- Have a known active infection in the body; Imprisoned; Pregnant ; Cognitively impaired ; Fracture in humerus or tibia, or significant trauma to the site; Excessive tissue and/or absence of adequate anatomical landmarks at proximal humerus and proximal tibia IO insertion sites; Infection in target area; Humeral/tibial IO insertion in past 48 hours, prosthetic limb or joint or other significant orthopedic procedure in humerus or tibia; Current use of anti-coagulants; Current cardiac condition requiring pacemaker or anti-arrhythmic drugs; Prior adverse reaction to lidocaine; History of impaired renal function; Prior adverse reaction to contrast media; Allergy to iodine containing medications; Allergy to shellfish; Have taken analgesics/anesthetics the day of in-house study procedures; Volunteers with any of the following characteristics may be excluded from the study at the discretion of the PI; Allergy to any food or drug; History of impaired hepatic function; History of cardiac disease; History of pheochromocytoma