What is a grade of 2+ on the Brush/Stroke Test?

• A. No wave produced on downstroke
• B. Small wave on medial side with downstroke
• C. Larger bulge on medial side with downstroke
• D. Effusion spontaneously returns to medial side after upstroke

Answer: (D)

In the Brush/Stroke Test, the amount of knee fluid is judged by how the wave moves when you sweep the knee and watch the medial suprapatellar area. For a grade 2+, the defining sign is that, after you perform the upstroke, the effusion returns to the medial side on its own. This indicates a moderate amount of intra-articular fluid that shifts with the stroke but reseats medially once the stroke ends.

The other patterns describe smaller or larger immediate responses during the stroke itself (no wave, a small wave, or a larger bulge), but they don’t capture the specific rebound behavior after the upstroke that characterizes the 2+ grade.