ST. PAUL, Minn. — Thousands of Minnesota soldiers are returning from war with chronic pain from injuries that leave many of them impaired and even disabled, and there’s been a steep increase in such injuries over the past decade.

For example, according to an analysis by Minnesota Public Radio of Department of Veterans Affairs data (http://bit.ly/118W3Ww ), doctors at VA hospitals in Minneapolis, St. Cloud, Fargo, N.D., and Sioux Falls, S.D., saw veterans with joint disorders at least 35,000 times in 2012, a 133 percent increase over 2003.

Nationally, according to the federal Veterans Benefits Administration, musculoskeletal conditions were the No. 1 service-connected disability for veterans every year from 2007 to 2011.

Although some soldiers are injured in combat, others are hurt doing other dangerous jobs overseas, and some develop pain from carrying the heavy weight of the very equipment meant to protect them.

Among those in constant pain is Patrick Nelson, 30, of Eden Prairie, a veteran of three tours in Iraq and Afghanistan. Doctors diagnosed the former Army paratrooper with a shoulder injury, bulging discs and a degenerative arthritis condition in his back. Nelson also suffers from migraine headaches, post-traumatic stress disorder and a possible brain injury.

The VA has classified Nelson as 90 percent disabled and sends him a check every month. Despite his high disability rating, he works as an event coordinator for a nonprofit golf organization. He takes eight Vicodin pills a day, but they no longer dull his aches.

“I would give anything to be pain-free right now and to not get that check every month and just to live a normal life,” he said.

His injuries stem from a 2005 explosion in Afghanistan during an attack on a landing strip in a remote village. Two other soldiers died. His body is still riddled with shrapnel.

Nelson is just one of thousands of Minnesota veterans living with chronic pain from a group of service-related conditions known as musculoskeletal disorders. Brought on by sudden injuries or developing over time, the conditions affect bones, muscles, joints, ligaments, nerves and tendons.

Not all those cases are caused by injuries as dramatic as Nelson’s. Doctors and soldiers say the increase in such disorders likely is directly related to the heavy equipment soldiers carry and the body armor they wear to stay safe.

According to the Army, the combat load for a rifleman weighs as much as 170 pounds. In 2001, the Army chief of staff recommended that by 2010 soldiers lug no more than 50 pounds. The Army is still struggling to meet that goal.

Dr. Paul Huddleston, an orthopedic surgeon at the Mayo Clinic and colonel in the Army Reserve Medical Corps who deployed three times to Iraq and once to Afghanistan, said he believes National Guard and Reserve soldiers may be at even greater risk for injury because they tend to be older than their active-duty counterparts.

“There is an old saying in the Army that they used to treat the soldiers like Christmas trees and see how much stuff they could hang on them,” he said.