Abstract:
The intervertebral foramina, aptly described by Hadley (1949) as being at the
crossroads between the peripheral nervous system and the movable skeletal support,
transmit the spinal nerves, spinal arteries and veins, the recurrent meningeal nerves and
lymphatics. Reports of studies of the aetiology of low back pain suggest that pressure
on the emerging spinal nerve or other contents of the foramen in the lumbar region
could be an important source of low back pain and sciatica. Adequacy of space within
the foramen with respect to the foraminal contents is therefore of serious import. The
intervertebral foramen differs from other osseous foramina in having as part of its
boundaries two movable joints, namely the intervertebral joint anteriorly and the joint
between the articular processes (zygapophyseal joint) posteriorly. Normal spinal
movements therefore, cause changes in the size of the foramen. Evidence brought by
Hadley (1949), Payne & Spillane (1957), Sunderland (1980), Rothman & Simeone
(1982) and Crelin (1982) suggests that the foramen undergoes narrowing or widening
depending on the movement performed.