THE EFFECTS OF QUADRICEPS-STRENGTHENING EXERCISE ON QUADRICEPS MUSCLE BIOMECHANICS DURING LOCOMOTION IN ADULTS WITH KNEE OSTEOARTHRITIS.

Knee Osteoarthritis (OA) is a disease characterized by knee joint deterioration and pain, while also being associated with altered knee joint mechanics and quadriceps strength deficits. Research investigating the effects of quadriceps-strengthening exercise on knee OA has shown improvements in symptoms, function, and strength, but minimal changes to joint mechanics. It is speculated that altered quadriceps muscle biomechanics are the mechanism responsible for this improvement in symptoms, though this concept is untested. The purpose of this study is to examine the effects of quadriceps strengthening exercise on quadriceps muscle biomechanics during level walking, stair ascent, and stair descent in adults with knee osteoarthritis. Three-dimensional kinematic, ground reaction force, isokinetic strength, and WOMAC data were collected on 10 adults with uni- or bi-lateral knee OA. During the 12-week period between the testing procedures, 6 adults participated in strengthening exercise, while the other 4 adults went untrained. Quadriceps biomechanics were quantified using kinetic data collected during level walking, stair ascent, and stair descent tasks in combination with a mathematical knee model. A 2x2 repeated measures ANOVA (p<0.05) was used to analyze each symptomatic, strength, joint kinetic, and muscle biomechanics parameter