This is intended as a guide and many of the views are based
purely on my opinion and interpretation of research. If you are at all
concerned about using a weightlifting belt then consult a physiotherapist in
person.
An aspect of training
for high level sport can be the use or avoidance of weight lifting belts. With
heavy squats, deadlifts and Olympic lifts becoming more popular with the
introduction of sports such as crossfit and also the recognition of using
weight training to improve performances in other sports such as running and
cycling the foreseen need for weight lifting belts is increasing.
The decision to use a
belt for me until this point was purely based on the opinions and “gym facts”
that are given to me by friends and other athletes. The information given to me
has been extremely varied ranging from it being extremely unsafe to squat
without a weight lifting belt due to the forces that are applied to the spine,
compared to the polar opposite view that weightlifting belts should be avoided
at all costs due production of stability that isn’t created by yourself which
eventually leads to injury. In this blog I hope to review some articles and
paint a clearer picture on how to guide your own decision on the use of a
weightlifting belt.
Firstly a differentiation needs to be made about the type of
belts that are
available. There are primarily 2 different types of belt and there
focus tends to be on different
things. Firstly the Velcro belt, these are generally a synthetic
material and held together by Velcro. Although having the ability to generate
an increased intra-abdominal pressure they have a limit to the amount of force
that can be exerted against them. The focus on the belts is much less about the
potential increase in performance they provide but simply potential injury
prevention.
Powerlifting belts on the other hand are typically heavy duty
and stiff materials that are buckled tight. These in theory increase the internal pressure (intra-abdominal
pressure), more pressure in short results in a greater amount
of stability to lift more weight. The focus is less on safety and more on
performance enhancement.
Next what are the traditional pros and cons that are thrown
around by other trainers?
Some of the belts potential pros are the perceived reduction in chance of
injury (due to increased spinal stability added by the belt). Secondly an increase in performance (as greater weight is moved).
The potential cons can
be that the lower back misses out and becomes less strong as a result (which
may increase the risk of injury) and also an inhibition of the motor learning
of the abdominal muscles in novice lifters as the body may not learn to adapt
correctly to heavy loads without the belt.
Now one of the massive
contradictions in belt use is injury
prevention. Many claim that the belt is used to prevent injuries while
others claim that a benefit that is produced by the belt is completely negated
by the underdevelopment of muscles which leads to injury.
One study by Reddell et al (1992) looked into
the use of belts purely as injury prevention tools for airline baggage handlers
(these are the Velcro kind). The study used 642 participants splitting them into
4 groups: a group receiving the belt
only, a group receiving a 1 h training class only, a group receiving both a
belt and a 1 h training class, and a control group receiving nothing. Two treatment groups
were added which contained participants who discontinued use of the belt prior to the end of an 8-month study
period. The study unfortunately had a poor compliance rate of 58% in wearing
the belts as many found them too hot and irritating. There were no significant differences for total
lumbar injury incident rate, restricted workday case injury incident rate, lost
workdays and restricted workdays rate, and worker's compensation rates between
the groups. This study seems to indicate that the belt showed no great effect on reducing back injuries
when used in baggage handlers. In this study the belt was purely being used as
injury prevention and not for any change in intra-abdominal pressure. The
results are interesting as they suggest no benefits to the belts use but this
is in long term daily use and not gym
specific.
Injury
prevention with the use of belts seems to be based on the development of
intra-abdominal pressure but what is
intra-abdominal pressure? And why is it needed in lifting tasks?
Effectively intra-abdominal pressure is as it
sounds- “Pressure that occurs within the abdominal cavity,” something that
occurs on a day to day basis during activities such as coughing, crying
(hopefully not day to day) and bowel movements. This build up in
intra-abdominal pressure is thought to help stabilise the spine as the force
generated anteriorly to the vertebrae aids in keeping them in a nice neutral
position. This therefore has led to the advice to perform a Valsalva manoeuvre before lifting heavy
weights. The Valsalva manoeuvre is an inhalation of breath followed by an
attempted exhalation against a closed airway, thus causing an increase in
intra-abdominal pressure.
This increase in intra-abdominal pressure is one of the main perceived
benefits of lifting belts as in theory it may help keep the spine in a neutral position under a heavier load due to an
increase in intra-abdominal pressure. This being said a study by Miyamoto et al
(1996) showed that there was no
difference in intra-abdominal pressure when a belt was worn during
isometric maximal exertions or when the Valsalva manoeuvre was performed
compared to no belt being worn. Instead the only significant difference found
was an increase in intra-muscular
pressure of lumbar erector spinae when the belt was worn. This study would
suggest that belts do not help to increase intra-abdominal pressure when
lifting. Despite this the study only had 7 male participants and the lifts were
static and not dynamic. The same researchers did perform a questionnaire on
Japanese weightlifters who unanimously reported the feeling of increased spinal stiffness when wearing a belt.
