So if I jump from the floor, you can determine
how many centimeters I elevate from the floor.
It's an absolute measure. For DMG, it does not.
Why? Because it depends on the specific location
near the muscle where I put DMG. So if I have
a... region of my skin where there is a little
bit of more dead skin the resistance of my skin
will be higher this will affect the reading of
the emg so it's a not absolute measurement so
we take the maximum amplitude of potential that
we see elicited within the leaf in the condition
of using straps and we compare it to the maximum
potential that is elicited when you don't use
it not using straw we calculate the difference
Hi, Francesco. It's my pleasure to have you on
Evidence Strong Show. If you could briefly introduce
yourself. Thank you, Alex. It's my pleasure to
be here today. Thank you for the invitation.
So my name is Francesco Travascio and I am Associate
Professor at College of Engineering at the University
of Miami. I've been conducting research in the
field of biomechanics for the past almost 20
years. And one of my interests, obviously, is
sports biomechanics. And well, my preferred sport
is weightlifting. So today we are going to talk
about weightlifting. Yes. So the study we'll
be talking about is about the use of straps in
snatch and it involves measuring muscle activation.
These studies are super, super rare. There are
maybe three, four coming a year in weightlifting
and with EMG and there are reasons for that.
So let's talk about it. Why these studies are
so hard? Well, they are hard to my, I mean, anecdotal
evidence, right? My personal experience. This
is because generally... the handling of the EMGs
is a quite delicate typopic. It's quite delicate
as a type of sensor. And it is routinely used
for analysis on nerve conduction and muscular
activation in a clinical setting, in hospitals
or in clinics. It's less used in the case of
sports application, especially when the movements
are very explosive, like in weightlifting. What
we are trying to measure is the muscular contraction.
And obviously, the muscular contraction in weightlifting
is very impulsive and explosive. And so this
creates a number of problems in terms, very technical
problems in terms of adhesion of the device that
we are attaching to the muscles to measure. So
I don't know if you, I mean, I can digress a
little bit on the device, how the device is,
but essentially it's a little box that probably
may weigh a few grams, like 30, 40 grams, that
contains a receiver. And this receiver sends
to our wireless. apparatus, the signal that is
read by electrodes that are applied on the skin
of the subject. Essentially, the way it works
is whenever we contract a muscle, or we want
to contract a muscle, we send a signal to our
neurons through the muscular fibers. And we fire
what we call an action potential, which is an
electrical impulse, if you want to put it in
layman terms. And this activates the control
motor unit that changes the electrical potential
of the cells. of the muscular cells. And this
change in electrical potential produces a spike
into the voltage that we did, the electrical
potential that we can read on the skin in proximity
of the muscle that is contracted. So by looking
at how large is this electrical potential, we
understand how many cells contracted and contributed
to this electrical potential. The larger is the
amplitude of this electrical potential means
more cells are participating, more muscular activation
is occurring in that specific time frame. by
looking at different... exercises or conditions
and comparing the electrical potentials with
the amplitude of these electrical potentials
associated to these different activities, we
can determine whether or not there was more muscle
activation in doing a certain type of exercise
rather than another. So this is a very simple
to say, quite complicated actually in doing it
in practical terms, because obviously these devices,
like I said, they're applied on the body and
the electrodes that we applied. to receive the
signal, have some sort of adhesive gel. However,
you know, when you do sports, you tend to sweat,
and obviously the sweat causes problems of adhesion.
On top of it, we have these explosive movements
that contract the muscles and move the body with
very high accelerations. And this essentially
represents a big problem in having these sensors
to be attached to the human body while they are
doing these activities. And we learned in a very
hard way because in our... For our first pilot
experiments, we were seeing these sensors flying
in the training hall everywhere. And they're
also very expensive. So we were very concerned.
So we started to learn, you know, from our mistakes
and try to find mitigations. So one of the mitigations
was actually wrapping around the muscle with
gauzes. Put the gauzes not too tight, obviously,
but tight enough not to prevent, you know, the
departure of these devices using athletic tape.
