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 of muscle fibre prominent in muscles also change. Slow twitch endurance fibres used to maintain posture are replaced by fast twitch rapidly contracting fibres that are insufficient for any heavy labour. Advances in research on exercise, hormone supplements and medication may help maintain muscle and body mass. Bone metabolism also changes. Normally, bone is laid down in the direction of mechanical stress. However, in a microgravity environment there is very little mechanical stress. This results in a loss of bone tissue approximately 1.5% per month especially from the lower vertebrae, hip and femur. Due to microgravity and the decreased load