Back Strong & Beltless - Part I
Paul Chek
Introduction
When it comes to lifting heavy, a weight belt is more often a fashion
accessory than an essential piece of workout gear. How many of you remember the
only time anyone wore a weight belt was in the gym and only when they were
performing heavy squats, heavy dead lifts, or heavy overhead presses? Now it seems virtually everyone is wearing a weight belt!
Regardless of how heavy someone's lifting or what exercise they're performing
men, women, Arnold wannabes, weekend warriors, and even the elite few who make
the cover of Powerlifting USA are all wearing weight belts.
You've all heard the mentality. Squats? "You MUST wear a belt." Bench
presses? "You should probably wear a belt." Biceps curls? "To be on the safe
side, wearing a belt may be a good idea." Getting a drink of water from the
drinking fountain? "Hell, you may as well leave it on since you'll be wearing it
for your next set." This scenario does not pertain to everyone, but the point
I'm making is that a trend we never used to see in a gym, is one we're seeing
more and more everyday.
It's getting ridiculous and way out of hand.
To make matters worse, the trend to wear a weight belt has extended beyond
the gym. Trash collectors, truck drivers, and construction workers often spend
their entire workday wrapped in a weight belt. Some companies have gone so far
as to make it a mandatory safety policy that all their employees wear a back
harness. Visit any Home Depot, Office Club, or take a look at the waist of your
local package delivery person. What do these employees all have in common?
They're all wearing weight belts! Next thing you know, it will not only be
against the law to drive without a seatbelt, it will be against the law
to operate a vehicle without a weight belt!
What's going on here? Do weight belts really protect our back? Will they make
us stronger? Can the estimated 35-40 percent of people reporting back pain each
year, or the 70 percent of the population who will suffer from at least one
episode of back pain in their lives (1) find relief, and possibly even avoid
surgery, by making a weight belt a habit?
Before I answer these questions, try to dig up recent pictures of the world's
best Olympic weightlifters in competition, but not the American weightlifters
who are losing the struggle to achieve international respect. Look at photos of
European weight lifters who are continuously breaking records and winning world
and Olympic titles. Isn't it interesting that Europeans never use belts when
they perform the snatch lift? They're rarely seen using one for the clean and
jerk! Even during training, you'll find that many of these lifters prefer to
train without any forms of artificial support. In fact, IronMind Enterprises (2)
sells videos of these athletes squatting over 300kg (660lbs) without a belt!
Either these athletes are asking for an injury, or they know something we don't.
When Did Belt Use Get Started?
A look through David Webster's book, The Iron Game, demonstrates that
there is a long history of belt use in connection with heavy weight training
(3). Thomas Inch, publisher of Scientific Weight Training (1905), is
shown pressing two adult females overhead with one hand, "while wearing a weight
lifting belt." This guy was no slouch either. He could clean and jerk 92.5
kilograms (203.5 pounds), perform the "Right Hand Anyhow and Bent Press" lifts
with 96.8 kg. (213 pounds), and he could snatch 67.3 kg. (148 pounds). Not
impressed yet? Perhaps I should mention that he performed all these lifts using only one hand.
American Olympic lifter J. Terpak is pictured wearing a weight belt during
his gold medal performance in the 1937 World Championships in Paris, France.
Later during the 1958 World Championships held in Stockholm, Sweden, an American
athlete named Berger is pictured on the Bantamweight winner's platform wearing
his weight belt. It's interesting to note however, that even though there are
numerous pictures showing winning and highly accomplished lifters wearing weight
belts in David Webster's Iron Game, there are even more pictures that
don't.
One has to wonder, what is it that leads a lifter to use a belt? Is it
direction from coaches, did these particular lifters have back pain in their
lifting history, did they only wear the belts when performing competition or
"max" lifts, or was a belt simply looked upon as an insurance policy?
With a long history of corset use in the medical field, particularly for back
injury, perhaps the lifters have been influenced by the medical approach to
treating back pain. Corsets have been used since the early 1900's for the
treatment of Scoliosis (4) and back pain (5) and quite possibly much longer.
Therefore it is logical that a lifter, wanting to make the right decision, would
choose to use a belt based on the medical establishment's use of belts,
especially considering the history and treatment of back pain dates all the way
back to 1500 BC (1)!
