AbstractPerhaps the most important consequence in the provision of a traction force to the human spinal column is the subsequent foraminal distraction which occurs. A lateral x-ray was taken of the left lumbar neuroforamen in 10 subjects. The average foraminal opening was over 4 mm at L3, L4, and L5. It is possible that even greater opening could have been achieved if towel rolls had been individually fitted as is done in a clinical setting. This study confirms the merit of positional distraction as a means to open the lumbar neuroforamen.