And we used to... put our athletes during the
training in front of big plants so all the all
the sweat could dry as much as possible try to
minimize all the possible effects that would
cause this loss of sensors it was pretty funny
but we had a lot of fun we had a lot of fun all
right so that's EMG in general now in this study
what did you try to find out and how did you
set up the experiments yeah so what we were trying
to we know that using the straps by empirical
evidence anecdotal evidence or even by other
studies conducted in other weightlifting sports
have certain benefits for instance there is a
lot written on the use of straps in deadlift
right so the first thing certainly the fact that
we're using straps means that we don't have to
grip so hard at the barbell so we can spare the
use of our forearm muscles and this turns out
to be an advantage when you want to deload your
forearm muscles and studies on deadlift have
shown that actually Sparing these muscles allows
you focusing more on using other muscles, like
muscles of the back or the entire posterior chain.
Unfortunately, nothing is, there is not very
much done on the use of straps. So we were very
interested for two reasons. One, because for
once, nobody, there is this anecdotal, I mean,
there is this common sense, right, type of logic.
If I use the straps, I'm going to deload the
forearm, so it's going to be beneficial for my
forearms in a way. And maybe I can focus more
on activating other muscles. other patterns of
motion, but there was no quantitative evidence.
So this motivated us to undertake this study.
And our hypothesis was that the use of straps
from one side could reduce the muscular activation
in the forearms, and from the other side could
also promote enhanced activation of the posterior
chain. Could you tell us who did you recruit
for the study? So who were the participants?
Yeah, so this was another challenge because obviously,
you know, you have to find people who are willing
to, very brave people who love so much the sport
and love so much the science that are willing
to go through all this. So essentially the problem
is that one of the tricky parts of the EMGs,
this is very important to understand why it's
difficult to find these people. One of the tricky
parts of the EMGs is that they read this electrical
potential, right? That is developed by our body
and our muscle. But this electrical potential
is affected by the electrical resistance of the
skin and the muscles and the... fact layers in
that specific region where you apply the APG.
This means that for the same contraction on my
bicep, I may read different electrical potentials
if I move over a couple of centimeters away the
electrode. So if I want to have a real comparative
measurement when I use the straps or when I don't
use the straps, once I apply the electrodes,
I have to keep the electrodes always in the same
position when I use the straps or not. So we
have to require, we couldn't call that subjects
on another day or one day you do it. straps on
the other day you do it without straps it had
to be done all at once so the athletes were supposed
to go through a run from a 60 percent up to a
85 percent of lifting sequences of lifting without
straps and then repeat it again with the straps
or in a randomized order some of them started
with straps some of them without straps so in
reality it's very disruptive of their lifting
routine so we had problems and finally those
athletes that were preparing competitions obviously
had more problems in participating because that
would have been very disruptive for their training
routine. Fortunately, we found a very sufficient
large number of athletes from a local gym, Team
Soul Miami, amazing people who really wanted
to go through all this ordeal. And we actually
were able to complete the study. We used the
population of sub -elite athletes, athletes that
had competed in regional and national level.
The requirement was that they would train at
least three days per week. Obviously, all of
them trained five days a week. And obviously,
they didn't have any muscular injury that prevented
them from executing the movement in the way it's
supposed to be executed. All right. How many
did you have, the participants? How many? We
had a total of 12 participants, which... gave
us enough power for our statistical analysis.
And they were all males, I think, were they?
Okay, 12 males. All right, now, this is an EMG
study, so we are measuring muscle activation.
