Ballottement test

Original Editor - Uchechukwu Chukwuemeka Top Contributors - Anas Mohamed and Vidya Acharya  

Purpose

The ballottement test also is known as the Patella tap test or the ballottement patella sign. Ballottement means “a tossing about.” and it was coined from a french word. The test is usually used to check for knee joint effusion.

Technique

• To start the test, the patient/client lies supine on an examination table with knee exteded.

• The therapist uses the non-dominant hand to apply a series of downwards stroke from thigh to leg. This moves any fluid in the thigh to the knee. And then firmly grasps the upper part of the knee just above the patella.
• One finger or the thumb of the dominant hand is used to push the patella backward against the femur.
• An increased patella waving motion or spongy joint feeling suggests the test is positive for joint effusion.
• Then the test is repeated on the contralateral joint for comparison.

Evidence

Patellar tap has been shown to have an inter-observer kappa agreement of −0.02 to 0.75 with sensitivity ranging 18.2–85.7% and specificity 35.3–93.3%, both higher with larger effusions.