VALGUS-VARUS MOTION OF THE KNEE IN NORMAL LEVEL WALKING AND STAIR CLIMBING

Objective. The knee valgus-varus moment and the knee angles were compa red between normal level walking and stair climbing. Design. Ten healt hy subjects were tested for ascent, descent, and level walking. Backgr ound. An understanding of the normal valgus-varus motion of the knee d uring stair climbing is needed to apply biomechanical analysis of stai r climbing as a evaluation tool for knee osteoarthritis patients. Meth ods. A motion analysis system, three force plates, and a flight of sta irs were used to collect kinematic and kinetic data. The knee angles a nd moments were calculated from the collected kinematic and kinetic da ta. Results. The knee varus angle for the maximum knee valgus moments in stair climbing was significantly greater than that in level walking . The knee valgus moment was significantly correlated to ground reacti on forces and knee valgus-varus angle during stair climbing and level walking. Conclusions. There is a coupling between the knee valgus-varu s motion and flexion-extension motion. Ground reaction forces are the major contributors to the within-subject variation in the knee valgus- varus moment during stair climbing and level walking. The knee valgus- varus angle is a major contributor to the between-subject variation in the knee valgus moment during stair climbing and level walking. Relev ance This study provides a basic understanding of the valgus-varus mot ion of the knee during level walking and stair climbing. The results s upport the use of biomechanical analysis of stair climbing as a clinic al evaluation tool for patients with knee osteoarthritis. (C) 1997 Els evier Science Ltd.