Did Developmental Man Wear Weight Belts?
Regardless of your opinion about the origin of man, if you believe in God,
you have to wonder why he didn't provide weight belts as standard-issue
equipment (Figure 1). On second thought, maybe he did, and we just don't know
how to use them correctly. Perhaps we abuse our bodies, which creates a
dysfunction in our "natural weight belt" and causes us to be reliant on an
artificial one.
A Look at The Belt God Gave You
Today, our understanding of the stabilizer system is at an all time high,
thanks to the works of people like Richardson, Jull, Hodges, Hydes,(6) Vleeming,
Snidjers (7) and Gracovetsky (8). Because of them and others, we have been able
to progress beyond the developmental knowledge of medical doctor Robert W.
Lovett (4) and Anatomist Raymond Dart (9). In 1912, Lovett created detailed
diagrams indicating how the musculature of the torso worked together to
stabilize the spine. Later, in 1946, Dart described the double spiral mechanism
of the spinal musculature, expanding beyond the concepts described by Lovett.
What modern researchers have been able to do is more clearly define two major
stabilizer systems of the body, the inner unit and the outer unit (6,7,8). The stabilizer system considered as our "God-given weight belt" is the
inner unit (Figure 2).
Figure 2 - The Inner Unit (Sagittal View)
The Inner Unit serves to stiffen the axial skeleton in preparation for work.
The Inner Unit muscles are:
A) Transversus Abdominis and the posterior fibers of obliquus
internus,
B) Diaphragm,
C) Deep Multifidus,
D) Pelvic floor musculature. |
The inner unit is composed of the transversus abdominis (TVA),
some fibers of the obliquus internus (IO), the musculature of the pelvic floor (PFM),
the multifidus and the diaphragm (6). Although there is a definite working
relationship among the inner unit muscles, the TVA appears to be the key muscle
of the inner unit system.
In studies of people without back pain, it was found that the TVA fired 30
milliseconds (ms) prior to shoulder movements and 110 ms before leg movements
(6). It should also be noted that though there are slight variations in timing
relative to the motor pattern selected or direction of the postural
perturbation, there is synergistic recruitment of all inner unit muscles.
However, the TVA appears relatively consistent in its activation pattern,
regardless of movement plane or pattern (6,10,11,12). Researchers propose that
the nondirectional, specific activation of the TVA relates to the dominant role
played by the TVA in providing spinal stiffness (6,10,11,12,13,14).
The TVA, in concert with other inner unit muscles, (Figure 2) activates to
increase stiffness of spinal joints and the sacroiliac joints (6,7,15).
Activation of the inner unit provides the necessary stiffness to give the arms
and legs a working foundation from which to operate. Failure of the TVA to
activate 30-110 ms prior to arm or leg movements respectively has been
correlated with back pain and dysfunction (6, 16). The inner unit is part of a
system of stabilizer mechanisms, all of which are dependent on the integrated
function of all inner unit muscles. To better appreciate how the inner unit
creates stability in the body, let's look at each of the proposed mechanisms of
stabilization: Thoracolumbar Fascia Gain, Intra-Abdominal Pressure and the
Hydraulic Amplifier Effect.
Thoracolumbar Fascia Gain
Studying the anatomy of the TVA makes it clear that contraction of this
muscle can only produce one action, drawing in the abdominal wall. This
is evidenced by movement of the umbilicus toward the spine (Figure 3).
Figure 3 - The Inner Unit (Transverse
View)
When activated, the transversus abdominis and posterior fibers of the
obliquus internus draw the umbilicus inward toward the spine (see arrow).
This creates intra-abdominal pressure and hoop tension, which serve to
stabilize the lumbar spine. |
The synergistic action of the TVA and IO produce a characteristic hoop
tension through the thoracolumbar fascia (TLF), (Figure 4) which has been
shown to create an extension force on the lumbar spine (8,17). This is referred
to as thoracolumbar fascia gain. TLF gain is thought to be an important
element, buffering the transfer of force between the muscular and ligamentous
systems during forward bending or rising from a forward bent position. The point
at which the force transfer occurs is called the critical point, occurring at approximately 90 percent lumbar flexion (17).
