during fast walking but higher RPE scores were observed.ConclusionsOlder adults can increase tripping risk by 6 minutes of fast walking possibly by both impaired walking efficiency based on cardiac capacity and higher perceived fatigue due to elevated caution level. Regardless of age, increased step width variability due to fatigue was observed, a sign of impaired balance. Longer double support and greater MFC observed in the older adults’ non-dominant limb could be an asymmetrical gait adaptation for safety.Electronic supplementary materialThe online version of this article (doi:10.1186/1743-0003-11-155) contains supplementary material, which is available to authorized users.
Highlights
Fatigue and ageing contribute to impaired control of walking and are linked to falls
It was expected that treadmill walking would be fatiguing for older adults but the present findings suggest that self-selected fast walking on a treadmill does not allow maximal physical effort due to caution
Declines in walking efficiency based on cardiac capacity and higher perceived exertion were identified in the older individuals, suggesting age-associated proneness to fatigue
Summary
Fatigue and ageing contribute to impaired control of walking and are linked to falls. In this project, fatigue was induced by maximum speed walking to examine fatigue effects on lower limb trajectory control and associated tripping risk and overall gait functions of older adults. Most falls in older adults occur during dynamic activity, such as walking [4] and the risk factors for falling are typically due to mismatched interactions between environmental demands and intrinsic factors associated with ageing [5]. In the everyday environment walking biomechanics are expected to be influenced by fatigue, which may be further accentuated with ageing, such that older adults show a disproportionate decline in gait control and an increased falls risk when fatigued
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
