%0 Journal Article %T Interrater Reproducibility of Knee Movement Analyses during the Stance Phase: Use of Anatomical Landmark Calibration with a Rigid Marker Set %A Takashi Fukaya %A Hirotaka Mutsuzaki %A Yasuyoshi Wadano %J Rehabilitation Research and Practice %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/692624 %X Objective. Measurements of knee joint movement in gait analysis may result in large errors caused by misplacement of reflective markers by the testers. To properly understand the measurement results, it is important to guarantee the reliability of the measurement method used for the purpose. The aim of this study was to confirm the interrater reproducibility of a measurement method with a rigid marker set (RMS). Methods. The study subjects were four healthy adults, and the testers were three physical therapists. The interrater reproducibility of the measurements was verified by using the coefficient of multiple correlations (CMCs) and the standard error of measurement (SEM). Results. The average CMCs values of 4 subjects in knee joint movement at the stance phase were greater than 0.8, and the average SEM values of 4 subjects in knee joint movement at the stance phase were also relatively good (maximum error: 2.42¡ã). Conclusion. Based on these results, the measurement method with estimation of anatomical landmarks using the RMS can prevent misplacement during attachment of the reflective markers, as long as the testers have sufficient experience in attaching reflective markers. 1. Introduction Gait analysis for musculoskeletal disorders and neuromuscular conditions (cerebral palsy, adult hemiplegia, and Parkinson¡¯s disease) has been widely applied both clinically and in research, and measurements using infrared reflective markers are an established technique for gait analysis [1]. In general, motion analysis based on a camera system is used to define a rigid body model in three-dimensional space. When the changes in joint movement are calculated by a rigid body model, the reflective markers are stuck on anatomical landmarks of each segment, and the changes in joint movement are calculated by the positions of the reflective markers. However, when a bone projection is used as an anatomical landmark, it has been reported that individual reflective markers stuck on the skin surface will move independently owing to modification of the soft tissue organization according to the shock in the early stance phase or the influence of muscle contraction [2]. While measurements of marker sets mounted on bone pins are comparatively accurate, the procedure is invasive and difficult to use in clinical settings [3, 4]. In addition, three markers mounted on rigid plates (rigid marker set (RMS)) affixed to the thigh and shank have been used to counter the problems associated with skin-mounted marker sets [5]. Since the infrared reflective markers are fixed to rigid plates %U http://www.hindawi.com/journals/rerp/2013/692624/