Upper extremity stress fractures do occur, but they are uncommon. When stress fractures occur in the upper extremity its commonly in the upper torso and is caused by muscle forces.The population that has the highest risk for stress fractures is athletes and military recruits who are participating in repetitive, high intensity training. Sports and activities that have excessive, repetitive ground reaction forces have the highest incidence of stress fractures. The site at which the stress fracture occurs depends on the activity/sports that the individual participates in.Women are more at risk for stress fractures than men due to factors such as lower aerobic capacity, reduced muscle mass, lower bone mineral density, among other anatomical and hormone-related elements. Women also have a two- to four-times increased risk of stress fractures when they have amenorrhea compared to women who are eumenorrheic. Reduced bone health increases the risk of stress fractures and studies have shown an inverse relationship between bone mineral density and stress fracture occurrences. This condition is most notable and commonly seen on the femoral neck. Other animals
Dinosaurs
In 2001, Bruce Rothschild and other paleontologists published a study examining evidence for stress fractures in theropod dinosaurs and analyzed the implications such injuries would have for reconstructing their behavior. Since stress fractures are due to repeated events they are probably caused by expressions of regular behavior rather than chance trauma. The researchers paid special attention to evidence of injuries to the hand since dinosaurs hind feet would be more prone to injuries received while running or migrating.
Labour or labor may refer to:

Childbirth, the delivery of a baby
Labour (human activity), or work
Manual labour, physical work
Wage labour, a socioeconomic relationship between a worker and an employer
Organized labour and the labour movement, consisting principally of labour unions
The Labour Party (UK)

Literature
Labor (journal), an American quarterly on the history of the labor movement
Labour/Le Travail, an academic journal focusing on the Canadian labour movement
Labor (Tolstoy book) or The Triumph of the Farmer or Industry and Parasitism (1888)

Places
La Labor, Honduras
Labor, Koper, Slovenia

Other uses
Labor (album), a 2013 album by MEN
Labor (area), a Spanish customary unit
"Labor", an episode of TV series Superstore
Labour (constituency), a functional constituency in Hong Kong elections
Labors, fictional robots in Patlabor

People with the surname
Earle Labor (born 1928), professor of American literature
Jérémy Labor (born 1992), French footballer
Josef Labor (1842–1924), Austrian musician and composer

See also
Labor Day (disambiguation)
Labour law
Labour Party (disambiguation)
Work (disambiguation)
All pages with titles beginning with Labour
All pages with titles containing Labour
All pages with titles beginning with Labor
All pages with titles containing Labor