Figure 4 - Thoracolumbar Fascia Gain
Mechanism
Contraction of the transversus abdominis and obliquus internus generates
lateral tension on the thoracolumbar fascia. The superficial lamina of the
posterior layer of thoracolumbar fascia generates tension via its
attachments at L2 and L3 (yellow), while the deep lamina generates tension
upward through its attachments at L4 and L5 (blue). These mutually opposing
vectors tend to approximate or oppose separation of the L2 and L4 vertebra
and the L3 and L5 vertebra, creating what is referred to as "thoracolumbar
fascia gain" (8,17,21). |
Intra-Abdominal Pressure
As the TVA is activated, drawing the abdominal wall inward, the viscera are
pushed upward into the diaphragm and downward into the pelvic floor, creating
intra-abdominal pressure (IAP). The pressure of viscera upon the diaphragm and
pelvic floor is referred to by Wirhed, as the piston effect (18). When
the viscera rise secondary to TVA contraction a lift pressure is created under
the diaphragm. As you are likely aware, when lifting a heavy object or exerting
yourself to throw or move an object such as in work or sports, it is natural to
hold the breath. Holding the breath under load is associated with increased
tension in the diaphragm. The concomitant elevation of the viscera against a
tightening or tightened diaphragm from holding our breath produces a lift force
through the cura of the diaphragm, which attach at the L2 and L3 level. Wirhed
believes this to be a major contributing factor of spinal stabilization and
joint/disk protection by reducing compression of the lower lumbar discs by as
much as 40 percent (18) (Figure 5).
Figure 5
Intra-abdominal Pressure Mechanism Applied
When lifting any heavy object, the load is transmitted downward through the
spine to the legs (A). To stabilize the axial skeleton and minimize
compressive loading of the lower lumbar segments, the transversus abdominis
and posterior fibers of the obliquus internus should draw the umbilicus
inward. The hoop tension created by activation of the deep abdominal wall
pushes the viscera upward into the diaphragm and downward into the pelvic
floor (B). Because of the innate tendency to hold one's breath while under
load, there is increased tension in the diaphragm. Wirhed proposes this
mechanism may decompress the L4 and L5 segments by as much as 40 percent
(18).
|
White and Panjabi (19) used an analogy of a football in the abdominal cavity,
stating that IAP and thoracic cage pressures may be factors in providing
mechanical stability to the spine (Figure 6).
Figure 6
White and Panjabi's "Football" Concept of Intra-abdominal Pressure
It is theorized that intra-thoracic pressure created by filling the lungs
and intra-abdominal pressure (demonstrated here as a football in the
abdominal cavity) work against each other to support the torso when lifting
an object. Practical experimentation in the gym will show that the trunk is
stiffer when filling the lungs as opposed to not filling the lungs with
inhalation. |
More recently, it has been shown that IAP does provide a stiffening effect on
the lumbar spine, but that IAP is most effective at stabilizing the spine when
applied in concert with co-activation of the erector spinae muscles (20).
It has also been suggested that IAP does not stabilize the spine. Standing
firmly against the notion that IAP provides any significant stabilizing
mechanism for the spine are Gracovetsky and Bogduk (21 p.122). These experts
have sited the following reasons for the ineffectiveness of IAP as a stabilizer
of the spine, contrary to previous belief:
- To generate any significant resistance to the heavy loads being lifted by
athletes and workers, the pressure required would exceed the maximum hoop
tension of the abdominal muscles.
- Such pressures would be so high as to obstruct the abdominal aorta.
- When the abdominal muscles contract to produce IAP, they produce flexion
of the trunk, which would negate any extension quality produced by IAP.
Therefore, it is likely that the stiffness of the abdominal muscles
generating the IAP increase spinal stability. In other words, activation levels
of all trunk muscles determine the stability of the spine, regardless of the
magnitude of IAP (20). Although, as suggested by Gracoskevetsky, we can not rely
on muscles alone because mathematical modeling shows that Olympic athletes would
not be strong enough to lift the loads they currently are lifting during
competition (8). We must look to the fascial system of the body for a missing
link, the hydraulic amplifier effect.