Do you want to say a little bit more about what
kind of outputs did you get in your data? You
know, like when we test, for example, because
this is something my viewers will be familiar
with, testing jump, for example. So if you do
it on force places, you will have forces. You
can calculate, you can see velocity, you can
see jump height. So these would be the variables
people would be more familiar with. With EMG,
what do you get? What do you work with? Yeah,
so again, the EMGs are very particular. So like
I said, because we are looking at the muscular
contraction that translates into electrical potentials,
we are looking at the peak of these electrical
potentials that are elicited when there is a
muscular contraction. Okay, so... What we are
actually looking at in a quantity that is a voltage
that is in millivolts, generally, is the order
of magnitude. And like I said before, the measure
itself is not an absolute measure. So if I jump
from the floor, you can determine how many centimeters
I elevate from the floor. It's an absolute measure.
For the EMG, it does not. Why? Because it depends
on the specific location near the muscle where
I put EMG. So if I have a... region of my skin
where there is a little bit more dead skin, the
resistance of my skin will be higher. This will
affect the reading of the EMG. So it's a not
absolute measurement. So we take the maximum
amplitude of potential that we see elicited within
the leaf in the condition of using straps, and
we compare it to the maximum potential that is
elicited when you don't use it, not using straps.
We calculate the difference. And you do it per
muscle? Per all the muscles that we study. So
obviously, you know, you would like to measure
everything if possible, right? But again, you
know, we are in the real world. Like I said,
it's quite cumbersome and it's also quite uncomfortable
for the athletes. So what we had to do is to
measure only those muscles on the dominant side.
So if the athlete was right -handed, we measure
only eight muscles on the right side or on the
left side if the person was left -handed. The
muscles that we studied were flexors. So we had
essentially muscles from the upper limbs, shoulder,
the back, and some of the posterior chain. Those
that are in the back are obviously even more
challenging because people tended to sweat on
the back and it was very difficult to wrap all
around the chest these gauzes. Like I said, these
were the challenges that we faced. And yeah.
So we compared essentially for each muscle, we
compared these electrical potentials. Obviously,
as we know, snatch has several phases. They start
with the first pull and the second pull and then
the catch. and then the squat, we monitored the
activation of these muscles throughout all these
phases. But obviously, we were more interested
into the first initial phases of pull because
it's where all the major muscle contractions
occur and where actually the straps seem to have,
we hypothesized that the straps can have an effect.
Obviously, there is not much effect the strap
can have in the catch position or in the overhead
squat. It's just that they are not meant to improve
that part. They are meant to improve the pace.
So that's why we focus mostly on the phase of
pulling. Awesome. So what you get at the end
is the trace of the muscle activation. So the
potentials. Yes. So what you get is actually
the trend of activation, spikes of potential
throughout all the entire movement. And together
with the DMGs, we had cameras that at the same
time monitored the movement of the athletes.
So we could determine when a certain type of...
spike occurred and that spike was associated
to the first pool or the second pool or any other
phase of the leak. So we separated, our analysis
was comparing with or without the straps, each
muscle in each phase of the leak with the major
focus on the first two phases of the leak. That's
a lot of work. And let's not forget that each
signal has to be processed and filtered and so
on. Yeah, I guess that for an engineer. because
we executed this with my PhD students in engineering.
This was the signal processing was not probably
the hardest part of it. Now, I mean, although
you want to use EMGs, I used to say you want
to use EMGs. EMGs are nice. They can give you
a lot of information, but you want to use EMGs
only when you definitely like to use EMGs because
there is no other way, right? If you can try
to bypass, I'm happy to do that. We wrapped up
twice. from 60 % to 80 % with starting. I mean,
we had some sort of a mixed progression of stepwise
and linear progression of the weights. So having
more repetitions at lower percentages and then
executing singles, three singles at 80 % without
straps and three singles at 80 % with straps.
