Measuring Low Back Pain Disability

The number of people who suffer lower back pain (LBP) is staggering. In fact, it is one of the most common causes of disability and missed work days. These costs add up for individuals, employers, and society. Even with all the advanced technology now available, the medical world is still working hard to be able to understand LBP and the disability it causes. In more than 80% of LBP cases, doctors are unable to find any particular physical cause.

Getting an accurate measurement of the disability caused by LBP is not an easy task. Canadian researchers recently did tests to see whether spine movement and speed could be used to measure disability from LBP. Called kinematics, these analyses are part of the study of biomechanics. Spine kinematic tests study the motion of the spine in movements such as bending over to touch your toes. Many doctors do these tests to get an idea about disability status, but no one really knows how accurately these test results measure disability.

The researchers tested spine kinematics on 175 patients who missed four weeks of work because of LBP. Patients also filled out a survey with questions about their back problem. The kinematic scores were compared to the work status of the patients and to their reports about pain, sleep, and ability to do self-care and daily activities.

The results of the kinematic tests didn't relate very well to either the questionnaire or the patients' work status. Remarkably, the kinematic results didn't always seem to improve, even when patients started to report feeling better and as they went back to work. The researchers conclude that spine kinematics, while useful in other ways, are not helpful in determining the level of disability in patients with LBP.