A new study suggests U.S. service members are at high risk of early disability from osteoarthritis due to the job's extreme physical demands, The Wall Street Journal reported.

An estimated 26.9 million American adults have osteoarthritis, a condition associated with traumatic joint injuries and the most common form of arthritis in older individuals, according to the study in Arthritis and Rheumatism.

From 1999 to 2008, first-time diagnoses of osteoarthritis were recorded in active duty service members from the U.S. Army, Navy, Air Force and Marine Corps. On average, 10,827 cases were diagnosed annually among about 1.4 million service members.

Osteoarthritis rates were 26 percent higher in members aged 20 to 24 than in the general population, and twice as high in those over 40, the study found.

The U.S. Army had the highest rate of osteoarthritis, followed by the Air Force, Marine Corps and Navy. Regular knee and hip bending plus strenuous physical activity likely contribute to higher osteoarthritis rates in service members, the study concluded.

It was not known how many cases of osteoarthritis in the study were caused by trauma.

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