The Use of External Support in the Treatment of Low Back Pain
Jacquelin Perry. M.D. *
The origin of therapeutic procedures can
generally be traced to local efforts directed toward resolving continuing
disability of the patient. In the treatment of low back pain, this approach
often included designing special supports by individual physicians and
orthotists. Such independent activity in numerous locales resulted in a long
list of brace designs, many of which carry impressive eponyms that tend to
stress differences rather than elements of commonality.
To compile the available information
concerning bracing, the American Academy of Orthopaedic Surgeons published the
Orthopaedic Appliances Atlas in 1953. Of the 30 types of spinal
support described in that volume, 17 were specifically designed for the
sacroiliac or lumbosacral areas. Ten years later, in 1962, a survey of
orthopedic services in the United States by Nattress and Litt identified 30
braces, of which 22 corresponded to the design customarily considered effective
at the lumbosacral region. These two reports, along with the present study,
described a total of 40 different devices designed for low back
problems.
Details of designs are readily available,
but objective criteria to weigh the relative merits of the different devices are
almost nonexistent. As a consequence, physicians generally make their selection
either by adopting the customs observed during their training, or by accepting
the preference of the local orthotist. Undoubtedly, some braces have
withstood the test of time, while others have
become items only of historical interest. Superimposed on this background, the
more recent introduction of prefabricated parts for brace construction has
probably influenced the frequency with which certain types of braces are
prescribed.
The extent to which these influences have
altered the availability and prescription of brace designs today has not been
reported. Also unknown is the nature of the relationship between the etiology of
the low back pain and the type of support that clinicians have found to be
effective. Identification of this type of information is pertinent because the
subject of orthotics is now being presented in formally organized courses on a
nationwide basis.
This paper records the results of a
three-phase study conducted in 1968-69 by the Subcommittee on Orthotics,
Committee on Prosthetic-Orthotic Education (CPOE) of the National Research
Council. Approval of the Executive Committee of the American Academy of
Orthopaedic Surgeons was obtained. The purpose of the survey was to identify the
current practices of orthopedic surgeons with respect to external supports for
the management of low back pain.
Method
Pilot Study
An unstructured pilot questionnaire was
sent to 150 orthopedic surgeons selected because of their considerable
experience in the management of low back pain. They were asked to list the types
of support they prescribed, and to indicate the clinical conditions for which
each support was chosen. The results of this pilot
study formed the basis for the next phase of the investigation.
The 90 physicians (60%) who responded
were explicit in their choice of a device and the clinical indication for its
use. Eighty-three reported frequent prescription of external support as part of
their therapeutic program. (Two said they never used external supports, and five
indicated they rarely prescribed such aids.)
Within each class of support (brace,
corset, cast), a similar pattern of practice was evident. Numerous designs were
listed, but most were mentioned only occasionally. The majority of the
respondents preferred one or two types of support. Within a total of 12
different braces reported, three-fourths of the physicians listed the Chairback
(Knight) and Williams braces (Fig. 1, Fig. 2, and Fig. 3). Six other designs were
mentioned only once. Identification of corset preference was a bit clouded by
the indiscriminate use of both generic and trade names. The generic term
"lumbosacral" was specified by half of those responding. An additional
one-fourth of the pilot-study participants used trade names such as Camp,
Spencer, and Winchester. The next most frequently mentioned device was the sacroiliac belt
(8%). Of the six casts identified, the flexion jacket was preferred by more than
half of the pilot-study orthopedists; the second choice was the body jacket
(19%). In designating the clinical conditions warranting external support, two
response patterns developed in the pilot survey. Seven types of disability were
mentioned frequently and in explicit terms, viz., postoperative fusion,
spondylolisthesis, chronic backache, acute strain, disc syndrome, degenerative
joint disease, and the postoperative disc. Several other conditions, identified
by a wide variety of terminology, were mentioned with moderate to rare
frequency.
