A network of trabecular fibers run through the head and neck of the femur and are extremely important during function, especially during single-limb stance. These fibers allow the proximal femur to withstand both compression forces (blue regions) and tension (red regions) and undergo more deformation (change in shape) than the hard cortical bone found in the shaft of the femur.
Although this region is designed well from an architectural standpoint, it does demonstrate a zone of weakness where trabecular fibers cross at suboptimal angles leaving the bone vulnerable to injury in certain instances such as falls. When this type of fracture does occur it is usually in cases of high force collisions (motor vehicle accidents, sports, etc) or in situations where bone health has been compromised such as seen with osteoporosis.
This is yet another example that illustrates the importance of a resistance training program and a sound nutritional plan in order to optimize bone health and reduce the risk of fracture. Populations that are most at risk of suffering this injury include older adults, especially females, athletes who spend large amounts of time exercising in environments that reduce bone stress (cycling and swimming) and females who fall in the ‘female athlete triad’ category (osteoporosis, absence of a menstrual cycle and disordered eating).