Lower Back pain


ligamentous- muscular support

lower Back pain syndrome

ligamentous- muscular support

FIGURE 25. Sensorimotor aspect of
nerve rool Within the intervertebral
foramen the motor roots are smaller
than the sensory and are inferior and
posterior near the disc

terior (motor) root. Thes" remain separate until encountering the ganglion
of the sensory root, at which point they merge into a single
funiculus. In their further descent and outward migration the motor
(nerve roots are concentrated anterioinferiorly in the funiculus (Fig. 25
The nerve roots and their dural sleeves are attached loosely to the
foramina and are permitted to move. The nerve axons have plasticity
but the dura has no elasticity. Traction distally or dorsally pulls the
entire nerve fiber-dura complex in either direction. The nerve roots
intrinsically elongate, whereas the dura increases in tension. This will
be discussed further in the chapter on disc herniation
Within the foramen the nerve and its sheath occupies 35 to 50 percent
of the space. The remainder of the foramen is filled with loose areolar
connective tissue, adipose tissue, arteries, veins, lymphatics, and the
(recurrent nerve of Luschka (Fig. 26
Upon emergence from the foramen, the nerves divide into their
anterior and posterior primary division, sending immediately a branch
to the facet joints (Fig. 27). Within the foramen only the dura innervated
by the recurrent nerve of Luschka is apparently pain-sensitive. The
posterior longitudinal ligament also innervated by this nerve is likewise
We have ascertained which tissues within the functional unit are
capable of eliCiting pain, and we have depicted the static erect spine by
combining and superimposing the functional units. Now we must make
our upright person move and, in moving, the normal must be established
so that deviations capable of causing pain can be understood


Consideration of the periarticular tissues and muscular influence on
the kinetic spine involves once again a discussion of the static spine

FIGURE 26. Dura accompanying nerve root through intervertebral foramen with its
innervation by the recurrent meningeal nerve. 1 and 2 proceed to the anterior dural
sheath, illustrating the sensitivity of that portion of the dura. The posterior dural sheath
with no innervation is insensitive. 3. Innervation which is cnpabJe of pain supplies the
posterolongitudinal ligament

.because a balanced erect static spine requires minimal muscular effort
Physiologic erect balance is essentially a ligamentous function relieved
by intermittent small muscular contractions that are triggered by
proprioceptive reflexes of the joints and ligaments. The muscles of an
erect but relaxed man are electromyographically silent except for those
in the gastrocnemius groups. The calf muscles which balance the leg at
the ankle joint are the only continually active muscular group affecting
Ligamentous support is effortless and thus not fatiguing. Excessive
or prolonged ligamentous stress ;s relieved by muscular contraction
and, as muscular effort is fatiguing, is held to a minimum for economy of

energy expenditure. Good posture requires balance between

FIGURE 27. Division o f nerve roots. Upon emergence from the foramen, the roots
divide into the anterior primary division and the posterior primary division. A small
articular branch is sensory to the facets

ligamentous support and minimal, yet adequate, muscle tone. Improper
posture or prolonged stress from awkward positions causes
protracted ligamentous strain resulting in discomfort. Strain may arise
.because of muscular fatigue which no longer affords ligamentous relief
.For proper posture, the static spine is dependent on the pelvic angle
The pelvis is held in ligamentous balance by the anterior hip joint and
the "Y" ligament. This "Y" ligament, the iliopectineal ligament, is a
fibrous reinforcement of the anterior portion of the hip joint that prevents
hyperextension of the hip. In erect stance, man "leans forward on
this ligament."
The knee joint can similarly be "locked" in extension when it relies
on the posterior popliteal tissue that prevents overextending the
knees. This position eliminates the need for any muscular effort on the
part of the quadriceps femoris. The lumbar spine can "lean" on the
,anterior-longitudinal ligament and the abdominal wall. The ankle joint
however, cannot be "locked" in any position so that muscular effort is
required constantly.
The pelvis is further supported by the tensor fascia latae. These
fascial bands mechanically assist the "Y" ligaments as well as limit
lateral shift of the pelvis. Their course from the iliac crests downward
and backward to insert at the iliotibial band at the knee lends itself well
(to reinforcing the "Y" ligament and helps lock the knee (Fig. 28
The pelvic angle is the key to ligamentous posture. Rotation of the
pelvis will initiate a total unlocking of all the balancing joints and
necessitate muscular effort

FICURE 28. Static spine support. The relaxed person leans on his ligaments: the
iHofemorai ligament, ("yo, ligament of Bigelow), the anterior longitudinal ligament, and
the posterior knee ligaments. The ankle cannot be "locked," but by leaning forward only
a few degrees the gastrocnemius must contract to support the entire body. Relaxed erect
posture is principally ligamentous with only the gllstroc.soJeus muscle group active

To study the erect person functioning in anterior-posterior plane, it is
best to view him from the rear because it will then be possible to see the
deviations from the normal in their relation to an imaginary vertical
The upright supporting beams of the pelvic floor are the legs, and if
the parallel legs are equal in length the supported platform will be
horizontal. If the tibia and femurs of both legs are in direct alignment
and of equal length, the femoral heads must be equidistant from the
ground, and the transverse axis through the femoral heads must be

FICURE 29. Spinal alignment fronl anterior·posterior aspecl Anterior·posterior view of
the erect human spine. With both legs equal in length the spine supports the pelvis in a
level horizontal plane and the spine, taking off at a right (9Cklegree) angle, ascends in a
straight line. The facets shown in the enlarged drawing on the right show their parallel
alignment and proper symmetry in this erect position

FIGURE 30. Pelvic obliquity and its relationship to spinal alignmenl Anterior view of
,an oblique pelvis due to a leg-length discrepancy. Owing to pelvic slant in a lateral plane
the spinal take-off is at a lateral angle. The flexible spine will curve in an attempt to
compensate, and the facets of the curving spine will become asymmetrical in relationship
to each other

horizontal. Balanced between these two points the pelvis will rotate
.around a level axis
In the static spine a level pelvis viewed from behind will reveal the
spine ascending from the pelvic base at right angles and so continuing
cephalad will find the head perched in direct mid-line over the center
of the sacral point (Fig. 29). This head-pelvic center relationship obviously
presupposes a straight spine.
A structurally straight spine of adequate flexibility will permit symmetrical
bilateral side-bending. When we recall that lateral spine
movement occurs in the thoracic region and not in the lumbar area, an
equal degree of bending to the left or to the right will demand that the
.midpoint be level. This action requires a truly vertical lumbar spine
Symmetry in the act of Side-bending requires lateral flexibility of the
spine. As no significant lateral bending occurs in the lumbar spine the
angle of take-off from the lumbar spine at the pelvic level will determine
the amount of correction the dorsal spine must take to effect a
return to the center of gravity.
Another important factor is leg-length discrepancy which will cause a
pelvic obliquity. The causes of leg-length differences are numerous. A
unilateral genu valgum or unilateral genu recurvatum will cause the
side involved to be of shorter length. A unilateral leg-length discrepancy
can result from fractures, articular disease, amputation per se or
,from an improperly fitted prosthesis. Childhood diseases (such as osteochondrosis
poliomyelitis, and hip dysplasia), that may impair unilateral
leg growth, can lead to unequal leg lengths in adult life. The
effect of leg-length difference on the pelvic level has an apparent
influence on the static spine when it is seen from the anterior-posterior
position, and the obliquity of the pelvis has an equal effect on the
(kinetic spine (Fig. 30