Back Stiffness: Exercises And Stretching
Some researchers report that back stiffness is a symptom of low back pain, rather than the cause of it.
This concept makes sense if you understand how the muscles of your back work.
In recent review in Manual Therapy, Mark Comerford, PT and S. L. Mottram
propose a new model of muscle classification. They divide muscles into three groups:
(1) Local stability muscles.
(2) Global Stability muscles.
(3) Global mobility muscles.
Global mobility muscles are the large, strong,
torque-generating muscles that produce range of motion. A global mobility
muscle will react to pain and pathology with spasm. They also
become overactive for low threshold recruitment during low load activities.
Examples are:
-
erector spinae (longissimus,
iliocostalis),
-
quadratus lumborum (lateral fibers),
-
piriformis.
So if back stiffness is a result of excessive
activation or spasm of global mobility muscles, then we have to ask another
question before we decide how to treat it.
Why does back stiffness occur?
On previous pages on this website, I explained
that inner unit muscles become impaired with pain and pathology. (The
inner unit is synonymous with local stability muscles).
Local stability muscles react to pain and pathology with motor control
impairments that may include: delayed timing, recruitment
deficiency, decreased muscle stiffness, poor segmental control, and loss of
control of joint neutral position. These problems have been found to
persist after lower back pain symptoms have resolved and the patient has
returned to normal activities.
Limited ultrasound scanning allows
us to visualize specific findings of impairment or dysfunction of the deep
stabilizing muscles (local stability muscles), these may include the
following:
-
A significant reduction of cross-sectional area of
a segmental portion of multifidus on the painful side.
-
Poor recruitment of deep fibers of segmental
portions of multifidus.
-
A significant unilateral loss of muscle tissue
with increased fatty tissue infiltration within the multifidi.
-
Poor ability to recruit transversus abdominis,
independently (from internal oblique).
When the local stability muscles are
impaired or dysfunctional, the brain changes its strategy for low threshold
recruitment during low load activities by compensating with excessive activation
of the global, outer unit muscles for stability. This may also lead to other problems, such as a change in the postural curvature of the spine.
When the thoracic portion
of the erector spinae muscles are overactive and the multifidi are impaired, we observe a
long lordotic curve with the apex at the thoracoclumbar junction. This may
be thought of as a "bow-string" effect. If the string of a bow is
shortened, then the curve of the bow will increase. This also happens with the
spine and because these muscles attach to the thoracic spine, the lordotic curve
becomes longer
than it should be.
Another complicating factor occurs when the upper thoracic spine becomes more kyphotic and stiff
and the individual attempts to become more upright by extending through the
hypermobile segment (typically the thoracolumbar segment). Again this
emphasizes the erector spinae over multifidus recruitment.
During the initial evaluation of this type of
patient (with long lordosis), we would expect to observe that there is no
reversal of lordosis of the lumbar spine during forward flexion. This is
an obvious sign of lumbar spine stiffness.
So how do I treat this type of lower back stiffness?
The initial focus should always be on the local
stability muscles, if impairment is identified. Multiple studies indicate
that these impairments are reversible with specific muscle training. As
the patient progresses, we typically see a relaxation of the global muscles (in
this example, the thoracic portion of the erector spinae) and the ability to
reverse the lumbar lordotic curve while forward bending is re-established.
Your patients will
subjectively confirm that they feel less stiffness in the lower back during
daily activities. But this is only the first step.
Next, we focus on "controlling the give" or
hypermobile mechanical stress point, and "moving the restriction" or the joints
that are stiff and have limited ROM (Comerford).
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