Regional lumbar sagittal mobility and back trouble

Abstract

It is a commonly held view in the fields of biomechanics and clinical medicine that a relationship exists between abnormal lumbar sagittal mobility and low back trouble (LBT). There is general belief that sagittal mobility is reduced in patients suffering from LBT, and clinicians traditionally consider the range of mobility when assessing such patients. However, the evidence available from research studies is often difficult to interpret and reference/normal values are not yet agreed. These problems are in part due to the wide range of measurement techniques available (reviewed by Pearcy1), and to doubts about their accuracy and reliability. The most frequently used clinical technique, for instance, employs a tape measure2 but this has been shown by Reynolds3 to be less reliable than inclinometric measurements. In their study of 237 clinically and radiologically normal subjects, Moll & Wright2 concluded that lumbar sagittal mobility was influenced by age and sex (reduced from age 25 years and reduced in females). Their method of measurement of flexion includes in its values the movement required to abolish the lumbar lordosis and may thus be considered to overestimate true flexion (the converse being the case for extension), which makes comparison of their reference values with those obtained by, say, inclinometers particularly difficult.