| The weightlifting
belt is often considered standard issue in the weight room
these days. From the competitive weight lifters to those of
a more recreational interest, all would seem to agree that
there is a necessity for such a device. After all,
supporting the back in order to help prevent injuries while
lifting is a difficult point to argue. It is because of this
seemingly obvious benefit that the concept is beginning to
be used in other areas as well. Besides the weight room,
public and private industry have begun to provide lower back
support equipment for their personnel. It is becoming more
common to see these devices on stock clerks, warehouse and
construction workers, as well as firefighters. While the
intention is certainly prudent, is it actually understood
how weight belts function to support the back? Do the weight
belts in the gym support the back in the same manner as the
back braces used in commercial environments? Is there a time
for wearing a weight belt or back brace that is most
appropriate? Furthermore, is there ever a disadvantage to
wearing a lower back supporting device of any kind?
The answers to these questions
could very possibly alter the thinking as to the use of a
weightlifting belt or back brace. Likewise, the following
information could lead to a decision not to use a weight
belt or back brace at all.
The Function and
Benefits of Lumbar Support
Back braces differ from weightlifting belts in the overall
objective to support the back. In normal populations back
braces are successfully used to offer support in conditions
where low back pain reduction is the primary goal. (1,2)
Physical support as well as psychological comfort have been
noted with these devices. (3) Even people that have not
injured their back often use these corset style braces to
assist them in carrying out their everyday lifestyles. It is
the rigidity of the brace itself that serves to immobilize
the area in a splint-like fashion thus lending support to
the lower back. (4,5,6,7)
The weightlifting belt, contrary to
popular belief, supports the back in a different manner.
While there can be some support due to the rigidity of a
weight belt, the benefit is minimal compared to the support
offered by the increase in the intra-abdominal pressure (IAP).
(8,9,10)
During a normal lifting maneuver
such as the squat; the diaphragmatic muscles along with
muscles of the torso contract generating pressure on the
abdominal cavity. The abdominal cavity together with its
predominantly fluid contents, known as the "fluid
ball", are kept under pressure by the surrounding
musculature. It is this natural intra-abdominal tension that
supports the spinal column. (11) Several studies have shown
that weight belts increase intra-abdominal pressure and
therefore assist in this natural stabilization mechanism.
(3,8,12,13,14) Other studies have shown that increased IAP
by use of the weight belt not only relieves the load of the
musculature of the lower back, but also reduce the
compressive forces on the spinal discs. (15,16,17)
Furthermore, it has been reported that the reduction in
these compressive forces can be reduced by as much as 50%
when utilizing a weight belt. (16,18,19)
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Additional benefits exist with the use
of the weight belts due to IAP. Subjects demonstrated faster
lifting movement (12,13,20) , greater emphasis on hip
extension relative to knee extension (12) , as well as
greater comfort and sense of support. (12,13,17,20,21)
Potential
Hazards of Improper Usage
The use of both weightlifting belts and immobilizing lumbar
braces must be observed in terms of their appropriateness.
The fact that there are benefits to wearing these devices
tends to create the perception that they should be worn at
all times, during any lifting activity. This is a myth that
will only lead to decreased performance and potential
injury.
For instance, the significant
increase in IAP and thus the resulting benefit, has been
shown to be with heavier lifts of the 90% maximum (1RM)
condition. (12) Although during a set of higher repetitions
(10 RM) it is reported that while only 61% of the 1 RM is
utilized (22) , a possible significant effect of increasing
IAP may be considered a cumulative benefit if the last few
repetitions are close to failure. (13,17) It would be easy
to surmise from this information that wearing the weight
belt at all times would be the best insurance policy.
However, electromyographic activity
of the stabilizing musculature is reduced when a weight belt
is worn which could lead to atrophy of the postural muscle
groups. (12,16,23) Injury potential is obviously higher in
muscle tissue that is devoid of the optimal training
stimulus.
Furthermore, lumbar support devices
that increase IAP must be tightened to be effective. High
IAP, however, may impede blood flow back to the heart (12)
as well as significantly raise blood pressure. (24) Wearing
a weight belt at all times would certainly appear
contraindicated when all the criteria are examined.
Recomendations
There has been a great deal of information cited above
regarding lumbar support devices. From these references the
appropriate use of a weight belt or back brace should first
be determined based on the person's objective. The
corset-style back brace is commonly used for immobilization
due to an injury. These are not directly associated with the
concept of stabilization by increasing IAP and therefore
could possibly be worn for an extended period. Anyone
wishing, however, to use a brace of this type should consult
their physician for specific direction. Individuals who are
free from acute or chronic lower back pain may choose a
lumbar support device in order to prevent injury as well as
assist their own musculature for maximal strength
enhancement. In the gym environment the weightlifting belt
should not be worn at all times. The belt should only be
utilized for exercises that involve the spinal erectors
against high resistance i.e. squat and deadlift. (21) The
belt should be loosened after every set and the individual
should breathe between every repetition.