Are we ready for the results? Sure. So we found
very interesting results. We found that we had
made a significant decrease in the mass. activation
of the forearms up in between 15 to 20 % less
activation when using the strikes. This also
reflected a little bit in the lesser activation
of the bisects, although those were very, very
small, around 5%. But interestingly enough, we
saw an increase in the activation of the deltoid
and the lateral sinus dorsi. They probably had
the largest increase of activation when using
the strikes. And in the upper body. And even
more interestingly, we found an increase in the
activation of the quad on the vastus lateralis
that went up to 40 % in some cases. 40 % more
activating when using lifting straps as compared
to non -using lifting straps. So in a way, we
sort of validated our hypothesis that the use
of lifting straps not only benefits the deload
of the forearms, but also helps engage more all
the other muscles that are involved into the
exercise. And I think that probably, I would
say that the most important message to me, in
my opinion, is that the use of lifting or the
use of straps should be recommended in general
for general use in strength and condition. So
we know that Olympic lifts are also used in other
sports for strength and conditioning. And in
other sports, athletes may not need to gain the
level of proficiency in technique like an Olympic
weightlifter. And they generally focus more on
pulls rather than execution. in the entire movement.
Or maybe they power it. They power snatch. So
at that point, I think that it would be very
beneficial for them. They could get more out
of the exercise if they would use straps. Because
they definitely don't have to train their grip
strength like a weightlifter would have to. But
surely they have to train their lower lips and
their back. And that's just the observation,
but when you use straps, you may load heavier,
which means higher weight for the exercise. athlete
who is doing the exercise. So you can load athletes
more effectively using straps because the grip
is not restricting how much they can use. Absolutely.
There are several studies that have shown this
is in deadlift that obviously by releasing, by
not being bound on the way on the amount you
lift by your grip strength, you can actually
lift more. And this is also the reason why straps
are not allowed into competitions of weightlifting,
right? Because we know that they have actually
beneficial effect in giving you the opportunity.
to lift higher weights. But now we measure, right?
Now we have a quantitative data to associate
to this probably common sense, obvious or empirical
observation. You know what goes through my head?
How much more could I lift in the snatch if I
would be using straps? That would be a very interesting
question. I have no idea how much, but it would
be interesting to test. It would be very interesting.
Because you say, I may be guessing now, but latissimus
dorsi, you said around up to 20%. So this is
for that? It was probably more the latissimus
dorsi. I think it was probably up to, in some
cases, up to 30%. If the muscle activation is
changed so much for some of the muscles, because
30 % is huge, huge change, how it will influence
the loading? And because the patterns of activation
are changed, will the technique have to change?
Will the very professional... weightlifters,
so the elite who can do the most without straps,
will they struggle to do straps or they can do
more? I don't know. Well, I've seen some YouTube
videos of elite weightlifters that when they
use the straps, they do something really impressive.
They go to weights that are really, really impressive.
What really struck me is that we had cases in
which the contraction of the vastus lateralis
went up to 40%. more. I mean, we're talking about
a major effect. a major effect. But I mean, this
did not happen in all the subjects. Oh, interesting.
I think you need to run another study, Francesco.
Oh, absolutely. You're giving me a lot of ideas.
And yes, certainly. We are very interested in
conducting studies in sports biomechanics. And
obviously, weightlifting is my passion. And my
students, I'm trying to involve more and more
my students also in the practice of the sport.
I'm bringing them to the dark side, yeah? Yes,
to the dark side. Excellent. Well, going back
to the... To my question with how much more the
lifter is able to lift with the straps. If we
would know how much, then we can calculate, okay,
if I want this snatch on the platform, this is
where I would have to go to with straps or try
to overload, I don't know, face by face or, you
know, different methods. Very good question for
a coach, right? And generally, when I personally,
when I've trained, I always pull with straps
all the time. I may use straps during, you know,
my routine, but only when I am quite far away
from competition. So when I'm getting closer
to competitions, I rather not using them because
I understand that there is, there might be a
change in the technique or the way you approach
the lift. And also you want to still keep your,
in a way, your grip straight, in a way. So it's
definitely an excellent question for a coach.
