Which exam finding is typical in knee OA?

• A. Extension restricted more than flexion
• B. Normal strength
• C. Flexion restricted more than extension
• D. Increased range of motion

Answer: (C)

In knee OA, the pattern of motion loss reflects the degenerative changes around the joint. The cartilage wears, osteophytes form, and the joint reacts with mild effusion and soft-tissue tightness, all of which tend to impede bending the knee more than straightening it. So flexion becomes limited while extension remains relatively preserved in early to mid-stage disease. This means patients often have trouble deep-knee bending or squatting, but can still straighten the leg, with extension becoming restricted only in more advanced, fixed-flexion deformities. Strength can be affected by disuse or pain, but the characteristic exam finding is greater restriction of flexion than of extension.