With proper training progression a
person should eventually wean themselves off of the weight
belt (21) and utilize the support device when intensities
reach 80% of the person's 1 RM unless a set of multiple
repetitions is performed to failure. (12) It is imperative,
however, that training at lower intensities continue without
the weightbelt. This will help ensure the natural
stabilization and production of IAP (11).
In the industrial setting, the use
of lumbar devices is controversial. Requiring a lumbar
support device to be worn while on the job can actually be
more of a hindrance than a help unless a training program be
included. The training program should include proper
technique as well as an exercise prescription for
conditioning the body's natural stabilization mechanism.
For occupations such as fire
fighting, the back brace would not be logistically
convenient or biomechanically efficient simply by the nature
of the unpredictable work environment. The most prudent idea
to truly protect this special population would be a
comprehensive hips and trunk stabilization and conditioning
program. Many programs are targeted toward a healthy back
when the coordination of the hips and trunk should be the
ultimate focus. This is not to say that a weight belt should
never be used, but rather considered more of a last resort
where the appropriateness is carefully scrutinized.
References:
1. Perry, I, The
use of external support in the treatment of low back pain.
J. Bone Joint Surg. 52A: 1440-1442, 1070
2. Axelsson P,
Johnson R, Stromqvist B, Effect of lumbar orthosis on
intervertebral mobility. Spine, 17: 678-681; 1992
3. Grew N,
Intra-abdominal pressure response to loads applied to the
torso in normal subjects. Spine, 5: 149-154, 1980
4. Lantz S, Schultz
A, Lumbar spine orthosis wearing: I Restriction of gross
body motion. Spine; 11: 834-837, 1986
5. Lantz S, Schultz
A, Lumbar spine orthosis wearing: II Effect on trunk muscle
myoelectric activity. Spine; 11: 838-842, 1986
6. Norton P, Brown
T, The immobilizing efficiency of back braces. J. Bone Surg;
39: 111-139, 1957
7. Reyna, JR, et.
al., The effect of lumbar belts on isolated lumbar muscle.
Spine; 20, 1: 68-73, 1995
8. Harmen E,
Rosenstein R, Frykman P, Nigro G, Effects of a belt on
intra-abdominal pressure during weight lifting. Med Sci
Sports Exerc; 21: 186-190, 1989
9. Andersson G,
Ortengren R, Nachemson A. Intradiskal pressure,
intra-abdominal pressure, and myoelectric back muscle
activity related to posture and loading. Clin Orthop; 129:
156-164, 1977
10. Davis P, The
use of intra-abdominal pressure in evaluating stresses on
the lumbar spine. Spine; 6: 90-91, 1981
11. Harman E,
Weight training safety: a biomechanical perspective.
Strength and Conditioning; 16: 5: 55-60, 1994
12.Lander J,
Simonton L, Giscoble J, The effectiveness of weight-belts
during the squat exercise. Med Sci Sports Exerc; 22:
117-126, 1990
13. Lander J,
Hundley J, Simonton R, The effectiveness of weight belts
during multiple repetitions of the squat exercise. Med Sci
Sports Exerc; 24: 603-609, 1992
14. McGill S,
Norman R, Sharrat M, The effect of an abdominal belt on
trunk muscle activity and intra-abdominal pressure during
squat lifts. Ergonomics; 33: 147-160, 1990
15. Bartelink DL,
The role of abdominal pressure in relieving the pressure on
the lumbar intervertebral discs. J. Bone Joint Surg; 39B:
718-725, 1957
16. Morris JM,
Lucas DB, Bresler B, Role of the trunk in stability of the
spine. J. Bone Joint Surg; 43A: 327-351, 1961
17. Bourne ND,
Reilly T, Effect of a weightlifting belt on spinal
shrinkage. Br. J. Sp. Med; 25 (4): 1991
18. Eie N, Load
capacity of the low back. J. Oslo City Hosp.; 16: 73-98,
1966
19. Lander JE,
Bates B, DeVita P, Biomechanics of the squat exercise using
s modified center of mass bar. Med Sci Sports Exerc; 18:
469-478, 1986
20. Cappozzo A,
Felici F, Figura F, Gazzani F, Lumbar spine loading during
half-squat exercises. Med Sci Sports Exerc; 17: 613-620,
1985
21. Fagenbaum AD,
Liatos NS, The use and abuse of weightlifting belts.
Strength and Conditioning; 16; 4: 60-62, 1994
22. McDonagh MJN,
Davies CTM, Adaptive response of mammalian skeletal muscle
to exercise with high loads. Eur J Appl Physiol; 52:
139-155, 1984
23. Waters R,
Morris J, Effect of spinal supports on the electrical
activity of muscles of the trunk. J Bone Joint Surg {AM};
52: 51-60, 1970
24. Hunter G,
McQuirk J, Pearman P, Mitrano N, Thomas B, Arrington R, The
effects of a weight training belt on blood pressure during
exercise. J. Appl. Sports Sci. Res.; 3: 13-18, 1989
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