Another study performed by Kingma et al (2006) looked at the use of
weightlifting belts when experienced weightlifters performed a squat with a
mixture of belt/ no belt and Valsalva/ No Valsalva manoeuvre. This study found
that a greater amount of spinal
stability was produced when a weightlifting belt was combined with the
Valsalva manoeuvre (reducing compression forces by roughly 10%) but what is
interesting is that this increase in spinal stability was not due to an increase intra-abdominal pressure but instead caused by an extension moment that the belt
generated. As the moment travelled in a different direction to the force of
the weight a reduction in spinal compression was achieved. Kingma et al (2006)
therefore would suggest that the use of a weightlifting
belt can reduce spinal compression by around 10% which may reduce the
chance of injury. The research from this study is confounded in previous research by Bourne and Reilly (1991) that
showed that belt use decreased the
amount of spinal shrinkage that occurred after weight training and also decreased perceived discomfort.
Looking at the evidence above there appears to be some backing for the
use of weightlifting belts. Although not appearing to massively increase
intra-abdominal pressure in some studies it has shown itself to decrease spinal
compression and decrease perceived discomfort when worn. Therefore the pros of
reduced risk of injury may be argued due to this reduction in spinal
compression. Secondly the qualitative evidence seems to suggest performance
enhancement.
Reading the research it is clear that intra-abdominal pressure is
desirable in combination with a neutral spinal position. This brings us to the core (an area that
many people feel gets neglected when a belt is used.) core muscles play a large
role in spinal stability during dynamic loading condition such as a weighted
squat or deadlift , the oblique’s and
rectus abdominals are active BUT both of these muscles also cause flexion of the spine, this in
turn increases spinal compression
both directly (due to the flexion
moment) and indirectly due to the
counter-activation of back extensors such as erector spinae (McGill &
Norman, 1987). The only muscles capable of increasing
intra-abdominal pressure and not creating a flexion/extension moment are
transverse abdominis and the diaphragm. A weak transverse abdominis is
extremely common in low back pain patients and looking at the facts you can see
why. If you are overactive in muscles that produce extension/flexion moments
then spinal compression will only increase.
Unfortunately I am not able to find research that shows the amount of
activation present in trans-abs when a belt is used and when it is not. This is
something that would be very interesting as it is likely that the trans-abs may
switch off when a belt is used as the increased stability is generated artificially.
If you do have weak trans abs then you will as a result have to incur a greater
spinal compression force when dynamic loading is applied.
As always in sport medicine the picture is not very clear. My opinion on
the matter is similar to that of most of the powerlifting community. Belts are
capable of decreasing spinal compression and can be a helpful tool when trying to lift heavy weights BUT correct contraction of trans-abs and use of
the diaphragm is essential when training to lift heavy. Therefore I would
not suggest a 24/7 reliance on belt use but instead its use as an occasional
training aid.
I would love to hear any opinions on the matter or any feedback on the
writing of this blog post.
Works Cited
Bourne, N. & Reilly, D., 1991. Effect of a
weightlifting belt on spinal shrinkage. British Journal of Sports Medicine,
25(4), pp. 209-212.
Kingma, I. et
al., 2006. Effect of stiff lifting belt on spine compression during lifting. SPine,
31(22), pp. 833-839.
McGill, S.
& Norman, R., 1987. Reassement of the role of intra-abdominal pressrure in
spinal compression. Ergonomics, 30(1), pp. 565-88.
Miyamoto, K.,
Iinuma, N. & Kikuike, A., 1992. Biomechanics of lumbar support belts (Part
1: A survey questionaire for weightlifters in japan). Records of Tokai
Association of Sports Injuries, pp. 36-39.
Miyamoto, K.
et al., 1999. Effects of abdominal belts on intra-abdominal pressure,
intra-muscular pressure in erector spinae muscles and myolectrical activities
of trunk muscles. Clinical Biomechanics, Volume 14, pp. 79-87.
Reddell, C.,
Congleton, J., Huchingson, R. & Montgomery, J., 1992. An evaluation of a
weightlifting belt and back injurt prevention training class for airline
baggage handlers. Applied Ergonomic, 23(5), pp. 319-29.
