title: Frame-difference analysis of video-recorded laser-beam projections.
abstract: Laser beams have been applied in many human motion research contexts to project movements in specific motor tasks. Currently, there are no objective analysis methods for laser projection recordings. The principal aim of this study was to investigate the feasibility of quantifying motion by applying frame differencing and image analysis methods to video streams of laser beam projections. The laser projection was controlled by a mechanical device that produced pseudo random rotations. The 2D motion recorded by the video was compared with recordings obtained with an electromagnetic system where a sensor was fixed to the same device as the laser. High correlations in the time and frequency domains were found between the methods. We conclude that the proposed method can accurately quantify complex motion patterns from laser beam projections.
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Division Physiotherapy, Faculty of Health Education and Social Work, Sør-Trøndelag University College, Trondheim, Norway. Electronic address: havard.loras@hist.no.
authors.forename: H
authors.initials: H
authors.lastname: Lorås
authors.affiliation: Department of Biomedical Engineering & Informatics, Radiation Science, Umeå University, Umeå, Sweden. Electronic address: fredrik.ohberg@radfys.umu.se.
authors.forename: F
authors.initials: F
authors.lastname: Öhberg
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. Electronic address: ottar.vasseljen@ntnu.no.
authors.forename: O
authors.initials: O
authors.lastname: Vasseljen
authors.affiliation: Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway; Division Physiotherapy, Faculty of Health Education and Social Work, Sør-Trøndelag University College, Trondheim, Norway. Electronic address: ann.k.stensdotter@hist.no.
authors.forename: A K
authors.initials: AK
authors.lastname: Stensdotter
mesh_terms: D001696:Biomechanical Phenomena; D055590:Electromagnetic Phenomena; D006801:Humans; D007834:Lasers; D009068:Movement / Q000502:physiology*; D009664:Norway; D036301:Qualitative Research; D014741:Video Recording
keywords: Human motion; Kinematics; Motor control; Movement analysis