title: Relationship between muscle impairments, postural stability, and gait parameters assessed with lower-trunk accelerometry in myotonic dystrophy type 1.
abstract: This study evaluated gait using lower-trunk accelerometry and investigated relationships between gait abnormalities, postural instability, handgrip myotonia, and weakness in lower-limb and axial muscle groups commonly affected in myotonic dystrophy type 1 (DM1). Twenty-two patients (11 men, 11 women; age = 42 years (range: 26-51)) with DM1 and twenty healthy controls (9 men, 11 women; age = 44 years (range: 24-50)) participated in this study. Gait analysis using lower-trunk accelerometry was performed at self-selected walking pace. Postural stability was measured via center of pressure displacement analysis using a force platform during eyes-closed normal stance. Handgrip myotonia was quantified using force-relaxation curve modeling. Patients displayed lower walking speed, stride frequency, stride length, gait regularity, and gait symmetry. Strength of ankle plantar flexors, ankle dorsal flexors and neck flexors correlated with interstride regularity in the vertical direction (ρ = 0.57, ρ = 0.59, and ρ = 0.44, respectively; all P < 0.05). Knee extension strength correlated with gait symmetry in the anteroposterior direction (ρ = 0.45, P < 0.05). Center of pressure velocity was greater in patients and correlated with neck flexion and ankle plantar flexion weakness (ρ = -0.51 and ρ = -0.62, respectively; both P < 0.05), and with interstride regularity in the vertical direction (ρ = -0.58, P < 0.05). No correlation was found between handgrip myotonia and any other variable studied. Lower-trunk accelerometry allows the characterization of gait pattern abnormalities in patients with DM1. Further studies are required to determine the relevance of systematic gait analysis using lower-trunk accelerometry for patient follow-up and intervention planning.
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France. Electronic address: damien.bachasson@gmail.com.
authors.forename: Damien
authors.initials: D
authors.lastname: Bachasson
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Moraux
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Gwenn
authors.initials: G
authors.lastname: Ollivier
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Decostre
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Ledoux
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Teresa
authors.initials: T
authors.lastname: Gidaro
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Servais
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France; Centre de Référence de Pathologie Neuromusculaire Paris-Est, Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Anthony
authors.initials: A
authors.lastname: Behin
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France; Centre de Référence de Pathologie Neuromusculaire Paris-Est, Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Tanya
authors.initials: T
authors.lastname: Stojkovic
authors.affiliation: Université Laval, Québec, Canada; Centre Interdisciplinaire de Recherche en Réadaptation et Intégration Sociale, Québec, Canada.
authors.forename: Luc J
authors.initials: LJ
authors.lastname: Hébert
authors.affiliation: Université Laval, Québec, Canada.
authors.forename: Jack
authors.initials: J
authors.lastname: Puymirat
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France; Centre de Référence de Pathologie Neuromusculaire Paris-Est, Assistance Publique-Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Eymard
authors.affiliation: Department of Pathology, Henri Mondor University Hospital, Créteil, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bassez
authors.affiliation: Institute of Myology, Pitié-Salpêtrière Hospital, Paris, France.
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Hogrel
mesh_terms: D061725:Accelerometry; D000328:Adult; D001696:Biomechanical Phenomena; D015992:Body Mass Index; D005260:Female; D005684:Gait / Q000502:physiology; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000503:physiopathology*; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009223:Myotonic Dystrophy / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology; D000070857:Walk Test; D055815:Young Adult
keywords: Accelerometry; Balance; Gait; Muscle weakness; Myotonia; Myotonic dystrophy