But alarmingly high suicide rates among veterans, as well as domestic violence, substance abuse and unemployment, suggested to some military doctors, combat commanders and researchers that conventional treatments aren’t always enough.

Now, one proven, effective treatment is gaining wide acceptance within hard-core military circles: yoga.

Once dismissed as mere acrobatics with incense, yoga has been found to help ease the pain, stiffness, anger, night terrors, memory lapses, anxiety and depression that often afflict wounded warriors.

“It’s cleansing — I really feel refreshed,” Marine Sgt. Senio Martz said after finishing a recent yoga session.

A stocky 27-year-old, Martz was leading his nine-man squad on a foot patrol through the lush poppy fields and rock outcroppings of the Kajaki district of southern Afghanistan 20 months ago when a roadside bomb knocked him unconscious and killed or wounded the Marines under his command. The blast put an end to his plans for a career in the Marine Corps. It also left him hyper-vigilant, a symptom of post-traumatic stress disorder, and carrying the joint burdens of guilt and shame: As a squad leader, it had been his responsibility to bring his nine Marines home safe.

“It’s a feeling of regret — failure — that really affects me now,” he said. “I didn’t see the signs that could have alerted me to warn them to get away.” He stared at the floor and then looked up with a tight smile. “I go on living where their lives have ended. I can’t help them now.”

Yoga gives him relief from the acute anxiety that forces him to listen to and sight-sweep everything around him, constantly checking the doors and windows, always on alert, poised for danger, with no break. It is hard for him to let go.

“I gotta push myself to try some of these techniques,” he admitted. “But last night after yoga, I had a good sleep. That’s a place I haven’t been in a long, long time.”

Martz’s experience is backed up by reams of scientific studies, including research funded by the Pentagon and the Department of Veterans Affairs. Researchers have demonstrated that trauma-sensitive yoga, which focuses on stretching, breathing techniques and meditation, can help patients regain their inner balance, calming that part of the brain that has become hyper-aroused under severe stress.

Trauma or prolonged stress can cause a malfunction of the parasympathetic nervous system, researchers say. That’s the part of the brain which enables the body to relax, easing pain and even helping unblock digestive systems — often a problem for wounded troops who get high doses of medication and not enough exercise.

In war zones, researchers have found, this parasympathetic nervous system often becomes “frozen” as the body gears up for danger by injecting adrenaline into the bloodstream, causing rapid breathing and pulse and hyper-vigilance — the “fight or flight” response.

That’s good and necessary self-preservation in times of peril that helps keep troops alert and alive. Back home, however, that hyper-vigilance is out of place and can cause insomnia, anxiety and outbursts of anger. Returning warriors with PTSD become dependent on drugs or alcohol “because they have no other way to calm themselves down,” said Dr. Bessel van der Kolk, a clinician and researcher who has studied PTSD since the 1970s.

Not all yoga helps. Some forms of yoga are used by special forces, for instance, to build muscle power and flexibility. But yoga teachers working with wounded troops have developed trauma-sensitive forms of yoga, including a technique called iRest. This adaptation uses meditation techniques in a soft and secure setting to reactivate the parasympathetic nervous system by drawing the patient’s attention and consciousness inward, rather than focusing on stress and the terrors that dwell outside, said yoga teacher Robin Carnes.

For instance, Carnes has learned that when she is giving a class to troops with hyper-vigilance, like Martz, she should first open all the closet doors and drawers, so that her patients don’t spend all their time fretting about what might be inside.

In 2006 Carnes, a veteran yoga practitioner and teacher, began working with wounded troops at Walter Reed National Military Medical Center, now located outside Washington, D.C. There, she led a Pentagon-funded program to develop trauma-sensitive yoga, and pioneered the techniques now called iRest. She later established an organization called Warriors at Ease to train and certify teachers to use the techniques with the military.

Drawing from traditional yoga, iRest teaches patients to firmly plant their feet and activate their leg muscles in poses that drain energy and tension from the neck and shoulders, where they naturally gather, causing headaches and neck pain.

