title: An iPhone application for upper arm posture and movement measurements.
abstract: There is a need for objective methods for upper arm elevation measurements for accurate and convenient risk assessments. The aims of this study were (i) to compare a newly developed iOS application (iOS) for measuring upper arm elevation and angular velocity with a reference optical tracking system (OTS), and (ii) to compare the accuracy of the iOS incorporating a gyroscope and an accelerometer with using only an accelerometer, which is standard for inclinometry. The iOS-OTS limits of agreement for static postures (9 subjects) were -4.6° and 4.8°. All root mean square differences in arm swings and two simulated work tasks were <6.0°, and all mean correlation coefficients were >0.98. The mean absolute iOS-OTS difference of median angular velocity was <13.1°/s, which was significantly lower than only using an accelerometer (<43.5°/s). The accuracy of this iOS application compares well to that of today's research methods and it can be useful for practical upper arm measurements.
authors.affiliation: Unit of Ergonomics, School of Technology and Health, KTH Royal Institute of Technology, Stockholm, Sweden. Electronic address: liyuny@kth.se.
authors.forename: Liyun
authors.initials: L
authors.lastname: Yang
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Wilhelmus J A
authors.initials: WJA
authors.lastname: Grooten
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Forsman
mesh_terms: D061725:Accelerometry / Q000379:methods*; D000328:Adult; D001132:Arm / Q000502:physiology*; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D063731:Mobile Applications; D009068:Movement; D011187:Posture / Q000502:physiology*; D015203:Reproducibility of Results; D000068997:Smartphone; D055815:Young Adult
keywords: Accelerometer; Gyroscope; Work-related musculoskeletal disorders