National Survey of AAOS
The findings of the pilot survey were
used to construct a questionnaire applicable for a comprehensive national study.
This questionnaire was sent to the membership of the American Academy of
Orthopaedic Surgeons (AAOS). The form (presented at the end of this article) was
a check sheet on which physicians were asked to match the types of support they
prescribed with the clinical conditions they treated in this
manner.
The following supports, all of which were
more than rarely mentioned in the pilot study, were included. (The restriction
on corset choice was the result of a decision to use generic rather than trade
names in order to avoid repeating the confusion produced in the pilot
study.)
Braces
- Chairback
(Knight)
- Williams
- Norton-Brown
- Goldthwaite
- Bennett
Corsets
- Lumbosacral
- Sacroiliac
Casts
- Flexion
- Body jacket
- Cast with one
leg
Eleven clinical conditions were selected
for the national inquiry, based upon the
returns of the pilot study and upon the
clinical experience of the NRC committee. Provision was made throughout for
physicians to indicate devices or clinical problems other than those listed on
the form. The questionnaire was also designed to indicate the relative frequency
("usually" or "rarely") of the prescriptions.
Survey of the Functions of Support
Late in 1968, a second national survey
was conducted among the AAOS membership to determine prevailing opinions about
the functions of the various types of support. The purpose of this phase of the
study was to attempt to relate the anticipated function of the external support
to the different preferences in prescription.
Profiting from the findings of part one
of the national survey, the list of supports was again shortened. This time, the
orthopedists were queried about two braces (Williams and Chairback [Knight]);
"corset" was listed as a single category, as were the flexion casts. A
miscellaneous category was added for other comments. (The questionnaire appears
on page 57.)
Six probable functions were selected for
study. These included: immobilization of the spine, restriction of lumbosacral
motion, unloading of the intervertebral disc, support of the abdomen, correction
of posture, and psychological effect. As always, there was a provision for other
choices.
Results
On the first national survey, 5,215
questionnaires were mailed. With the aid of one follow-up, 3,140 (60%) were
returned completed. An additional 1% of the returns were incomplete because the
physicians had retired or their practices did not include patients with low-back
problems.
In the second phase of the study, the
same number of forms were sent out, with 2,192 (42%) being filled in and
returned. No follow-up mailing was conducted,
Annotated responses or explanatory
letters accompanied 1,034 (33%) of the questionnaires. These consisted of:
(a) identification of the type of device they preferred if it was not
specifically mentioned on the form; (b) comments regarding precise
fitting or construction characteristics considered to be important; (c)
reasons for not prescribing external support; and (d) other modes of
treatment which should accompany use of a support.
Use of Supports for Low-Back
Problems
Most of the orthopedic surgeons indicated
use of a judicious selection of braces, casts, and corsets; the average
physician reported that he used three different devices in his practice. A small
group stated that they used only one type of device: a brace (4%), a corset
(4%), or a cast (1%). Only 14 respondents stated that they "never used support"
for the patient with a low-back problem.
Among the clinical indications, the
inclusion of the term "fracture" caused considerable confusion in the
information collected. Either all types of braces are used for fractures in the
"low back," or the orthopedist's attention was directed to fractures of the
spine in general. The latter seemed highly probable, as most indicated that a
brace other than those listed was used. Typically, these were the Jewett,
Taylor, and Baker types, commonly used for lesions in the thoracic and
thoracolumbar areas. As the extent of this confusion could not be identified,
all data referring to "fracture" were omitted from the analysis.
Certain characteristics in the
prescription of external support became evident. A majority of the profession
used the same groups of devices. The nature of the disability dictated the
frequency of prescription as well as the type of support preferred.
Support Preference
The lumbosacral corset is the most
popularly used low-back support, followed by the Chairback (Knight) spinal
brace. Utilization of the other types of support fell far behind these two leaders
Table 1.
