title: A flexed posture in elderly patients is associated with impairments in postural control during walking.
abstract: A flexed posture (FP) is characterized by protrusion of the head and an increased thoracic kyphosis (TK), which may be caused by osteoporotic vertebral fractures (VFs). These impairments may affect motor function, and consequently increase the risk of falling and fractures. The aim of the current study was therefore to examine postural control during walking in elderly patients with FP, and to investigate the relationship with geriatric phenomena that may cause FP, such as increased TK, VFs, frailty, polypharmacy and cognitive impairments. Fifty-six elderly patients (aged 80 ± 5.2 years; 70% female) walked 160 m at self-selected speed while trunk accelerations were recorded. Walking speed, mean stride time and coefficient of variation (CV) of stride time were recorded. In addition, postural control during walking was quantified by time-dependent variability measures derived from the theory of stochastic dynamics, indicating smoothness, degree of predictability, and local stability of trunk acceleration patterns. Twenty-five patients (45%) had FP and demonstrated a more variable and less structured gait pattern, and a more irregular trunk acceleration pattern than patients with normal posture. FP was significantly associated with an increased TK, but not with other geriatric phenomena. An increased TK may bring the body's centre of mass forward, which requires correcting responses, and reduces the ability to respond on perturbation, which was reflected by higher variation in the gait pattern in FP-patients. Impairments in postural control during walking are a major risk factor for falling: the results indicate that patients with FP have impaired postural control during walking and might therefore be at increased risk of falling.
authors.affiliation: Department of Geriatric Medicine Slotervaart Hospital, Louwesweg 6, 1066 EC Amsterdam, The Netherlands. Electronic address: Maartje.deGroot@slz.nl.
authors.forename: Maartje H
authors.initials: MH
authors.lastname: de Groot
authors.affiliation: Department of Geriatric Medicine Slotervaart Hospital, Louwesweg 6, 1066 EC Amsterdam, The Netherlands; Department of Internal Medicine & Geriatric Medicine, Spaarne Hospital, Spaarneplein 1, 2134 TM Hoofddorp, The Netherlands.
authors.forename: Hanna C
authors.initials: HC
authors.lastname: van der Jagt-Willems
authors.affiliation: Department of Geriatric Medicine Slotervaart Hospital, Louwesweg 6, 1066 EC Amsterdam, The Netherlands.
authors.forename: Jos P C M
authors.initials: JP
authors.lastname: van Campen
authors.affiliation: Department of Rheumatology, VU Medical Centre, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands.
authors.forename: Willem F
authors.initials: WF
authors.lastname: Lems
authors.affiliation: Department of Pharmacy & Pharmacology, Slotervaart Hospital, Louwesweg 6, 1066 EC Amsterdam, The Netherlands; Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
authors.forename: Jos H
authors.initials: JH
authors.lastname: Beijnen
authors.affiliation: University of Groningen, University Medical Centre Groningen, Centre for Human Movement Sciences, Ant. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Claudine J C
authors.initials: CJ
authors.lastname: Lamoth
mesh_terms: D000058:Accidental Falls; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D007738:Kyphosis / Q000503:physiopathology*; D016014:Linear Models; D008159:Lumbar Vertebrae / Q000293:injuries / Q000503:physiopathology; D008297:Male; D010024:Osteoporosis / Q000503:physiopathology*; D004856:Postural Balance / Q000502:physiology; D011187:Posture / Q000502:physiology*; D018570:Risk Assessment; D016103:Spinal Fractures / Q000503:physiopathology*; D013904:Thoracic Vertebrae / Q000293:injuries / Q000503:physiopathology; D060726:Torso / Q000502:physiology; D016138:Walking / Q000502:physiology
keywords: Elderly; Flexed posture; Osteoporosis; Postural control; Walking