Development and application of a six degree-of-freedom knee joint goniometer

Research Project

Project/Area Number	60870051
Research Category	Grant-in-Aid for Developmental Scientific Research
Allocation Type	Single-year Grants
Research Field	Orthopaedic surgery
Research Institution	Tokyo Medical and Dental University
Principal Investigator	ISHIDA Akimasa Tokyo Medical and Dental Univ., Professor, 医用器材研究所, 教授 (60016540)
Co-Investigator(Kenkyū-buntansha)	KUNO Akira Toyota Central Research & Development Laboratories, Inc., 試作部, 次長 YAMAMOTO Haruyasu Tokyo Medical and Dental Univ., Associate Professor, 医学部, 助教授 (10092446) TAKAHASHI Makoto Tokyo Medical and Dental Univ., Instructor, 医用器材研究所, 助手 (10154858)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥3,700,000 (Direct Cost: ¥3,700,000) Fiscal Year 1986: ¥1,200,000 (Direct Cost: ¥1,200,000) Fiscal Year 1985: ¥2,500,000 (Direct Cost: ¥2,500,000)
Keywords	Goniometer / Knee joint / 不安定性 / 膝の動揺性
Research Abstract	To quantify manual test of knee joint instability, we developed a six dgree-of-freedom goniometer and applied it to clinical use. first, we gave mathematical definition of internal-external rotation (axial rotation). Suppose that <phi> , <theta> , <psi> denote Eulerian angles respectively. According to our definition, net axial rotation is given by integrating angular velocity <omega> =-(d <phi> )/(dt)・sin <theta> +(d <psi> )/(dt) Second, we developed a six degree-of-freedom knee goniometer. We used four sensors which detect abduction-adduction, flexion-extention, internal-external rotation angles and anterior-posterior displacement. Outputs of these sensors correspond to above-mentioned angles and displacement directly and no processing and calculation is necessary. Using this goniometer, we tried anterior-posterior drawer test, varus-valgus stress test on normal ten knees and three injured knees. Though amount of data are not enough, results of injured knees were specific to injured ligaments. And good agreement was obtained between these results and roentgenographic measurement. We are now developing unrestrained measurement apparatus of knee joint motion which adopts two inclinometers and one magnetic sensor.