were once called musculoskeletal stress markers, but now widely named entheseal changes. These changes were widely used to study activity-patterns, but research has shown that processes associated with aging have a greater impact than occupational stresses. It has also been shown that geometric changes to bone structure (described above) and entheseal changes differ in their underlying cause with the latter poorly affected by occupation. Joint changes, including osteoarthritis, have also been used to infer occupations but in general these are also manifestations of the aging process. Markers of occupational stress, which include morphological changes to the skeleton and dentition as well as joint changes at specific locations have also been widely used to infer specific (rather than general) activities. Such markers are often based on single cases described in clinical literature in the late nineteenth century. One such marker has been found to be a reliable indicator of lifestyle: the external auditory exostosis also called surfer's ear, which is a small bony protuberance in the ear canal which occurs in those working in proximity to cold water. One example of how these changes have been used to study activities is the New York African Burial Ground in New York. This provides evidence of the brutal working conditions under which the enslaved labored; osteoarthritis of the vertebrae was very common, even among the young. The pattern of osteoarthritis combined with the early age of onset provides evidence of labor that resulted in mechanical strain to the neck. One male skeleton shows stress lesions at 37 percent of 33 muscle or ligament attachments, showing he experienced significant musculoskeletal stress. Overall, the interred show signs of significant musculoskeletal stress and heavy workloads, although workload and activities varied among different individuals. Some individuals show high levels of stress, while others do not. This references the variety of types of labor (e.g., domestic vs. carrying heavy loads) labor that enslaved individuals were forced to perform. Injury and workload Fractures to bones during or after excavation will appear relatively fresh, with broken surfaces appearing white and unweathered. Distinguishing between fractures around the time of death and post-depositional fractures in bone is difficult, as both types of fractures will show signs of weathering. Unless evidence of bone healing or other factors are present, researchers may choose to regard all weathered fractures as post-depositional. Evidence of perimortal fractures (or fractures inflicted on a fresh corpse) can be distinguished