The degree of dominance by the
lumbosacral corset varied with the method of comparison; 28.5% of the physicians
indicated use of the lumbosacral corset for at least one condition. When all
clinical indications were considered, preference for the lumbosacral corset was
44.2%. The Chairback brace was used by 21% of the physicians for 22% of the
clinical conditions listed. All other types of support were used less than 9% of
the time. The Williams brace was third in popularity. A variety of casts
preceded any other choice of brace or corset Table 1.
As "lumbosacral corset" is a generic term
that overlooks design differences between the Camp, Winchester, Spencer, and
other specific corset styles, a comparison was made with the designated
preferences for the total group of "low-back braces." The relative preference
between the corset and the low-back brace again depended on the method of
comparison. The use of a brace at some time was indicated by 40.2% of the
physicians, in comparison to 32.4% for corsets. However, when all the clinical
indications were totaled, the preference reversed, with the corsets dominating
(46.7% in contrast to 39.0% for braces).
Some geographic patterns for brace
preference were found, especially for those used less frequently Table 2. The
middle and southeastern sections of the United States were the only areas where
the Williams brace was used widely; it was fourth in preference on the West
coast. With the exception of New York, no mention of it was made in the eastern
or New England states. The Bennett brace was second in popularity in Maryland
and third in Ohio. Predominance of the Norton-Brown brace was
restricted to Massachusetts and Maine, a note consistent with the fact that the
originators are from Boston.
Clinical Indications
The survey form asked the physician to
check whether he rarely or usually used some type of support for each of ten
clinical conditions listed Table 3). Three patterns of use were apparent. The
responding physicians seldom used external support in the treatment of an acute
strain (17%), for an obese person with pain (19%), or during the postoperative
period following disc surgery (28%). When support was used for these conditions,
it was generally a corset.
At the other extreme, most physicians
used support following spine fusion (84%), for treatment of spondylolisthesis
(70%), and for pseudoarthrosis (66%). In these instances, the most common type of support
was a brace.
The orthopedists were evenly divided as
to the advisability of prescribing any type of support in treating the
degenerative back, the disc syndrome of chronic backache, or as a preoperative
trial. A similar lack of agreement was indicated concerning the type of support
preferred. As a preoperative trial, there was equal preference for a brace or
cast. For the other disabilities, the preferred support was the lumbosacral
corset.
Comparison between the specific brace
design and the clinical condition Table 4 showed that the Chairback was
the most frequently used brace in each
situation, and the Williams brace ranked second in preference. Spondylolisthesis
and the disc syndrome were the most common indications for the Williams brace.
Spondylolisthesis was also the primary reason for using the Bennett brace.
Otherwise, preference for the Norton-Brown, Goldthwaite, and Bennett braces
paralleled the use of back support in general.
Function of External
Supports
Three approaches to the data collected on
functions of supports seemed pertinent: the general expectation for external
supports, the types of support chosen for each of these functions, and the
functions expected of each of the support designs.
The function most commonly ascribed for
external support was restriction of lumbosacral motion (30%); abdominal support
was second (19%), followed by postural correction (15%) and immobilization of
the spine (12%).
To restrict lumbosacral motion, the
Chairback (Knight) brace or a corset were equally preferred. The Williams brace
was the third specific device indicated for this purpose, although a larger
number of physicians indicated that they used some type of cast to restrict
motion.
Abdominal support was most often assigned
to the corset. This dominated its next competitor, the Chairback (Knight) brace,
by a ratio of two to one. Again, the Williams brace ranked third for the
function of supporting abdominal muscles.
Postural correction was almost equally
divided between the corset and a Williams brace, although the use of casts was
not uncommon.
An interesting situation developed in the
category of spinal immobilization. It was the only function identified for the
flexion cast, yet this device was fourth in preference. The support most often
indicated for spinal immobilization was the Chairback (Knight) brace, a finding
which probably reflects its national popularity.
