Fig. 1

Experimental setting. The ultrasound probe was placed in an oblique sagittal position (a). The largest diameter of the supraspinatus muscles was detected using b-mode ultrasound (b). SWE measurement was performed at this location in a parallel orientation of the transducer to the muscle fibers (c). The velocity of shear wave propagation was measured at 10–15 points in the ROI. The measurement was repeated 5 times to cover almost the whole cross section area of the muscle. To ensure spectroscopic measurement at the same location the point of measurement was marked with a MRI visible gel capsule fixed to the patient’s skin