Humerus fracture also cause deformity, and they typically limit the ability to flex the elbow. Humerus fractures usually occur after physical trauma, falls, excess physical stress, or pathological conditions. Falls that produce humerus fractures among the elderly are usually accompanied by a preexisting risk factor for bone fracture, such as osteoporosis, a low bone density, or vitamin B deficiency. Proximal humerus fractures most often occur among elderly people with osteoporosis who fall on an outstretched arm. Less frequently, proximal fractures occur from motor vehicle accidents, gunshots, and violent muscle contractions from an electric shock or seizure. Other risk factors for proximal fractures
Humerus fracture include having a low bone mineral density, having impaired vision and balance, and tobacco smoking. A stress fracture of the proximal and shaft regions can occur after an excessive amount of throwing, such as pitching in baseball. Middle fractures are usually caused by either physical trauma or falls. Physical trauma to the humerus shaft tends to produce transverse fractures whereas falls tend to produce spiral fractures. Metastatic breast cancer may also cause fractures in the humerus shaft. Long spiral fractures of the shaft that are present in children may indicate physical abuse. Distal fractures usually occur as a result of