“The goal here is to move tension away from where it builds up when you are stressed, and focus it on the ground so you feel more balanced and connected,” Carnes said.

When she started at Walter Reed, she said, she was working with eight wounded troops with physical and mental health injuries. Some hadn’t slept for more than two hours at a time, for years, she said. “They were immediately like, ‘I can’t do this, it won’t work, you have no idea what’s going on in my brain.’ I’d say, ‘Just try it, it’s helped others.’ And probably because they were desperate — nothing else had worked, including drugs — they did try it. And I saw, sometimes within the first day, they started to relax. Snoring! They’d tell me, ‘I don’t know what happened, but I feel better.'”

One of her patients was struggling with outbursts of violent anger, a common effect of PTSD, and had gotten into raging arguments with his wife. Several weeks into regular yoga classes, he went home one day “and his wife lit into him and he could feel a confrontation coming on,” Carnes said. “He told me that he’d taken a deep breath and told his wife he was going upstairs to meditate. And that was the first time he’d been able to do that.”

Practices like iRest and other forms of yoga are so clearly effective that now they are taught and used at dozens of military bases and medical centers — even at Little Creek Naval Amphibious Base in Norfolk, Va., home of the Navy SEALs, the branch of commandos who killed Osama bin Laden.

“I knew anecdotally that yoga helped — and now we have clinical proof of its impact on the brain, and on the heart,” said retired Rear Adm. Tom Steffens, a decorated Navy SEAL commander and yoga convert. Within the military services and the Department of Veterans Affairs, he said, “I see it growing all the time.”

Steffens, an energetic man with a booming voice, first tried yoga to deal with his torn bicep, an injury that surgery and medication hadn’t helped. He quickly became a convert, practicing yoga daily. Visiting with wounded SEALs a decade ago, he noticed that “the type of rehab they were doing was wonderful, but there was no inward focus on themselves — it was all about power as opposed to stretching and breathing.”

Before long, Steffens had helped start a foundation, Exalted Warrior, that holds yoga classes for wounded troops and their families at the Portsmouth Naval Hospital in Virginia, the James A. Haley VA Medical Center in Tampa, Fla., and elsewhere.

The military’s embrace of yoga shouldn’t be a surprise. After all, yoga — a Sanskrit word meaning to “join” or “unite” — dates back to 3,000 B.C., and its basic techniques were used in the 12th century when Samurai warriors prepared for battle with Zen meditation. Still, some old-timers are shocked to find combat Marines at Camp Lejeune, N.C. and amputees at James A. Haley VA Medical Center practicing theirDownward Dog and deep breathing techniques.

One early skeptic: Thomas S. Jones, a wiry retired Marine major general who likes to mask his love for Marines with a staccato parade-ground bark and a jut-jawed, prove-it approach to life.

Some years ago Jones started inviting wounded Marines to an intense, six-day retreat at a camp in the mountains of Pennsylvania to help them figure out what to do with the rest of their lives, to set goals and start working toward them. He quickly found that the Marines, struggling with physical wounds and PTSD, had trouble focusing. Someone mentioned that yoga might help. “Well, we’ve tried some ideas that didn’t work out and we threw them away,” Jones said dismissively, “but we’ll try it.”

And? “It has helped,” Jones told The Huffington Post in a slightly disbelieving voice. Yoga has since become a centerpiece of the retreat, called Semper Fi Odyssey. “This whole idea of relaxation, there’s a lotta guys who can’t do hardly anything physical, can still do yoga. And there’s a lot of value in meditation.”

The results, Jones and others have discovered, are indisputable.

A study published earlier this year of 70 active-duty U.S. troops, then-based at Forward Operating Base Warrior, in Kirkuk, Iraq, found that daily yoga helped relieve anxiety, reduced irritability and improved sleep — even amid daily “gunfire and helicopter sounds.”

Progressive relaxation, calming breathing and relaxation techniques “reduce physical, emotional, mental and even subconscious tension that characterizes PTSD,” according to retired Air Force Maj. Nisha N. Money, a physician who recently served as chief of fitness policy for the Air Force.

