Patellar Tap Test (Ballotable Patella)

Purpose[edit | edit source]

Patella tap test or ballottement test is used to examine the knee swelling or knee effusion.

This test is also know as dancing knee sign.

Technique[edit | edit source]

Step1. Patient in supine position and knee extended.

Step2. Therapist one hand is push down front of the leg to the top of the patella this moves any fluid in the thigh to the knee.

Step3. keep pressure on with other hand gently tap over the patella.

Step4. Positive sign when floating or bouncing of patella occurs and indicates knee joint effusion.

Step5. Always compare with normal side or opposite side.

References[edit | edit source]

  1. Patella tap test - Ballottement test. Clinical Examination Videos. Available from:

.2. David J. Magee. Orthopedic Physical Assessment. 6th edition. Elsevier. 2014.