Hydraulic Amplifier Effect
The hydraulic amplifier effect, originallytheorized by Gracovetsky (8)
to increase the strength of the back muscles, was later proven mathematically to
increase the strength of the back muscles by 30 percent (21 p.124-125). The
hydraulic amplifier mechanism is composed of the TLF surrounding the back
muscles to create a relatively stable cylinder (Figure 7) (22). As the back
musculature contract within the cylinder created by the investing fascia, a
hydraulic effect is created, aiding in the erection of the spine from a flexed
position.
Figure 7 - The Hydraulic Amplifier
Mechanism
Gracovetsky (8) has demonstrated with mathematical modeling that the
extension force produced by expansion of the erector spinae muscles within
the compartment created by the thoracolumbar fascia and lamina groove of the
spine is a significant contributor to one's ability to lift a load. The
expansion of the muscles within the thoracolumbar fascia produces
intra-compartmental pressure (ICP). The cylinder is stabilized by
synergistic activation of the transversus abdominis (TVA) and posterior
fibers of the internal oblique (IO). |
To better understand how the hydraulic amplifier effect works, imagine taking
a spine model and gluing a bicycle inner tube along each side of the spinous
processes in the lamina groove. Once adhered, if you were to begin pumping up
the tube (back muscles) inside a stable cylinder (TLF), it would begin to erect
the previously flaccid spinal column (Figure 8). This is the basic premise of
the hydraulic amplifier.
Figure 8 - The Hydraulic Amplifier
Mechanism Demonstrated As demonstrated by this junior scientist, a
bicycle inner tube pumped up inside a cylinder representative of the
thoracolumbar fascia will create an extension force. |
The Outer Unit
The outer unit consists of many muscles such as the obliquus externus,
obliquus internus, erector spinae, latissimus dorsi, gluteus maximus, adductors
and hamstrings working in concert with the inner unit musculature and fascial
systems.
A simplified version of the inner/outer unit systems, seen in Figure 9,
depicts a pirate ship's mast as a human spinal column. While the inner unit
muscles are responsible for developing and maintaining segmental stiffness, the
bigger muscles, shown here as guide wires, are responsible for creating
movement.
Figure 9 - The Inner and Outer Units
Simplified
The outer unit muscles of the trunk demonstrated here (A) rectus abdominus,
(B) internal and external oblique, (C) erector spinae; the outer unit
actually contains other muscles, which have been excluded for
simplification. The inner unit, which contains all the muscles demonstrated
in Figure 2. is demonstrated here as (D); the multifidus acting as segmental
stabilizers for the purpose of controlling joint stiffness. To tighten the
guy wires (A-C), which provide gross stabilization of the ship's mast
without synergistic tightening of the segmental stabilizers (D) would
obviously result in increased potential to buckle the mast. The mast
represents your spine! |
As you can well imagine, if the inner unit were to fail or even suffer
altered function under the load of outer unit functions, the mast (spine) could
easily buckle, resulting in spinal injury. Judging by the statistics on spinal
injury, and the authors of clinical experience, it is evident that the
population at large commonly suffers from an imbalance between the inner and
outer units.
When the inner and outer units are functioning synergistically, there is a
characteristic look to the abdominal wall (Figure 10 A-B). There is a noticeable
oblique line and the umbilicus moves toward the spine as the torso moves through
the zone of the critical point (23). Although an explanation of the outer unit
is beyond the scope of this article, a reader interested in more information may
review "The Outer Unit" (24) as well as references (7), (15) and (23) for a
comprehensive understanding of the outer unit system.
Figure 10
Inner Unit and Outer Unit Synergy
A) If your outer unit is
dominant over your inner unit, as you bend forward to pick up a load, a
string placed around the waist will become tighter as you pass through the
critical point (~90 percent lumbar flexion). If the load is significant
enough to require activation of both inner and outer units, the string will
have become loose as you bend forward and tight as you lift the load.
