title: Relationship between gait initiation and disability in individuals affected by multiple sclerosis.
abstract: This study analyzes how multiple sclerosis (MS) does affect one of the most common voluntary activities in life: the gait initiation (GI). The main aim of the work is to characterize the execution of this task by measuring and comparing relevant parameters based on center of pressure (COP) patterns and to study the relationship between these and the level of expanded disability status scale (EDSS). To this aim, 95 MS subjects with an average EDSS score of 2.4 and 35 healthy subjects were tested using a force platform during the transition from standing posture to gait. COP time-series were acquired and processed to extract a number of parameters related to the trajectory followed by the COP. The statistical analysis revealed that only a few measurements were statistically different between the two groups and only these were subsequently correlated with EDSS score. The correlation analysis underlined that a progressive alteration of the task execution can be directly related with the increase of EDSS score. These finding suggest that most of the impairment found in people with MS comes from the first part of the COP pattern, the anticipatory postural adjustments (APAs). The central nervous system performs APAs before every voluntary movement to minimize balance perturbation due to the movement itself. Gait Initiation's APAs consist in some ankle muscles contractions that induce a backward COP shift to the swing limb. The analysis here performed highlighted that MS affected patients have a reduced posterior COP shift that reveals that the anticipatory mechanism is impaired.
authors.affiliation: Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy; Gait Analysis Lab, IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Galli
authors.affiliation: Multiple Sclerosis Center, Department of Public Health, Clinical and Molecular Medicine, University of Cagliari, Cagliari, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Coghe
authors.affiliation: Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Sanna
authors.affiliation: Multiple Sclerosis Center, Department of Public Health, Clinical and Molecular Medicine, University of Cagliari, Cagliari, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Cocco
authors.affiliation: Multiple Sclerosis Center, Department of Public Health, Clinical and Molecular Medicine, University of Cagliari, Cagliari, Italy.
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Marrosu
authors.affiliation: Department of Mechanical, Chemical and Materials Engineering,University of Cagliari, Piazza d'Armi, 09123 Cagliari, Italy. Electronic address: massimiliano.pau@dimcm.unica.it.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Pau
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D004185:Disability Evaluation; D005260:Female; D005528:Foot / Q000503:physiopathology; D005684:Gait / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology; D011187:Posture; D013997:Time Factors; D055815:Young Adult
keywords: Balance; Gait; Gait initiation; Multiple sclerosis