Embodiments of the present invention disclose a wireless network device, a wireless network system and a method of controlling selection of routings. The barrier has an inside wall, an outside wall and a space between the inside and outside walls. In such an embodiment, the method can comprise determining a strength of the femur, by a processor and based on the elastic modulus, the cortical bone yield strength, the stress level \u03c3min, and the post-yield stress-strain slope of the proximal femur.