Study on the Effects of Different Stair-Descending Methods on Knee Angle, Joint Moment and Joint Force

Abstract

[Purpose] In general, people with bilateral osteoarthritis descend stairs sideways or backwards as compensatory movements. However, to the best of our knowledge, no studies have investigated these movements. The objective of the present study was to ascertain the effects of descending forwards and descending backwards on kinetic changes in the knee joint, to ascertain the optimal stair descending method for minimizing stress on the knee joint. [Subjects] Subjects were 30 adult women with no orthopedic or neurological disorders. [Methods] With step heights (riser heights) of 10, 15, 20 and 25 cm, changes in knee flexion angle, extension moment and joint force were measured when descending forwards and descending backwards using a three dimensional motion analysis system. [Results] Peak knee flexion angle, peak knee extension moment and peak knee joint forces observed in descending stairs backwards were smaller than those in the descending forwards action. [Conclusion] The present results suggest that descending stairs backwards for osteoarthritis patients is effective in protecting the knees, alleviating pain and acquiring compensatory movements.