The effect of lower limb fatigue on obstacle clearance during steady state walking
M.Shiels, A.Kerr
Division of Physiotherapy, School of Health & Social Care, Glasgow Caledonian University, Cowcaddens Road, Glasgow, G4 0BA.
PURPOSE: To determine the effect of lower limb fatigue on obstacle clearance during steady state walking. RELEVANCE: Lower limb fatigue may have a negative effect on the ability to clear an obstacle when walking and thus may have implications for falls prevention programmes. SUBJECTS: Six healthy male and six healthy female subjects participated (mean age 24.2 + 1.5). METHODS: Subjects completed two sessions, the order of which was randomised. One involved a sub-maximal treadmill test to 80% age predicted maximum heart rate following the modified Bruce protocol proceeded by obstacle clearance and another session of obstacle clearance only. A 3-D motion analysis system (Qualisys Pro-reflex) allowed measurement of vertical toe height during gait by placing reflective markers on the medial and lateral malleoli and the base of the 1st and 5th metatarsal. Heart rate and rate of perceived exertion were measured before, during and at the end of the test, as indicators of fatigue. ANALYSIS: A paired t-test was carried out in order to compare obstacle clearance under normal conditions and after the lower limb had been fatigued. RESULTS: No significant difference (p = 0.329) in toe height was found between the normal and fatigued condition, indicating that lower limb fatigue had no effect on obstacle clearance during gait. CONCLUSION: Lower limb fatigue has no effect on obstacle clearance during steady state walking. However due to the small, healthy sample population there is a risk of a type II error and the relationship between fatigue and obstacle clearance remains unclear.
References
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