Study of anatomical landmark sampling error effect on motion measurement reproducibility for Orthopaedic physical examination assisting system

Jun Okamoto, Yu Kumasaka, Kazuya Kawamura, Tomoyuki Matsumoto, Seiji Kubo, Hirotsugu Muratsu, Masahiro Kurosaka, Masakatsu G. Fujie

Research output: Contribution to journalArticle


We have been developing the Orthopaedic physical examination assisting system using magnetic position tracker to quantitate knee laxity diagnosis. In this study, to investigate the influence of anatomical landmark sampling error for bone coordinate registration, reproducibility verification simulation was done. Firstly, the motion data of imitation bones was acquired using the system and set as a reference data. To get the error motion data, virtual error vectors were added on the reference sampling points and new motion data was recomputed. Evaluation was executed by comparison with the reference data and recomputed data. The evaluation results lead improvement methods of measurement reproducibility as follows. 1. It is important to point the landmarks proximal to the knee carefully because the contribution of the motion error is higher than the distal landmarks. 2. To reduce the registration error, thigh and shank receivers should be set close to the knee as possible. 3. If the allowance area of the sampling error is in 2.0 mm diameter circle, Diagnosis error using IKDC Knee examination form is approximately 20 %.

Original languageEnglish
Pages (from-to)3780-3793
Number of pages14
JournalNihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C
Issue number782
Publication statusPublished - 2011
Externally publishedYes



  • Bio-Motion
  • Biomechanics
  • Knee laxity diagnosis
  • Magnetic tracker
  • Medical and welfare assistance
  • Medical quantitation
  • Orthopaedic physical examination

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Industrial and Manufacturing Engineering

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