Comparison of energy cost of walking with and without a carbon composite ankle foot orthosis in stroke subjects

• 13th ISPO World Congress Poster [3009] Abstract [207] | Topic: Orthotics Author: Danielsson, Anna (Göteborg SE) Dr. University of Gothenburg, Institute of Neuroscience and Physiology - Clinical Neuroscience and Rehabilitation Title: Comparison of Energy Cost of Walking with and without a Carbon Composite Ankle Foot Orthosis in Stroke Subjects Coauthors: Sunnerhagen KS, Willén C Summary: Oxygen cost, gait speed and perceived exertion was measured in 10 subjects with stroke walking with and without a carbon composite ankle foot orthosis. Walking with ankle foot orthosis was statistically less energy demanding and the speed somewhat higher compared to unbraced walking. Introduction: The opinions on effects of AFOs on functional outcome after stroke are inconsistent and the clinical significance of changes reported has been questioned. The improved walking velocity with an AFO as compared to unbraced walking seen in some studies may involve a reduction in energy cost. To our knowledge, only two studies report reduced energy cost with the use of an AFO. The aim was to measure and compare the energy expenditure and walking speed with and without a carbon composite AFO in stroke subjects. Methods: Ten persons with prior stroke, habituated to a carbon composite AFO were included. First the self-selected speeds on a tredmill without (speed I) and with (speed II) the AFO were determined in randomised order. The energy expenditure and heart rate were estimated with a stationary, computerized system for breath-by-breath analysis. Two measurements of energy expenditure were carried out with and without the AFO in randomized order at speed I. A third measurement was made with the AFO at speed II. Each trial lasted for five minutes. The measurements were repeated in reversed order once within one week. The energy cost per minute was divided by walking speed for estimation of energy cost per distance. Data was analysed with Wilcoxons sign rank test. Results: The mean self-selected walking speed was 20% higher (p = 0.027) with the ankle foot orthosis than without. Walking at speed I with an AFO was 4% less energy demanding (VO2 mL•kg-1•min-1) (p=0.028) than walking without AFO at the same speed. The energy cost (VO2 mL•kg-1•m-1) at speed I was also significantly lower with the AFO (p = 0.037) than without. Heart rate or perceived exertion did not differ between the two conditions. There was no significant difference in energy expenditure (VO2 mL•kg-1•min-1) between walking at speed I without AFO and speed II with AFO. However, the energy cost (VO2 mL•kg-1•m-1), was 12% lower (p=0.024) with the AFO. Heart rate and perceived exertion showed no difference between the two conditions. Conclusion: A carbon composite ankle foot orthosis may decrease energy demands and increase walking speed after stroke. The differences in energy cost seen in this study were small and not clinically significant whereas an increase in walking speed might have some impact on walking capacity. Further studies on the effects of an AFO on walking ability after stroke are wanted. References: Franceschini M, Massucci M, Ferrari L, Agosti M, Paroli C. Effects of an ankle-foot orthosis on spatiotemporal parameters and energy cost of hemiparetic gait. Clin Rehabil 2003;17(4):368-72. Corcoran PJ, Jebsen RH, Brengelmann GL, Simons BC. Effects of plastic and metal leg braces on speed and energy cost of hemiparetic ambulation. Arch Phys Med Rehabil 1970;51(2):69-77. de Wit DC, Buurke JH, Nijlant JM, Ijzerman MJ, Hermens HJ. The effect of an ankle-foot orthosis on walking ability in chronic stroke patients: a randomized controlled trial. Clin Rehabil 2004;18(5):550-7 Leung J, Moseley A. Impact of ankle-foot orthoses on gait and leg muscle activity in adults with hemiplegia: systematic literature review. Physiotherapy 2003;89(1):39-55. Danielsson A, Sunnerhagen KS. Energy expenditure in stroke subjects walking with a carbon composite ankle foot orthosis. J Rehabil Med 2004;36:165-8.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Neurologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Neurology (hsv//eng)

Nyckelord

stroke

gait

orthosis

energy expenditure

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