Turn this way, bend over, walk across the room. Doctors put patients with back problems through all sorts of physical tests during an exam. The idea is to see which movements and positions hurt and how much the back problems interfere with the activities of daily life. But how well do the physical tests really reflect how patients function at home or on the job?
In this study, researchers assessed the functional mobility of patients with lumbar spinal stenosis (LSS) and people with healthy backs. All of the subjects were elderly. The researchers used three tests of functional mobility. The first involved walking on a treadmill at gradually increasing difficulty until reaching 70% of maximum heart rate or until feeling pain. The other two tests timed subjects as they rose from a chair without using their arms, and as they walked for 20 meters carrying small amounts of weight. Subjects repeated these last two tests three times.
Part of the reason that the researchers had subjects repeat the tests was to see if they got similar results all three times. They did, which suggests that these tests are reliable indicators of back problems. The researchers also tried to design these tests to mimic the physical demands of everyday activities. Carrying the weights, for example, is something like carrying groceries from the car to the house.
The researchers were also interested in comparing the results of the healthy and LSS groups. As expected, the healthy group showed better functional mobility than the group with LSS. The differences were especially significant in the treadmill test. Almost half of the group with LSS couldn’t finish the test because of pain, which pull the scores in the LSS group down. At first, it might be assumed that patients with the worst back problems were more likely to have problems with the treadmill. But patients with moderate and severe LSS also had problems completing the treadmill test. The authors suggest that the real reason for problems on the treadmill might be that patients with LSS tend to limit their exercise. Over time, this causes them to become out of shape.
The authors feel these types of tests show evidence of being a valid way to check how elderly patients with LSS are getting along with their daily activities. This suggests the tests could be done again at a later date to see if treatments that are being used are actually helping.