While external supports are seldom used
for psychological reasons, when the practice is followed the corset is the most
popular device, followed by the Chairback brace.
The concept of unloading the disc has
obviously not been accepted by the majority of orthopedic surgeons, since only
8% indicated this as a function of external support. However, those who did
think in these terms showed a strong preference for the Williams brace, with a
cast as an alternate.
Focus on the individual types of support
showed that the prime functions of the corset were considered to be abdominal
support and restriction of lumbosacral motion. The Chairback (Knight)
brace was assigned the same functions, but with
greater emphasis on restriction of motion. This function was also considered the
main purpose of the Williams brace, with correction of posture as its second
indication. Casts were generally used to restrict lumbosacral motion, although a
surprisingly larger number were also assigned the function of correcting
posture. Consistent with the belief that immobilization, as opposed to
restriction of lumbosacral motion, is seldom accomplished with external support,
even casts were assigned this as a third function.
In addition to completing the survey
form, a third of the respondents (1,034) added notes to further explain their
preferences. These varied from a single listing of a specific brace to lengthy
letters explaining their philosophies of low-back management. A majority of
these replies were focused on either the fitting or construction characteristics
of their support preferences.
Sixty respondents emphasized the
advantages of using exercise early in the treatment of low back pain. Two
purposes were expressed: to avoid external support and to overcome the muscle
weakening and contracture development that accompanies prolonged immobilization.
One respondent summarized this philosophy very succinctly by stating he "never
prescribed support without a plan to eliminate it." A smaller group (30) felt
that the disadvantages were sufficient to preclude any prescription of external
support. All who said they "never" or "rarely" used support emphasized instead
their reliance on an organized program of exercise. Specific application of this
philosophy was frequently mentioned in relationship to postoperative management
of spine fusions. Many respondents also brought out the fact that the treatment
of low back pain must be individualized to fit the particular patient's need.
This fact must never be forgotten, of course, and the purpose of the survey was
not to contradict the concept of individualized patient care, but merely to
identify the spectrum of external support which
physicians have found adequate to meet their multiple goals.
Discussion
The potential list of 40 external-support
designs for low back pain has been severely pruned by the influences of
prolonged clinical experience, greater intermingling of orthopedists through
professional meetings, and the use of prefabricated parts. Notes by some of the
respondents indicated that cost, emphasis on exercise, and early surgery are
other important influences.
The clinical indications for use or
non-use of external support were rather sharply defined, but there is no
comparable distinction between the accepted styles of support. The latter was
indicated by the overlap between clinical entity and support design, as well as
by the identification of the functions of the different devices. The mechanical
characteristics and the limitations of these various designs which lead to such
ambiguity have yet to be objectively identified.
Investigators have found that, unless
the support is carefully designed, motion at the lumbosacral joint could be
increased with the support rather than
restricted. Personal experience indicates
that this might also lead to increasing the patient's pain.
A problem still not studied is
identification of the characteristics of the patients which govern the choice of
support.
Summary
The lumbosacral corset is the most
commonly prescribed external support for low back pain. The Chairback (Knight)
and Williams braces are next in preference, with a cast being used least
frequently. There is a definite relationship between the etiology of the low
back pain and the type of support chosen. The major indication for support
prescription is to restrict lumbosacral motion.
References:
- American Academy of Orthopaedic Surgeons, Orthopaedic appliances atlas, vol. 1, braces, splints, shoe alterations, J. W. Edwards, Ann Arbor, Mich., 1952.
- Nattress, LeRoy Wm., Jr., and Bertram D. Litt, Orthotic services USA 1962, report 2, survey to determine the state of services available to amputees and orthopedically disabled persons, American Orthotic and Prosthetic Assoc, Washington, D.C., 1962.
- Norton, Paul L., and Thornton Brown, The immobilizing efficiency of back braces: their effect on the posture and motion of the lumbosacral spine, J. Bone Joint Surg., 39A:111-139, January 1957.
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