So that hurt, didn't it? Bending down to pick up this newspaper -- it hurt your lower back, right?

Hey, you've got company: Millions of Americans suffer from lower back pain. And the back-specific exercises many people do to relieve their agony (often following a medical or fitness professional's advice) tend to make it worse, a new study shows.

Ah, but good news: The same study showed that general physical activity, like walking, reduces back pain -- acute, chronic and disability-causing pain. The research also showed that exercise reduces psychological distress. (Yet more evidence to support our shameless promotion of exercise, conducted wisely, as a cure for everything from acne to poor annual reviews, not to mention that nasty bruxism your dentist keeps telling you about.)

The study -- involving 681 men and women, aged 34 to 69, who sought treatment for low-back pain -- was published in the October issue of the peer-reviewed American Journal of Public Health.

All data were self-reported, including pain (on a zero-to-10 scale, with 10 representing unbearable pain), psychological distress, frequency and amount of physical activity, and frequency of low-back exercises. The average pain score was seven; 77 percent of the group said they had at least one day of restricted activity in the prior month due to back pain, and about 47 percent reported having had back pain for more than a year. (Those who find this description distressingly familiar, raise your hand -- oh, wait, be careful.)

Participants filled out questionnaires six weeks after enrolling in the study and again at six, 12 and 18 months.

Researchers converted exercise data for each participant into metabolic equivalent task (MET) values. Those who exerted at least 10.5 METs per week -- about the equivalent of three hours of brisk walking or similar activity -- showed the greatest reductions in back pain and psychological distress.

Participants who exerted 26 or more METs per week on exercise of any sort were less than half as likely as non-exercisers to report disability due to low back pain.

But back exercises increased the odds of subsequent low back pain and disability by 64 percent and 44 percent, respectively. And among the participants who did lower-back exercises, those who did them the least -- less often than one day per week -- reported the lowest pain levels.

Maddeningly, researchers did not collect data on which back exercises each person performed, nor did they determine why the exercises might worsen back pain. These failings reduce the value of the findings. Poor form and the wrong exercises may explain the negative results, they said.

The findings are not surprising, says William O. Roberts, an associate professor at the University of Minnesota Medical School and a past president of the American College of Sports Medicine.

"Get people moving and it helps [address] their back pain," Roberts said.

"I have moved away from back stretching and strengthening to doing more whole-core strengthening. You want to build up the supporting musculature" for the back, he said. The core includes the entire torso, including muscles and connecting tissues in the abdominal area, the sides, the back and the hips.

Roberts recommends daily walking and such core exercises as "bridging": While lying on your back, slide your feet toward your butt and lift your butt and lower back off the floor, so you're supported by your shoulders and feet. He also suggests modified crunches, where you raise only your shoulders off the ground. Full sit-ups can exacerbate back problems.

No online chat today; back next week. Meantime, do you have stories about your own back pain? E-mail us at

-- John Briley