TUESDAY, April 7, 2015 (HealthDay News) -- Physical therapy may be just as good as surgery for older adults with a type of chronic lower back pain, new research suggests.

Standard treatments for lumbar spinal stenosis -- a painful, often disabling narrowing of the spinal canal -- are an operation known as surgical decompression or physical therapy.

But physical therapy is much less invasive and less risky than surgery.

"Adverse events from surgery range from 15 to 20 percent, with half of those being serious or life-threatening," said study author Anthony Delitto.

"The risks of physical therapy are considerably less, and one would be hard-pressed to consider any of the risks serious," said Delitto, a professor of physical therapy and associate dean of research with the school of health and rehabilitation sciences at the University of Pittsburgh.

Results of the study, funded by the U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases, appear in the April 7 issue of the Annals of Internal Medicine.

According to the American Academy of Orthopaedic Surgeons, spinal degeneration and wear and tear (often due to chronic arthritis) can narrow the space surrounding the spinal cord, drying out spinal discs and compressing the cord and its nerve roots. This is called lumbar spinal stenosis.

The condition, which causes pain, numbness and/or weakness across the lower back, rear and legs, mostly appears in patients aged 60 and older.

Non-surgical treatments, such as anti-inflammatory medicine and physical therapy, do not reverse spinal narrowing, but can provide a notable degree of pain relief and restored mobility, experts say.

Surgical options include spinal decompression (or laminectomy), which involves removal of the bones, bone spurs and ligaments that exert pressure on spinal nerves. Spinal fusion, sometimes coupled with decompression, is another option. Delitto noted that both surgery and physical therapy are covered by Medicare, meaning that while surgery looks far more expensive on paper, physical therapy patients sometimes face slightly higher actual out-of-pocket costs.

To assess the comparative benefits of each treatment, investigators focused on nearly 170 patients with lumbar spinal stenosis who sought care in western Pennsylvania. On average, participants were in their late 60s, and none had undergone prior surgery for the condition. All demonstrated similar mobility impairment, and on a pain scale of 1 to 10 all were rated 7 prior to treatment.