“Guys with trauma — their center is out there,” said Annie Okerlin, flinging her arm outward. She’s a yoga expert who works with wounded warriors, families and staff therapists at the VA hospital in Tampa, Walter Reed and elsewhere. “What we do is gently and sweetly bring them back to their center, here,” she said, touching her chest.

Much of her work is with amputees. “I always tell the guys, ‘Your brain still thinks your leg is there, so we are going to speak to your brain as if your limb IS still there,”’ she said. “I tell them to flex the foot — spread your toes! — and the brain goes, ahhh, that feels good, I’m stretching — even though that limb is no longer there. It settles the brain down, because it’s doing its job, the blood flow increases, guys can feel their body again, the trauma fades. It’s beautiful!”

Working at Walter Reed, she once came across a double, above-the-knee amputee, who had been wounded by an IED. He was huddled in his hospital bed, his mother perched beside him on the edge of a chair, and for weeks he had refused to move, even for his physical therapy sessions. He admitted he was ashamed to be seen with his stumps twitching. Okerlin sat with him, leading him through some gentle breathing exercises. She could see him relax, and after a few minutes he fell asleep.

The next day he showed up for his physical therapy appointment to begin the healing.

With partially-paralyzed patients, Okerlin often has them lie on their back, put their hands on their rib cage and feel their breathing. One patient told her he was amazed to find he could feel a rush of energy toward his legs even though he still had no sensation in his legs.

Okerlin recently spent several days at a Semper Fi Odyssey retreat, teaching yoga and iRest to Marines with physical wounds, PTSD or traumatic brain injury. She has a warm and engaging style and works to establish a non-threatening environment in her sessions. “People who’ve been traumatized have lost their ability to feel secure,” she said.

As the wounded Marines settled onto floor mats, she told them, “You can close your eyes if that feels comfortable, but I will have my eyes open all the time watching,” emphasizing that they are safe and can relax. “There’s no wrong way to do this,” she said. “Are there any head injuries here?” she asked, and a wiseguy in the class called out, “We’re ALL head injuries!” to general chuckles.

At one point she had them on their backs, knees drawn up and held by their arms, a posture she tells them “massages the descending colon.” “This will help ensure you have that morning constitutional,” she told them cheerfully as they gently rocked back and forth.

Soon she had them focusing all their attention on their breathing, urging them to feel how each inward and outward breath lightly traces their spine. “Now I’m going to turn the lights out,” she said softly, “in three, two … one. If you fall asleep, that’s fine. If you’re snoring too loudly, I will come by and touch you on your right shoulder.”

On the mat next to Sgt. Martz were two Marines. One was Billy Wright, 49, who did two combat tours in Lebanon in 1983 and was later paralyzed from the chest down in a car wreck. He uses yoga breathing exercises to loosen up his muscles and joints that stiffen from long periods in his wheelchair. “Even lying on my back I can feel my hips flex,” he said. “Sitting in the chair, they get real tight and this loosens them up.”

The other was 24-year-old Joshua Boyd from Dry Fork, Va., a Marine lance corporal who did two combat tours in Iraq and came home wounded, with PTSD and mild TBI. He lost a good friend, a fellow Marine, who was killed by an IED. “They had stuck it inside a culvert,” Boyd said. “I had just gotten to Iraq and didn’t have IED training and I didn’t know what to look for. I didn’t look where I should have. It was my fault.”

After the blast, he said, he and his platoon collected the body parts.

At night, Boyd often jackknifes awake, yelling and sweating, dreaming of an intense firefight he experienced in Iraq in 2007. During this recurring dream, his wife is there in the middle of the battle and his buddies have abandoned them both while insurgents are closing in on them. He can feel them sense his weakness.

“I do have trouble sleeping,” he said sheepishly. During the long nights, he is often either deep in his nightmare, or terrified he is about to have it again.

But yoga has helped change the way he sleeps and dreams. “Yesterday I did the iRest session. I fell asleep,” he said. “When I got done, I felt so much more energized. I haven’t felt like that for years.”