B) When the inner unit is strong enough to provide adequate
stabilization, you will stay under the stabilization threshold as you pass
through the sticking point. Staying under the stabilization threshold is
indicated by the fact that the rectus abdominis and external oblique
musculature have not shortened and thickened, pressing on the string. |
Now that you have a better understanding of how our own internal
weight belt works and how it functions to stabilize our spine, Part II of this
article will analyze some commonly sited reasons and supposed benefits for using
a belt. I will show that the reasons most people use belts may actually be
providing a false sense of security and potentially setting the belt user up for
injury.
Belts, Are They as Good as People Say They Are?
Certainly, if you could come up with a product that supposedly reduced pain
at the same time that it improved performance, or at least appeared to, you could make A LOT OF MONEY! Just take a look around you next time you are at
the lumberyard, warehouse, or office supply store. Chances are you will see
employees wearing belts. As I eluded to in the introduction, many furniture
moving companies, chain store organizations and package delivery companies have
made it mandatory for employees to wear belts.
Have the decisions made by companies, corporations, workers and gym members
been based on sound research? Perhaps. But maybe it has been the scare tactics
and strong marketing techniques of belt companies that have helped people make
their decision.
There is certainly no shortage of claims being made by belt manufacturers.
For example, here are two claims I pulled directly from the "Valeo" belt
company's web
site:
- The support helps workers perform their duties while helping to protect
their back from stress and strain damage.
- Reduces the likelihood of pain or injury for a variety of activities.
If you can market a product based on fear and emotion (both of which
are highly correlated with the back pain experience), chances are you will sell
that product and lots of it! Famous speaker, Zig Ziglar, states that
F-E-A-R is really False Evidence Appearing Real
(25). This, in my opinion, is the case with weight belts in general.
Apparently, the evidence supporting the use of back belts did not even appear real to Lahad et al (26), who identified 190 articles from 1966 to
1993 that focused on various interventions for the prevention of low back pain.
Lahad et al (26) concluded that sufficient evidence was unavailable to recommend
the use of mechanical back supports for the prevention of back pain (27). In
another study conducted by the National Institute for Occupational Safety and
Health, prophylactic use of back belts for healthy workers was not recommended
because of a lack of scientific evidence promoting their benefit (27,28). There
are also many other studies indicating belt use provides no significant
improvement in performance or reduction in the user's chance of injury (29-34).
Getting to the Bottom of the Elusive Obvious
To make this review of belt use complete, it must be stated that there are
numerous studies indicating the use of back belts, weight belts and lumbar
corsets improves performance, endurance, and reduce chances of injury. I have
sited these studies in the reference list (35-40). Even though there are studies
demonstrating a supposed increase in performance while using weight belts, there
are many, if not more, studies indicating weight belts are damaging and even
worse, create dysfunction in their users.
As most of you reading this article are aware, many gyms have racks of weight
belts, as a service to their members. I have already mentioned their
widespread use in the industrial workplace. So then, if as stated above, a
government agency devoted to occupational health and safety doesn't support belt
use due to lack of scientific evidence (27,28), then what are the belts
providing that lead people to believe they help reduce pain, prevent injury or
improve performance?
The Weightlifting Encyclopedia - A Guide To World Class Performance, a
respected book among weightlifters, sites four reasons for a competitive
weightlifter to wear a belt (41):
- The belt itself can offer some support (i.e. to the extent it resists
bending, it can provide an external physical force against which the body can
exert a force).
- The lifter can exert some outward force against the belt with the muscles
of the torso (primarily the abdominal muscles), helping achieve rigidity in
the torso.
- The pressure of the belt can help to remind the lifter to maintain the
correct position of the spine and the proper degree of tension in the lower
back muscles.
- The belt can help to keep the area it covers warm.
In an attempt to assist the reader with a more comprehensive understanding of
how workers and weightlifters have developed unfounded security in supportive
back belts, I will analyze each of these four benefits.
Alleged Belt Benefit No. 1
The belt itself can offer some support (i.e. to the extent it resists
bending, it can provide some physical force against which the body can exert a
force).
This is true . . . the belt can offer the body some support. The support a
belt offers is deceiving, though. To appreciate how the support offered by a
weight belt can improve performance, we must first analyze the concept of hoop tension.
Hoop tension is created anytime you create tension around a joint or joints.
For example, if you were to grasp a snake in your hand, you would be applying hoop tension to the snake's body with your hand, in effect immobilizing the
vertebral joints of the snake's spine that were in your hand (Figure 11). The
snake would still have movement above and below the region of hoop tension.
