When planning ultrasound therapy for the insertion of the biceps femoris tendon, where should the transducer be placed?

• A. Slightly proximal to the fibula head
• B. Slightly proximal to the pes anserine region
• C. Slightly proximal to the tibial tuberosity
• D. Slightly distal to the popliteal fossa

Answer: (A)

Imaging the tendon insertion requires aligning the probe to follow the distal tendon to its attachment. The biceps femoris tendon attaches to the fibular head on the lateral knee, so you want to place the ultrasound transducer along the lateral knee slightly above the fibular head to view the tendon in a longitudinal view as it approaches and inserts at that site. This position lets you visualize the distal tendon fibers and their attachment-point for accurate assessment of the insertion.

The other regions are not where the biceps femoris inserts (pes anserine is medial with other tendons, tibial tuberosity relates to the patellar tendon, and the popliteal area is posteriorly located). So the best placement is slightly proximal to the fibular head.