Fig. 3.

Ultrasonography assessments of the suprapatellar bursa (SPB) expansion on the non-activated quadriceps (NAQ) method (Fig. 3-A) and the isometric quadriceps contraction (IQC) method (Fig. 3-B). The anterior-posterior dimension of the SPB (bar marked by arrow) was measured vertically to the femoral bone. The target point for the needle to successfully enter the SPB is this measurement point immediately proximal to the suprapatellar fat pad (SPF). The SPB expands maximally in the anterior-posterior plane at this point, which is an area with relatively little obstruction.