I have one more question about EMG and weight
classes. So will the EMG signal or the reading
differ? depending on how much fat tissue the
athlete will have. Because lower weight class
athletes tend to be a little bit leaner than
super heavy athletes, for example, where there's
no limit on the weight, body weight. So they
usually will hold a little bit more fat tissue
because they can. Again, I mean, the fat tissue
has an effect on the overall impedance, the electrical
resistance, if you want, in many elements of
your body. So obviously include... in a fat layer
may change in comparison the amplitude of the
potential but again we have to remember that
the measurement of an EMG is not an absolute
measure okay so we have always to compare to
something so in this particular case of this
study we compared the same exercise executed
with a garment and not a garment okay if I want
to just study what is the activation of a muscle
for doing snatch in general without comparing
with anything obviously my reading of the electrical
potential this by itself doesn't mean anything
again because it's the part issue the way you
apply so what we generally do as a comparison
we calculate the maximum voluntary contraction
of the muscle which is a baseline measurement
essentially we have techniques to stimulate the
muscle the specific muscle that we want to target
we want to monitor to its maximum maximum contraction
at this maximum contraction we read the potential
and this electrical potential would be the baseline
would be the maximum effort that you can possibly
put into the contraction of the muscle. Then
we execute the exercise and we read another electrical
potential. And then we refer this electrical
potential to its mass. So we know that during
that exercise, I used 60%, 70%, 90 % of my maximum
capability of contracting that muscle. So if
we are looking at weight classes, yes, there
is a difference in body composition. That's for
sure. That's for sure. It's undeniable. Does
this affect the reading of the EMG? Not really,
because it's a relative measurement. We always...
have an internal comparison. Then it depends,
it boils down to the sensitivity of your EMG,
if it's capable of capturing that potential.
And generally they are used even with large body
mass index people. Pretty sensitive. Yes. Let's
maybe try to bring it all together. So two, three
points, maybe what you want coaches to get out
of this study. Main points. Well, I would say
that in the first place, we showed with quantitative
data that using liquid straps is a beneficial.
effect on deloading the forearms. So it can be
indicated, specifically indicated, when we have
problems of fatigue, for instance, for the forearms.
The second point that we found was that, obviously,
together with the deloading of the forearms,
the use of straps also have a beneficial effect
in increasing the activation of the muscles of
the back and the lower ribs. So in view of building
a program of strength and conditioning for the
athlete, whether the athlete is a weightlifter
or an athlete... of a different specialty it
may be could be an option the use of the straps
in order to enhance the muscle attraction but
obviously we always the other point is last point
probably is we always have to keep in mind that
weightlifting as a sport is done at a competitive
level is done without straps so we cannot abuse
all right at some point we have to go back to
you know the regular weight excellent okay two
more questions to finish the first one is which
is your favorite lift that's a tough question
because it's always love and date you know it
depends on my performances are very alternating.
So I would say that now I would say that definitely
snatch is my favorite lift. I think in general
it's my favorite. Are you asking for the lift
or the lifter? The lift, yeah, yeah. Which one
is it? Yes, I think that the snatch is probably
the most representative type of lift of weightlifting.
It really encompasses the explosiveness, but
also the mobility, the capability of a person
to the agility and the mobility of a person.
And also if you want the grace of a person. in
the movements. It's fascinating. It is. It's
very well executed. It's really fascinating.
Do you have your favorite list there? Oh, many.
But since probably we are talking about snatch,
I have to say that I am very, I always fall in
love with the way Alexey Toropty snatches. He
is extremely graceful and powerful at the same
time. And his technique is just, I really hypnotize
me when I see him. Okay, last question is if
people want to see what you are. Up to what your
research is at the moment, where should they
go online? Okay. So we have our X account with
all our updates and the handler, the analyst,
Biomag with capital B and with an H again, underscore
capital U, capital M as University of Miami.
Awesome. And then you can see all our updates
and you also have the links to our, to the website
of our lab. That's amazing. Thank you so much,
Francesco. was a pleasure my pleasure bye