title: Locomotor patterns in cerebellar ataxia.
abstract: Several studies have demonstrated how cerebellar ataxia (CA) affects gait, resulting in deficits in multijoint coordination and stability. Nevertheless, how lesions of cerebellum influence the locomotor muscle pattern generation is still unclear. To better understand the effects of CA on locomotor output, here we investigated the idiosyncratic features of the spatiotemporal structure of leg muscle activity and impairments in the biomechanics of CA gait. To this end, we recorded the electromyographic (EMG) activity of 12 unilateral lower limb muscles and analyzed kinematic and kinetic parameters of 19 ataxic patients and 20 age-matched healthy subjects during overground walking. Neuromuscular control of gait in CA was characterized by a considerable widening of EMG bursts and significant temporal shifts in the center of activity due to overall enhanced muscle activation between late swing and mid-stance. Patients also demonstrated significant changes in the intersegmental coordination, an abnormal transient in the vertical ground reaction force and instability of limb loading at heel strike. The observed abnormalities in EMG patterns and foot loading correlated with the severity of pathology [International Cooperative Ataxia Rating Scale (ICARS), a clinical ataxia scale] and the changes in the biomechanical output. The findings provide new insights into the physiological role of cerebellum in optimizing the duration of muscle activity bursts and the control of appropriate foot loading during locomotion.
authors.affiliation: Centre of Space Bio-Medicine, University of Rome Tor Vergata, Rome, Italy; Laboratory of Neuromotor Physiology, Istituto Di Ricovero e Cura a Carattere Scientifico Santa Lucia Foundation, Rome, Italy; g.martino@hsantalucia.it.
authors.forename: G
authors.initials: G
authors.lastname: Martino
authors.affiliation: Laboratory of Neuromotor Physiology, Istituto Di Ricovero e Cura a Carattere Scientifico Santa Lucia Foundation, Rome, Italy;
authors.forename: Y P
authors.initials: YP
authors.lastname: Ivanenko
authors.affiliation: Rehabilitation Centre Policlinico Italia, Rome, Italy; Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy;
authors.forename: M
authors.initials: M
authors.lastname: Serrao
authors.affiliation: Italian Workers' Compensation Authority, Department of Occupational Medicine, Monte Porzio Catone, Rome, Italy; and.
authors.forename: A
authors.initials: A
authors.lastname: Ranavolo
authors.affiliation: Laboratory of Neuromotor Physiology, Istituto Di Ricovero e Cura a Carattere Scientifico Santa Lucia Foundation, Rome, Italy;
authors.forename: A
authors.initials: A
authors.lastname: d'Avella
authors.affiliation: Italian Workers' Compensation Authority, Department of Occupational Medicine, Monte Porzio Catone, Rome, Italy; and.
authors.forename: F
authors.initials: F
authors.lastname: Draicchio
authors.affiliation: Rehabilitation Centre Policlinico Italia, Rome, Italy;
authors.forename: C
authors.initials: C
authors.lastname: Conte
authors.affiliation: Department of Medical and Surgical Sciences and Biotechnologies, Sapienza University of Rome, Latina, Italy;
authors.forename: C
authors.initials: C
authors.lastname: Casali
authors.affiliation: Centre of Space Bio-Medicine, University of Rome Tor Vergata, Rome, Italy; Laboratory of Neuromotor Physiology, Istituto Di Ricovero e Cura a Carattere Scientifico Santa Lucia Foundation, Rome, Italy; Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Lacquaniti
mesh_terms: D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D002524:Cerebellar Ataxia / Q000503:physiopathology*; D019054:Evoked Potentials, Motor; D005260:Female; D005684:Gait; D006801:Humans; D008124:Locomotion; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology
keywords: central pattern generator; cerebellar ataxia; gait adaptation; limb loading; muscle activation patterns