Fig. 5
From: A guide for standardized interpretation of lumbar multifidus ultrasonography; an observational study
40 year old specimen (A) Paramedian sagittal reconstruction of LM origin, 2 cm lateral to the midsagittal plane, as shown in inset. S1-S3, vertebral bodies S1-3; SN1-2, sacral spinal nerves S1-2; LM = Lumbar multifidus; PM = piriformis muscle; GM = gluteus maximus. (B) Ultrasonographic view with linear transducer 12 MHz in human volunteer, with probe in similar paramedian sagittal plane (see inset right lower corner). White arrows indicate the dorsal surface of the sacrum (S). White arrowheads (Figs A, B) indicate the erector spinae aponeurosis (ESA)