Powerlifters have been capitalizing on hoop tension for years through the use of
knee wraps, wrist wraps, weight belts and body suits which all create hoop
tension around one or more joints.
 Figure 11 - Hoop Tension Demonstrated
Left: Without external influence from hoop tension, the snake's spine (like
the lifter's) is free to move, under direct influence of the snake's muscles.
Right: When you grasp a snake, you create hoop tension around the snake's
body with your hand, immobilizing the snake's vertebra. Although the snake will
continue to try and wiggle out of your hand, it will be unable to produce gross
movements of its spine in the region of hoop tension as produced by your hand.
If filmed with motion X-ray, you would see that the vertebra are demonstrating
small segmental movements (compression, torsion, sheer) as a result of muscle
actions.
With regard to the human spine, we cannot ignore the anatomical fact that the
TVA and IO are optimally designed and situated to create hoop tension through
the thoracolumbar fascia (see Figures 2 & 3). Through its middle layer, the TLF
communicates directly with the spinous processes of the lumbar spine (6,7,8,21).
Therefore, any increased hoop tension created by the TVA and IO would serve to
not only increase IAP, but it would also increase segmental joint stiffness and
serve to stabilize the spine in all planes of motion (6 p. 55-58) (Figure 12-A).
This is not the case when creating hoop tension with a weight lifting belt.
First, hoop tension is created manually when the user tightens the belt. Second,
hoop tension, as measured against the belt, will rise as the lifter pushes his
or her abdominal wall into the belt. When pushing the abdominal wall outward
into the belt, the umbilicus moves away from the spine which can only decrease
hoop tension created by the TVA and IO. This action of pushing out decreases segmental joint stiffness, which means that gross recruitment of the
rectus abdominis and obliquus externus pushing against the belt can only create
gross spinal stabilization and compression of the relevant joints (Figure 12-B).
| Figure 12 A & B
Intrinsic Hoop Tension vs. Extrinsic Hoop Tension and Spine Stabilization |
A1) Because the transversus abdominis
and internal oblique muscles place lateral tension on the thoracolumbar
fascia, which is intimate with the transverse processes and spinous
processes of the lower lumbar segments (A2), intrinsically generated
hoop tension actually provides segmental stability.
B1) Tightening a weight belt around the waistline compresses the
abdominal viscera, but there is no direct connection to the spine itself. B2) Although the belt provides gross stability/immobility through
increased intra-abdominal pressure (much like the snake in Figure 11), the
compressive loading and faulty recruitment patterns often associated with
lifting with belts may continue to produce aberrant motions at segmental
levels of spinal joint structures. Once the belt is removed, the same faulty
recruitment patterns, unaided by the gross stability of the belt often
result in joint derangement, particularly in the L4/5 and L5/S1 motion
segments. |
If you look back at Figure 9, you can easily imagine what would happen to the
mast of the pirate ship if a large wind were to hit the sails, loading the large
stabilizing guy wires in absence of a corresponding increase in segmental
stiffness.
In fact, research backs my point. Axelsson et al. studied the effects of
lumbar orthosis on intervertebral mobility using a sterophotogrammetric x-ray
analysis (42). In this study, they used two types of back supports: the first, a
molded, rigid orthosis and the second, a canvas corset with molded, plastic
posterior support, each of which is far more comprehensive in design than a
traditional weight belt.
They concluded that neither of the two types of lumbar support had any
stabilizing effect on the sagittal, vertical, or transverse intervertebral
translations. Additionally, they stated that lumbosacral orthosis illicit their
effect by restricting gross motions of the trunk rather than the intervertebral
mobility in the lumbar spine (42).
Furthermore, Miller et al., studied three types of lumbosacral corsets,
concluding that "no brace could adequately immobilize the L5-S1 level, and some
people demonstrated increased motion at this level while wearing the orthotics"
(43). The disturbing aspect of this is that all of the forms of support in these
studies are far more comprehensive in design than a weight belt, and if they don't provide intervertebral stability, then what good will a weight belt do?
