Résumé :
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Dystrophin-deficient dogs (GRMD, LRMD) exhibit similar pathophysiological and clinical features as Duchenne patients and represent therefore the best animal model to evaluate a therapeutic benefit. Emerging systemic approaches and the associate necessity to assess their clinical efficiency have led us to develop a quantitative, discriminating and non-invasive method to analyse locomotion. Accelerometry, a gait analysis technique based on 3D recording of accelerations, seems to be easy to perform in dogs and a source of several quantified parameters. In order to test this method, 11 dystrophin-deficient and 5 healthy adult dogs were encouraged to walk or trot along a 20 metres corridor, as spontaneously as possible. Three axial accelerations were recorded close to the center of gravity, the accelerometer being placed under the sternum, using a light elastic belt tightened around the thorax (Equimetrix device ®). Recorded data were then analysed using specific gait analysis software on ten seconds-samples of steady state locomotion. The accelerometer device was well tolerated by the dogs. The trot was spontaneously adopted by healthy, and by less affected dystrophic dogs, whereas gait of severely affected animals was restricted to walk. The mean regularity of dorso-ventral accelerations was found to be significantly higher in healthy than in trotting dystrophic dogs. Total mechanical power of gait (W/kg) was also observed to be significantly decreased in dystrophic dogs. Interestingly, the medio-lateral component of the power was significantly increased in dystrophic dogs, demonstrating a swaying component in the gait of these dogs. These preliminary results show that accelerometry is a simple and non-invasive method of functional evaluation of dog’s gait and is efficient to quantitatively discriminate dystrophic from healthy dogs, using specific signal processing methods. Longitudinal studies are ongoing in order to describe gait evolutions of healthy versus dystrophic dogs at various ages, with various phenotypes and after treatment.
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