Meta analyses are only as good as the quality of the underlying studies, which in this case is not very good. Some studies published in quality journals suggest that berberine's positive effects may stem from the fact that it activates AMP-Kinase, which is what metformin does.
Figure 34-2 Medial thigh furrow (wide line) is surface depression extending from proximal anterior to distal posterior thigh. Furrow divides area into medial thigh (proximal) and medial knee (distal). Figure 34-3 Full view of medial thigh/knee contour drawings. A, Right medial thigh, with patient standing and raising left thigh. This view demonstrates medial thigh furrow. B, Left medial thigh, with patient standing and raising right thigh.
Vastus Medialis Anatomy Study: Origin, Insertion, Action and Innervation. Origin: Lower part of the intertrochanteric line, along the spiral line to the medial lip of the linea aspera and the medial intermuscular septum and the aponeurosis of adductor magnus.