Alleged Belt Benefit #2
The lifter can exert some outward force against the belt with the muscles of
the torso (primarily the abdominal muscles), helping achieve rigidity in the
torso.
Recruitment of trunk stabilizers via EMG with and without a weight belt has
been studied. These studies concluded there was increased recruitment of the
erector spinae and rectus abdominis when wearing a belt (40,44). Now that you
understand the workings of the inner unit, it should be evident that by
recruiting the larger, gross stabilizers without proportionate
recruitment of the inner unit musculature responsible for regulating joint
stiffness, the result could certainly lead to spinal joint dysfunction or
exacerbate an existing condition. It is also likely that prolonged use of weight
belts will result in coordination problems within the inner unit muscles and
among the inner and outer unit systems.
Clinically, when treating injured weightlifters and workers, I find it common
that belt users suffer from what I call "rectus abdominis dominance" (Figure 10A & B). It is also rare, extremely rare in fact, to find someone who
uses a weight belt and has normal TVA function according to tests outlined by
Richardson, Jull, Hodges and Hydes (6) (Figure 13). My clinical findings also
correlate with current research, which indicates that those individuals with a
reduced ability to draw in the abdominal wall have inconsistencies in the
coordination of the TVA and related inner unit musculature (45).
Figure 13 - Transversus Abdominis
Testing
To begin, place the bladder of the Blood Pressure Cuff (BPC) placed directly
under the client's umbilicus. Pump the BPC to read 70 mmHg after exhalation;
if 70 mmHg is uncomfortable, any even number between 40-70 mmHg will work.
Instruct the patient/client to completely relax, exhale and draw their
umbilicus off the BPC. Watch carefully to make sure they are not pressing
downward with their arms, flexing their hips or activating their gluteus
maximus muscles. An indicator of normal TVA activation is demonstrated by
the ability to reduce the pressure reading by 10 mmHg. Those with faulty
recruitment patterns commonly increase the pressure registered on the BPC,
which is an indicator of rectus abdominis dominance; a common finding among
belt users. |
Many of these patients suffer form chronic back pain, intermittently
disrupting their training. They also commonly state that there is a significant
difference in lifting performances with and without their belt, being much
stronger with the belt. This common finding among most belt users is an
indication of what I call a "stabilization deficit". In other words, the
greater the difference in load lifted, with, versus without, a lifting belt, the
greater the indication that the CNS is down-regulating motor unit recruitment to
protect unstable, inflamed and/or painful articular structures. Adding a weight
belt, which creates hoop tension, increases gross stability in a body
that is likely suffering from reduced ability to stiffen joints segmentally and
has coordination deficits within the core.
Research by Cholewicki et al. (46) indicates that "inappropriate coordination
of trunk muscle recruitment patterns to stabilize the lumbar spine through
antagonistic co-activation and IAP, may predispose an individual to sustain a
low back injury during a physical activity." The faulty recruitment patterns
that result from belt use are logical when considering that the body's motor
system is organized as a "sensory-motor system."
When strapping a belt tightly around your waist, surface receptors in the
skin are stimulated. The sensory nerves serving the cutaneous tissue beneath the
belt have a sensory-motor relationship with the muscles under the skin. This
relationship is well explained by Hilton's Law, which states, "The nerves which
supplied the muscles and controlled the movements of the part (joint) also
served the skin and other sensory surfaces which were connected with that part"
(47).
Davis' Law is demonstrated and well known by physical therapists who treat
neurological injuries; stimulating the surface of the body produces stimulation
of the muscles served by the same nerve root (48 p.137). Therefore, repeatedly
"pushing outward" against the belt, which is encouraged by the belt through
sensory-motor stimulus, is likely to develop and perpetuate faulty recruitment
patterns.
Lifters may go uninjured for years under these conditions, yet research and
clinical experience show it is likely they are setting themselves up for injury!
If belts really did improve trunk stability, then the lifter would be able to
use them for a given period of time, remove the belt and experience improved
performance when lifting; THIS IS NOT THE CASE!
Sensory-Motor Amnesia
The concept of sensory-motor amnesia was popularized by Thomas Hanna in 1988
(53). Hanna used the term to describe a motor deficit resulting from lack of
sensory stimuli. Clinically, sensory-motor amnesia is a common finding among
people that do not use their body adequately to keep the motor system stimulated
and by people that stopped moving part of their body secondary to pain
avoidance.
