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Arthritis
Volume 2011 (2011), Article ID 571519, 9 pages
http://dx.doi.org/10.1155/2011/571519
Research Article

The Influence of Radiographic Severity on the Relationship between Muscle Strength and Joint Loading in Obese Knee Osteoarthritis Patients

1Clinical Motor Function Laboratory, The Parker Institute, Frederiksberg Hospital, 2000 Frederiksberg, Denmark
2Department of Medicine and Anatomy, Panum Institute, University of Copenhagen, 2200 Copenhagen, Denmark
3Department of Radiology, Frederiksberg Hospital, 2000 Frederiksberg, Denmark

Received 14 December 2010; Revised 15 February 2011; Accepted 17 February 2011

Academic Editor: K. L. Bennell

Copyright © 2011 Jens Aaboe et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective. To investigate the relationship between knee muscle strength and the external knee adduction moment during walking in obese knee osteoarthritis patients and whether disease severity influences this relationship. Methods. This cross-sectional study included 136 elderly obese (BMI>30) adults with predominant medial knee osteoarthritis. Muscle strength, standing radiographic severity as measured by the Kellgren and Lawrence scale, and the peak external knee adduction moment were measured at self-selected walking speed. Results. According to radiographic severity, patients were classified as “less severe” (KL 1-2, N=73) or “severe” (KL 3-4, N=63). A significant positive association was demonstrated between the peak knee adduction moment and hamstring muscle strength in the whole cohort (P=.047). However, disease severity did not influence the relationship between muscle strength and dynamic medial knee joint loading. Severe patients had higher peak knee adduction moment and more varus malalignment (P<.001). Conclusion. Higher hamstring muscle strength relates to higher estimates of dynamic knee joint loading in the medial compartment. No such relationship existed for quadriceps muscle strength. Although cross sectional, the results suggest that hamstrings function should receive increased attention in future studies and treatments that aim at halting disease progression.