<prompt> Fracture neck femur cause of non-unionsmokingPoor nutrition of the patientInjury to blood supply with shearing stressOld age and osteoporosis  <response>: Estimates of wall shear stress at various locations in the circulation have been level of shear stress due to alterations in blood flow rate and vessel wall diameter.in part, in vivo responses of injured or activated endothelium to shear stress. 