Kinematics of the toe touching test: an investigation using motion analysis

We describe a technique for measuring dynamic motion at the low back along with the major lower limb joints during the toe touching maneuver. This type of motion analysis was carried out on eight normal volunteers. Flexion during the toe touching maneuver involves not only low back and hip movement but also ankle plantar flexion and a varying degree of knee movement. The low back and ankle movements were highly correlated within each subject to an extent that suggests a functional connection between the lower limb and low back movements. The significance of our work is two-fold. First, we emphasize that the toe touching test represents a combined movement of the low back, the hips, the knees, and the ankles and it is reasonable to suggest that abnormalities of these joints may affect the clinical relevance of the test as an indicator of back movement. Second, we point out that the guidelines of the American Medical Association in using the test to determine hip movement are incorrect as they do not take into account the effect of knee and ankle movements on the estimation of hip movement.