title: Normative data for arm swing asymmetry: how (a)symmetrical are we?
abstract: Arm swing asymmetry during gait may be a sensitive sign for early Parkinson's disease. There is only very limited information about how much asymmetry can be considered to be physiological. To assess the normal range of arm swing asymmetry, we investigated 60 healthy subjects. The influence of age, gender, and additional mental tasks (dual-tasking) on arm swing asymmetry was assessed. Limb kinematics of 60 healthy persons in three age groups (between 40 and 75 years) were measured with an ultrasound motion capture system while subjects walked on a treadmill. Treadmill velocity was varied (3 steps) and mental loads (2 different tasks) were applied in different trials. Additionally, a group of 7 patients with early Parkinson's disease was investigated. Arm swing amplitude as well as arm swing asymmetry varied considerably in the healthy subjects. Elderly subjects swung their arms more than younger participants. Only the more demanding mental load caused a significant asymmetry, i.e., arm swing was reduced on the right side. In the patient group, asymmetry was considerably higher and even more enhanced by mental loads. Our data indicate that an asymmetry index above 50 (i.e., one side has twice the amplitude of the other) may be considered abnormal. Evaluation of arm swing asymmetry may be used as part of a test battery for early Parkinson's disease. Such testing may become even more important when disease-modifying drugs become available for Parkinson's disease.
authors.affiliation: Department of Neurology, Ludwig-Maximilians-University Munich, Marchioninistr. 15, 81377 Munich, Germany. Electronic address: Annika.Plate@med.uni-muenchen.de.
authors.forename: A
authors.initials: A
authors.lastname: Plate
authors.affiliation: Department of Neurology, Ludwig-Maximilians-University Munich, Marchioninistr. 15, 81377 Munich, Germany. Electronic address: dani_s_@gmx.net.
authors.forename: D
authors.initials: D
authors.lastname: Sedunko
authors.affiliation: Department of Orthopedics, Physical Medicine and Rehabilitation, Ludwig-Maximilians-University Munich Marchioninistr. 15, 81377 Munich, Germany. Electronic address: Olena.Pelykh@med.uni-muenchen.de.
authors.forename: O
authors.initials: O
authors.lastname: Pelykh
authors.affiliation: Department of Orthopedics, Physical Medicine and Rehabilitation, Ludwig-Maximilians-University Munich Marchioninistr. 15, 81377 Munich, Germany. Electronic address: Cornelia.Schlick@med.uni-muenchen.de.
authors.forename: C
authors.initials: C
authors.lastname: Schlick
authors.affiliation: Department of Orthopedics, Physical Medicine and Rehabilitation, Ludwig-Maximilians-University Munich Marchioninistr. 15, 81377 Munich, Germany. Electronic address: Josef.Ilmberger@med.uni-muenchen.de.
authors.forename: J R
authors.initials: JR
authors.lastname: Ilmberger
authors.affiliation: Department of Neurology, Ludwig-Maximilians-University Munich, Marchioninistr. 15, 81377 Munich, Germany. Electronic address: Kai.Boetzel@med.uni-muenchen.de.
authors.forename: K
authors.initials: K
authors.lastname: Bötzel
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001132:Arm / Q000502:physiology*; D001696:Biomechanical Phenomena; D016022:Case-Control Studies; D005080:Exercise Test; D005260:Female; D005684:Gait / Q000502:physiology*; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology*; D012016:Reference Values; D012737:Sex Factors; D016138:Walking / Q000502:physiology*