I would not recommend using shockwave therapy (ESWT) in the region that you are thinking of.
ESWT is a pressure disturbance technique (generated by either electrohydraulic, electromagnetic or piezoelectric methods).
The primary evidence of efficacy is in chronic and calcific tendinopathy where the therapy stimulates healing via conversion of shock waves to release of biochemical factors such as TGF-beta-1. It has been shown also to promote vascularisation and suppress nociception.
Although I suspect the following are based more in theoretical risk, the contraindications are reported to include lungs, eyes, brain, major blood vessels and major nerves, open wounds, implanted devices and epiphyseal plates. Relative contraindications are reported to be genitalia, pregnancy, clotting disorders, anti-coagulant therapy, joint replacement, infection, cancer and recent corticosteroid injection.
I hope this helps.