Proximal humerus fracture Proximal humerus fracture A proximal humerus fracture is a break of the upper part of the bone of the arm (humerus). Symptoms include pain, swelling, and a decreased ability to move the shoulder. Complications may include axillary nerve or axillary artery injury. The cause is generally a fall onto the arm or direct trauma to the arm. Risk factors include osteoporosis and diabetes. Diagnosis is generally based on X-rays or CT scan. It is a type of humerus fracture. A number of classification systems exist. Treatment is generally with an arm sling for a brief period of time followed by
Effect of spaceflight on the human body on the bones, there is a rapid increase in bone loss, from 3% cortical bone loss per decade to about 1% every month the body is exposed to microgravity, for an otherwise healthy adult. The rapid change in bone density is dramatic, making bones frail and resulting in symptoms which resemble those of osteoporosis. On Earth, the bones are constantly being shed and regenerated through a well-balanced system which involves signaling of osteoblasts and osteoclasts. These systems are coupled, so that whenever bone is broken down, newly formed layers take its place—neither should happen without the other, in a healthy