The Effect of External Loads and Cyclic Loading on Normal Patellofemoral Joint Signals.

K. O. Ladly; C. B. Frank; G. D. Bell; Y. T. Zhang; R. M. Rangayyan

doi:10.14429/dsj.43.4223

K. O. Ladly The University of Calgary, Alberta
C. B. Frank The University of Calgary, Alberta
G. D. Bell The University of Calgary, Alberta
Y. T. Zhang The University of Calgary, Alberta
R. M. Rangayyan The University of Calgary, Alberta

DOI: https://doi.org/10.14429/dsj.43.4223

Keywords: Vibroarthrography, Chondromalacia patella .

Abstract

Pain over the anterior portion of the knee joint is a common clinical complaint. A condition known as 'chondromalacia patella' (softening of the cartilage under the patella), which frequently causes anterior knee pain is difficult to diagnose and monitor. Vibrations detected by a contact transducer over the patellofemoral joint may be useful in the assessment of chondromalacia patella. This paper utilised this technique known as vibroarthrography (VAG), to study two potential sources of variability of the normal patellofemoral joint signal. The effect of increased muscular force on the VAG signal was measured by externally loading the joint. The effect of load history (cyclic loading) on the VAG signal was determined by comparing signals before, during, and after application of weights under similar cyclic loading conditions. Results indicated that external loading of the patellofemoral joint caused only minor signal variation. Cyclical loading of the joint, on the other hand, was determined to be a major source of variability of the normal patellofemoral joint signal, which must be controlled in future VAG tests.

Author Biographies

K. O. Ladly, The University of Calgary, Alberta

Ms KO Ladly received MSc from the University of Calgary, Canada, in 1992. She is currently working as a research assistant at the Sport Medicine Centre of the same university.

C. B. Frank, The University of Calgary, Alberta

Dr CD Frank received MD in 1976 from the University of Calgary , Canada, and graduated in 1980 with his FRCS(C) in Orthopaedic Surgery from the same university. He is presently a Professor in the Department of Surgery and is the Chairman of the Division of Orthopaedics at the University of Calgary.

G. D. Bell, The University of Calgary, Alberta

The University of Calgary, Calgary, Alberta.

Y. T. Zhang, The University of Calgary, Alberta

Mr YT Zhang received MSc in Communications from the Department of Electronics, Shandon. University, Jinan , China, in 1981, and PhD in Biomedical Engineering from the University of New Brunswick', Fredericton, ,Canada, in 1990. He is at present a Research Assistant Professor of Human Performance Laboratory at the University of Calgary. His research interests include biomedical signal processing , modellin of electro-mechano-physiological events, neuromuscular systems , adaptive signal processing neural networks, and communications. Dr Zhang is a member of the Canadian Medical an: Biological Engineering Society.

R. M. Rangayyan, The University of Calgary, Alberta

Dr RM Rangayyan received BE in Electronics and Communication in 1976 from the University of Mysore and PhD in Electrical Engineering from the Indian Institute of Science,Bangalore, in 1980. He is at present a Professor with the Department of Electrical Engineering, University of Calgary , Canada. He has taught courses in the areas of electrical circuits, communication, digital signal processing , digital filters, digital image processing, and engineering communication. His interests are in the areas of digital signal and image processing, biomedical analysis, and medical imaging and image analysis. He is an Associate Editor of the IEEE Transactions on Biomedical Engineering .