In 2005, a 10-day examination of the skeleton, led by forensic anthropologist Douglas Owsley, revealed that Kennewick Man had arthritis in his right elbow, both of his knees, and several vertebrae but not severe enough to be crippling.Owsley discovered that Kennewick Man had also suffered some trauma in his lifetime, which was evident by a fractured rib that had healed, a depression fracture on his forehead, and a similar indentation on the left side of the head, and a spear jab that healed.Skulls older than 8000 years old have been found to possess greater physical diversity than those of modern Native Americans.The origin of that diversity, whether from different lineages or local adaptation, is a matter of debate.Kennewick Man was found to be right-handed, as the bones of the right arm are noticeably larger than the left. conducted a graphic comparison, including size, of Kennewick Man to eighteen modern populations.
Kennewick Man was found to have been deliberately buried.Kennewick Man became the subject of a controversial nine-year court case between the United States Army Corps of Engineers (USACE), scientists, and Native American tribes who claimed ownership of the remains.Under NAGPRA, the tribes had the right to rebury the remains of Kennewick Man and to refuse scientific study of the man they referred to as "the Ancient One".In this case, the archaeologists who studied the bones, James Chatters and Douglas Owsley, the latter with the Smithsonian Institution, both asserted that the bones were only distantly related to today's Native Americans.
They also said the remains had features that more closely resembled Polynesian or Southeast Asian peoples, a finding that would exempt the bones from NAGPRA.
The Umatilla people and other tribes demanded the remains returned for reburial under the federal Native American Graves Protection and Repatriation Act (NAGPRA).