In my 16 years of clinical practice, I have had adequate experience
rehabilitating injured athletes and workers that were belt users prior to
seeking my assistance. Due to my experience, I can assure you a high rate of
sensory-motor amnesia exists in many belt users' deep abdominal wall. I've found
this is due to the fact that belt users, using extroceptive stimuli from the
belt, learn to push their abdominal wall outward, into the belt. The
result is that they not only go for extended periods without using their deep
abdominal wall (TVA and IO), the deep abdominal wall becomes weak, and the brain
can often no longer recruit those muscles.
The only way to restore function of the deep abdominal wall is to use various
forms of biofeedback (described below). Additionally, injured clients must be
taught how to lift and move correctly while learning how to sequence the inner
and outer units for synergistic action and injury prevention. A big part of this
rehabilitative process is weaning them off the belt! (See below for instructions
on how to do this.)
Alleged Belt Benefit #3
The pressure of the belt can help to remind the lifter to maintain the
correct position of the spine and the proper degree of tension in the lower back
muscles.
The benefit stated above is one of the reasons lifters commonly give to
justify their use of belts. Improved proprioception is cited as an additional
benefit of belt use in medical literature (49). Reduced lumbar proprioception
after back injury has been recognized by physical therapists (50) and proven to
exist among back pain patients in a controlled study (51). It is very likely
that many belt users recovering from a back injury began using a belt because of
instruction to do so by a doctor or therapist in an attempt to re-establish
proprioception. It may also have been prescribed to reduce the fear of
re-injury.
Proprioceptive deficits in the lumbopelvic region are common among back pain
patients. Such deficits are often demonstrated by the patient as an inability to
differentiate anterior pelvic tilt from posterior pelvic tilt when positioned by
the therapist. Proprioceptive deficits in the lumbopelvic region are also
recognized by the patient's inability to actively return to a target position or
to recognize the position when placed there passively.
Although wearing a back belt or weight belt may be of some benefit to the
individual who has a proprioception deficit, my clinical experience dictates
that it is not because the belts enhance proprioception. Exteroceptors are
classified as "One of the peripheral end organs of the afferent nerves in the
skin or mucous membrane, which respond to stimulation by external agents" (52).
Therefore, belts are a source of exteroception.
This is an important distinction to make because exteroception (touch, heat
and pressure (48 p. 145)) from the belt only improves one's sense of position when worn. This means that if the worker or athlete forgets their belt and
is faced with having to perform lifting tasks, they are faced with greater risk
of injury because they have not learned anything from using a belt. Many of the
back injuries among belt users I have treated over the years came when they
forgot their belt, or did not have it secured adequately to produce the needed
exteroception.
If indeed belts did improve proprioception, the user would be able to take
the belt off after a period of use and have improved proprioceptive sense or
"position sense" while lifting. This would constitute a learning effect; I have never experienced this to be the case! Belt users become dependent upon their belt, making the belt more of a crutch than a training device.
Improving proprioception requires special exercises that are usually taught
by a skilled physical therapist, movement therapist or corrective exercise
specialist. As the patient progresses, they are able to better detect their body
position in space, demonstrating increased kinesthetic awareness, and thereby
demonstrating a belt is not necessary.
It is very valuable to use other extroceptive stimuli, such as athletic tape
to improve kinesthetic awareness. As the patient learns, the need for tape is
reduced, and eventually the tape is eliminated. String is also used as a form of
biofeedback during movement training and is particularly useful in restoration
of deep abdominal wall function during functional movement training (23, 54).
The use of string as a biofeedback mechanism will be discussed below.
Alleged Belt Benefit #4
The belt can help to keep the area it covers warm.
The use of a weight lifting or back belt to keep the area warm can easily be
accomplished by any insulating material; wet-suit material is commonly used for
this purpose. In light of the many concerns regarding the use of weight belts
discussed in this article, it is apparent that performing a proper warm-up and
using other materials to keep heat in the tissues is advantageous and superior
to weight belt use.
Click HERE to read Back Strong and Beltless - Part II! |
