As the military prepares to allow female troops in ground combat units, studies show the Department of Veterans Affairs can expect more female veterans will suffer from the kinds of injuries that go with being a ground-pounder.
No one can yet say what that means in treatment program costs or disability compensation increases, but Army and VA studies show that women will be at greater risk for musculoskeletal injuries.
Advocates for women serving in direct combat units say the problem may be overcome without lowering standards by improved training and fitness, while critics say nothing is going to change the fact that women are not built to be in the infantry.
For its part, the VA says it has to be ready for a possible rise in the number of female troops with bone, joint and ligament injuries.
"I don't think there is a way now to say exactly what the experience will be, but I expect as more and more women go into these physically demanding roles, we may see an increase in [these] injuries," said Dr. Sally Haskell, VA deputy chief consultant for women's health services and director of comprehensive women's health.
She said the VA already has begun ramping up services for women, including establishing a group of physicians that are its experts in women's health care. This program specifically includes sessions in musculoskeletal health. Also, she said, "we're just beginning to assess our capacity to care for women's specialty needs in the areas of rheumatology and orthopedics."
Women generally, in and out of the military, incur musculoskeletal injuries at rates at least somewhat higher than men, Haskell said.
Dr. David Cifu, the VA's national director for physical medicine and rehabilitation, said last year that women carrying the same loads as their male counterparts in the infantry risk more of these kinds of injuries "given the ratio of their size and strength to the packs." A typical infantry soldier carries a load of about 80 pounds.
It is not merely about body strength, according to a 2011 Army paper, it is that "the combination of anatomy and physiology appears to predispose women to a higher risk of pelvic stress fractures and knee damage."
The paper, "Musculoskeletal Injuries in Military Women," cites multiple Army, VA and Navy data, including a Navy study that found 1 in 367 female recruits were diagnosed with a pelvic stress fracture, versus one in 40,000 male recruits. At the same time, the Army noted that its experience with these kinds of injuries is nearly three times that of the Navy.
"Acute and chronic musculoskeletal problems associated with injuries are consistently the leading causes of outpatient visits and hospitalizations in the Army," the report stated.
The Army also cited a May 2013 Technical Bulletin, "Prevention and Control of Musculoskeletal Injuries," that women are more likely to be disabled than men and are about 67 percent more likely than a male soldier to be discharged for a musculoskeletal disorder. Such discharges have been as high as 140 per 10,000 female soldiers per year, the study said. For men, the number has been about 80 per 10,000 soldiers, according to the study.
Disability costs, the Army said, "are staggering." Even before the wars in Afghanistan and Iraq, the VA was already paying roughly 25 percent of its annual $21 billion compensation budget to vets with musculoskeletal injuries.
Up to that point, musculoskeletal disorders already were the leading cause of Army disability cases, constituting 73 percent of the total disability cases for all causes from 1997-2002.
Retired Rear Adm. Hugh Scott, a Navy medical officer, said musculoskeletal injuries "will continue to occur, certainly more frequently among females, if they're expected to perform all the required tasks that go with [duty in] combat units."
"I know it's not politically correct to say this, but men and women are not the same -- there are physical and physiological differences that exist," said Scott, who is on the board of advisers of the Center for Military Readiness. "As long as women are going to have babies, their pelvis is designed as a birth canal, it's designed for that to happen. It's not conducive to heavy load-bearing."
Problems with musculoskeletal injuries among women won't go away, he said, but will worsen as more of them train for and enter ground combat units.
Scott predicts that increasing incidents of bone, joint and ligament injuries will be reflected in the future at the VA, with more disabled female veterans and increasing costs for disability compensation.
"I would expect that ... based on what they've already experienced with regard to women veterans," he said.
Though it does not break down disabilities by type between men and women, a February 2013 VA profile of female veterans stated that a higher percentage of female vets than male vets had a service-connected disability in 2011 -- 19 percent versus 16 percent.
Scott said he believes the numbers of disabled female veterans will only increase with more of them going into direct ground combat units.
"If there is anything the VA can do, it is to look at research in this area, to see if there is a better way to treat these individuals," he said.
Greg Jacob, a former enlisted and officer Marine who is now policy director for Service Women's Action Network, said the Corps looked at the problem of musculoskeletal injuries in 2003.
He said such injuries prevented more than half the women recruits from making it through training.
But the solution is not to keep certain specialties or units closed to women, he said, but to make them better prepared and fit to succeed without sacrificing standards. At Parris Island, S.C., one of the Corps' two boot camps, officials brought in a fitness trainer who had worked with the Carolina Panthers football team to help improve training and avoid injuries, he said,
After about a year, he said, "we started to see these injuries go down."
That's the answer for the Corps and for the Army, he believes.
"It's not man versus women, but an issue that the military has to address," he said. "Demands of combat are not going to change. The rigors of combat are not going to change. But we have to change the way we prepare our people."