Layli Nottingham, 56, of Palmer, Alaska, said whenever she experienced neck pain she would turn to her chiropractor.
That is, until 1994, when a visit to her chiropractor to undergo a routine technique called spinal manipulation only made her pain worse.
"The pain was so excruciating and it was hitting the nerve that went down the right arm," said Nottingham. "I really had no idea what was wrong with me."
Spinal manipulation, a procedure that uses a flow of movement and points along the vertebrae to restore joint motion and realign the spine, is one of the most common treatments for neck pain. Previous studies suggest between 6 percent to 12 percent of Americans undergo spinal manipulation every year.
But the safety and efficacy of the technique has long been debated by medical experts.
Some evidence suggests that spinal manipulation, which is most often used by chiropractors, can offer some benefit to people who have back pain and some musculoskeletal disorders.
The technique varies in level and intensity, depending on the severity of the ailment, said Keith Overland, a chiropractor and president of the American Chiropractic Association.
However, some medical experts question whether spinal manipulation is a safe and effective technique for patients with neck pain.
Two reviews of the evidence by researchers published Thursday in the British Medical Journal add one more weight on the each side for and against spinal manipulation.
In the first review, the authors conclude the technique is "unnecessary and inadvisable." The review cites studies that have suggested an association between spinal manipulation and more intense injuries, including tearing of the artery, and even stroke.
The studies "provide consistent evidence of an association between neurovascular injury and recent exposure to cervical manipulation," according to Neil O'Connell, a lecturer at the center for research in rehabilitation at Brunel University in Uxbridge and his colleagues wrote.
According to Overland, the most common side effect from manipulation is soreness, adding that other more serious side effects are extremely rare.
"Yes, people had strokes, but they were most likely going to suffer the stroke regardless of the provider they chose," said Overland. "It's incumbent upon the doctor to do a proper thorough examination before giving a treatment."
The second study review suggests there are benefits to the technique, especially when used together with other pain relieving methods, such as exercise.
"We say no to abandoning manipulation and yes to more rigorous research on the benefits and harms of this and other common interventions for neck pain," David Cassidy, a professor in the department of epidemiology at the Dalla Lana School of Public Health at the University of Toronto, and his colleagues wrote.
Nottingham had a herniated disc, but at the time, she and her chiropractor didn't know it. Three months after her visit with the chiropractor, an orthopedic surgeon and neurosurgeon diagnosed her condition and recommended physical therapy. Nottingham said if she'd known how serious her condition was, she would've sought help from an orthopedic specialist sooner.
"There is a time and place and certain conditions when chiropractors would be helpful," said Nottigham, adding that she didn't think her chiropractor caused the problem. "I have not seen one since."
According to Dr. Cain Dimon, physician director of the center for pain medicine at William Beaumont Hospitals in Royal Oak, Mich., spinal manipulation may be appropriate only after patients receive a full physical exam to detect the problem and undergo other types of treatments to relieve the pain first.
"I certainly don't dismiss chiropractic manipulation," said Dimon. "It can certainly help in some cases lower pain."
Overland said it's unlikely that a chiropractor would perform a spinal manipulation without first knowing the exact cause of pain.
"If a person has a herniated disc, this would've been diagnosed, said Overland. "Usually chiropractors do a full orthopedic and neurologic examination."
In fact, there are some cases where manipulation may exacerbate the pain, said Dimon.
For some experts, the problem with spinal manipulation is that it is has become an overpromising treatment for conditions outside the physiological realm of the technique. For years, chiropractors have faced criticism for claiming their practices work to cure a wide variety of ailments, including asthma and cancer.
"It's hard for me to understand physiologically how that would work," said Dimon, who cautioned against undergoing treatments without a physician recommendation.
According to Overland, the lingering controversy over spinal manipulation has less to do with the data concerning its safety or efficacy, and more to do with the resounding consensus by many conventional medical doctors spanning decades that suggests chiropractors are not an equal part of the medical community.
"There's still a lot of residual bias against the profession," said Overland. "Yes, there's risk of every medical procedure, but we need to move away from health in a bottle."
The medical community should place a larger emphasis on understanding chiropractic techniques, he said.
"What's lacking is really good research is how spinal manipulation is helping other types of chronic conditions," said Overland.