Patients with chronic low back pain often have low levels of activity. Most say pain keeps them from doing activities. But researchers have found that patients’ pain isn’t always linked to their physical performance. What other factors might get in the way of activity? Does emotional well-being have anything to do with it?
These authors tested 75 patients with chronic low back pain using a treadmill. The patients averaged 40 years old. They’d had back pain for about three years. The patients were told to walk on the treadmill as long as they could at three different speeds and inclines. Patients reported their amount of pain on a scale from zero to ten before and after the treadmill test. Patients’ walking times and physical fitness were recorded. Patients also filled out a mental health questionnaire.
Pain went up after walking. Patients with more pain walked for shorter periods of time. Older patients also walked less. Patients’ gender and history with back pain didn’t make any difference in how long they walked.
About half of the patients were said to have low mental health. This was determined when patients’ responses on the questionnaire showed depression, anxiety, loss of self-control, and lack of well-being. Compared to the other patients, these patients were more likely to be on disability and have lower incomes. However, patients with low mental health reported about the same amount of pain before and after the treadmill test as the “mentally healthy” patients. Patients with low mental health were equally fit as the other patients and walked about the same amount of time.
What stopped patients from walking? Roughly half stopped because of pain. Not surprisingly, patients who stopped because of pain had higher pain scores than those who stopped because of fatigue. Patients who stopped because of pain walked fewer minutes, though they were equally fit as the patients who stopped because they got tired.
Patients who stopped walking because of pain were more likely to have low mental health scores. However, mental health wasn’t related to how long patients walked on the treadmill; pain was. This suggests that poor mental health is a result (not a cause) of the pain patients experience with physical activity.
Health professionals have different theories about how chronic pain affects mood and behavior. One theory is that mood determines behavior. (You don’t feel good emotionally, so you don’t perform well physically.) The other theory is that pain gets in the way of physical performance, which then affects mood. (You don’t feel good or do well physically, which makes you feel bad emotionally.) This study supports the second theory more than the first. In terms of physical performance, patients’ reason for stopping on the treadmill (pain) was more important than their mental health.
Pain is a common reason that patients drop out of treatment programs involving physical activity. The authors are investigating whether patients who have relatively more pain in physical activity are the ones who drop out of treatment, and whether their physical performance improves with treatment.