The Truth about Core Training: Part 3
John Gray is a Ph.D. Candidate in Spine Biomechanics at the University of
Waterloo, working with internationally-renowned Spine Biomechanist, Dr.
Stuart McGill, Ph.D. He is also a Certified Kinesiologist with the Ontario
Kinesiology Association, a Certified Strength and Conditioning Specialist
(CSCS) with the National Strength and Conditioning Association, an NCCP
Certified Weightlifting Coach, and the co-owner of First Line
Kinesiologists, Inc.
CB: John, is most low back pain (LBP) related to weak abs?
JRG:
No. Almost never. This is a fitness myth, probably started by some equipment
manufacturers. LBP has so many causes that it is impossible to say this.
CB: How much do these exercises on unstable surfaces contribute to core
strength and endurance?
JRG:
Not at all. Chek and others have popularized the whole "inner unit" issue,
but it is completely unrealistic. You get more ankle work than core work
when training on unstable surfaces. This is a complete extrapolation of
research into an area it was never intended.
CB: Does a healthy person need to put any conscious thought into muscular
control of their TVA (transverse abdominis)? Does an injured person need to
consciously address this muscle?
JRG:
Unless you have an $8000 diagnostic ultrasound unit in your gym, chances are
that you will never be able to do this. The Australians don't even teach
this to physiotherapists without this imaging technology because you need
the visual biofeedback to be able to do it.
Regardless, once you are upright, everything is active (albeit at a low
level ~ 2-3% MVC). During any kind of body movement, the larger superficial
muscles are MUCH more important to spine stability. Hodges is even saying
this nowadays (Paul Hodges, PT, PhD, one of the originators of the
Australian approach).
CB: How much core strength/endurance is enough for athletes? What about for
Joe Deskworker?
JRG:
Impossible to say...Many athletes just participate in their sport and do
very well. Others get crushed by the training program and need more
attention.
There are some standards out there in terms of strength:endurance ratios and
endurance ratios between back extensors, flexors, and lateral flexors, but
they are directed at establishing "safe" norms. It's usually a case by case
issue - if the person is having trouble
with back pain or "weakness", then things need to be done in the program to
address it.
For Joe Deskworker: some people don't exercise at all and still
stay "healthy", or at least don't get back pain. The whole "core" issue is
completely overblown and the “mind/body” crowd is now keeping the hype
alive.
CB: Could you address the common question about people needing to train
their "upper and lower abs"? What type of risk is incurred by doing leg
raises and such that are proposed to train the lower abs?
JGR:
Many people, including trainers and coaches, hold the common belief that you
need different exercises to train the upper and lower sections of the rectus
abdominis (the "Six-Pack" muscle). In fact, years of research experiments in
Dr. McGill’s laboratory have shown that both upper and lower sections of
this muscle are equally as active during ANY exercise requiring flexion. A
few years ago, Dr. McGill published a research paper that clarifies this:
Lehman, GJ & McGill, SM. Quantification of the differences in
electromyographic activity magnitude between the upper and lower portions of
the rectus abdominis muscle during selected trunk exercises. Physical
Therapy. 2001 May;81(5):1096-101.
Abstact available at the following link:
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?
cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11319934
The original "upper/lower abs" idea was based on a research experiment that
jumped to a conclusion because of errors in the methods they used.
Unfortunately, laypeople often mistakenly consider that all published
scientific research is complete truth.
However, to the scientists, new papers are often like single statements in a
long debate. One must first understand the research area to appreciate the
relevance of a single research study. The upper/lower rectus issue is being
popularized in the general media because it supports the fitness industry's
interests for new materials and products. Unfortunately, it doesn't
represent reality.
Now, something that often goes under-appreciated is that the internal
obliques (and lower sections of the external obliques) are very important
for lumbopelvic stability. Quite a lot of work has been done in this area,
and our laboratory measurements fully support these ideas. These muscles are
not used just for twisting movements - they are also particularly active in
movements requiring hip flexion, like kicking or leg lifts. So, although it
is incorrect to refer to upper or lower rectus, we can refer to the "lower"
abs as long as we specifically consider the lower sections of internal and
external obliques, and not rectus abdominis in particular.
CB: What lower-back problems are common to golfers? What should they then
avoid or add in their program, if it is appropriate to recommend anything at
all?
JRG:
Although golfers can experience a large number of sport-related spine
injuries, a common problem is low back pain associated with aggressive
twisting and side-bending motion beyond their normal range of motion. This
is made worse by the fact that most golfers go from being sedentary to this
very ballistic motion.
Keeping generally fit helps most recreational golfers prevent injury, but
walking the course and staying warm is definitely a smart move. Golfers
should be aware of errors in their technique that could increase the
potential for injury, and changing foot placement can sometimes help avoid
trunk rotations into and beyond their end ranges of spine motion.
CB: Finally John, many people state, “I use all of these ‘bad’ training
exercises and techniques and I’ve never had a back problem.” How do you
respond to that?
JRG:
I tell them to be happy they are winning the “survivor” series…for now. It’s
true, some people are capable of handling great physical stresses without
apparent injury, but the basic mechanics of what is happening inside the
body does not change between people.
We have to remember that the risks of certain exercises compared to others
are “relative.” Although it’s impossible to say with complete certainty that
any given exercise WILL injure your back – you now have choices that will
allow you to make better and more informed decisions that will decrease your
risk of developing a back injury in the future.
We also know from biomechanical and rehabilitation research that disc
injuries are caused by specific mechanisms that are reproduced in exercises
that flex the spine under load. So, do you want to train hard, or train
smart?
For people who are still unconvinced, I sometimes also use the analogy that
there are people in their 80s who have smoked their entire lives and never
developed cancer… do you care to try your luck?
If you are interested in more information on this topic, see Dr. Stuart
McGill's books "Low Back Disorders" and "Ultimate Back Fitness and
Performance." Book content and ordering information is available at
www.backfitpro.com.
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