WEBVTT 00:00:00.000 --> 00:00:02.339 So if I jump from the floor, you can determine 00:00:02.339 --> 00:00:05.160 how many centimeters I elevate from the floor. 00:00:05.320 --> 00:00:07.240 It's an absolute measure. For DMG, it does not. 00:00:07.320 --> 00:00:09.859 Why? Because it depends on the specific location 00:00:09.859 --> 00:00:13.119 near the muscle where I put DMG. So if I have 00:00:13.119 --> 00:00:15.320 a... region of my skin where there is a little 00:00:15.320 --> 00:00:18.219 bit of more dead skin the resistance of my skin 00:00:18.219 --> 00:00:20.440 will be higher this will affect the reading of 00:00:20.440 --> 00:00:22.719 the emg so it's a not absolute measurement so 00:00:22.719 --> 00:00:26.399 we take the maximum amplitude of potential that 00:00:26.399 --> 00:00:29.679 we see elicited within the leaf in the condition 00:00:29.679 --> 00:00:32.899 of using straps and we compare it to the maximum 00:00:32.899 --> 00:00:35.280 potential that is elicited when you don't use 00:00:35.280 --> 00:00:37.520 it not using straw we calculate the difference 00:00:39.710 --> 00:00:41.929 Hi, Francesco. It's my pleasure to have you on 00:00:41.929 --> 00:00:44.369 Evidence Strong Show. If you could briefly introduce 00:00:44.369 --> 00:00:46.549 yourself. Thank you, Alex. It's my pleasure to 00:00:46.549 --> 00:00:48.369 be here today. Thank you for the invitation. 00:00:48.789 --> 00:00:51.229 So my name is Francesco Travascio and I am Associate 00:00:51.229 --> 00:00:53.530 Professor at College of Engineering at the University 00:00:53.530 --> 00:00:56.189 of Miami. I've been conducting research in the 00:00:56.189 --> 00:00:59.289 field of biomechanics for the past almost 20 00:00:59.289 --> 00:01:02.070 years. And one of my interests, obviously, is 00:01:02.070 --> 00:01:05.890 sports biomechanics. And well, my preferred sport 00:01:05.890 --> 00:01:08.170 is weightlifting. So today we are going to talk 00:01:08.170 --> 00:01:11.329 about weightlifting. Yes. So the study we'll 00:01:11.329 --> 00:01:15.170 be talking about is about the use of straps in 00:01:15.170 --> 00:01:18.489 snatch and it involves measuring muscle activation. 00:01:18.870 --> 00:01:21.349 These studies are super, super rare. There are 00:01:21.349 --> 00:01:24.129 maybe three, four coming a year in weightlifting 00:01:24.129 --> 00:01:26.750 and with EMG and there are reasons for that. 00:01:26.849 --> 00:01:29.489 So let's talk about it. Why these studies are 00:01:29.489 --> 00:01:33.890 so hard? Well, they are hard to my, I mean, anecdotal 00:01:33.890 --> 00:01:37.290 evidence, right? My personal experience. This 00:01:37.290 --> 00:01:39.879 is because generally... the handling of the EMGs 00:01:39.879 --> 00:01:43.120 is a quite delicate typopic. It's quite delicate 00:01:43.120 --> 00:01:46.879 as a type of sensor. And it is routinely used 00:01:46.879 --> 00:01:49.939 for analysis on nerve conduction and muscular 00:01:49.939 --> 00:01:52.799 activation in a clinical setting, in hospitals 00:01:52.799 --> 00:01:56.819 or in clinics. It's less used in the case of 00:01:56.819 --> 00:01:59.920 sports application, especially when the movements 00:01:59.920 --> 00:02:02.060 are very explosive, like in weightlifting. What 00:02:02.060 --> 00:02:04.739 we are trying to measure is the muscular contraction. 00:02:04.739 --> 00:02:08.539 And obviously, the muscular contraction in weightlifting 00:02:08.539 --> 00:02:12.099 is very impulsive and explosive. And so this 00:02:12.099 --> 00:02:15.199 creates a number of problems in terms, very technical 00:02:15.199 --> 00:02:18.520 problems in terms of adhesion of the device that 00:02:18.520 --> 00:02:22.020 we are attaching to the muscles to measure. So 00:02:22.020 --> 00:02:24.460 I don't know if you, I mean, I can digress a 00:02:24.460 --> 00:02:26.199 little bit on the device, how the device is, 00:02:26.340 --> 00:02:29.259 but essentially it's a little box that probably 00:02:29.259 --> 00:02:32.460 may weigh a few grams, like 30, 40 grams, that 00:02:32.460 --> 00:02:34.960 contains a receiver. And this receiver sends 00:02:34.960 --> 00:02:38.560 to our wireless. apparatus, the signal that is 00:02:38.560 --> 00:02:41.620 read by electrodes that are applied on the skin 00:02:41.620 --> 00:02:44.479 of the subject. Essentially, the way it works 00:02:44.479 --> 00:02:47.439 is whenever we contract a muscle, or we want 00:02:47.439 --> 00:02:49.539 to contract a muscle, we send a signal to our 00:02:49.539 --> 00:02:53.599 neurons through the muscular fibers. And we fire 00:02:53.599 --> 00:02:56.319 what we call an action potential, which is an 00:02:56.319 --> 00:02:58.080 electrical impulse, if you want to put it in 00:02:58.080 --> 00:03:01.240 layman terms. And this activates the control 00:03:01.240 --> 00:03:04.080 motor unit that changes the electrical potential 00:03:04.080 --> 00:03:07.569 of the cells. of the muscular cells. And this 00:03:07.569 --> 00:03:10.610 change in electrical potential produces a spike 00:03:10.610 --> 00:03:13.629 into the voltage that we did, the electrical 00:03:13.629 --> 00:03:16.370 potential that we can read on the skin in proximity 00:03:16.370 --> 00:03:19.030 of the muscle that is contracted. So by looking 00:03:19.030 --> 00:03:22.169 at how large is this electrical potential, we 00:03:22.169 --> 00:03:25.449 understand how many cells contracted and contributed 00:03:25.449 --> 00:03:27.830 to this electrical potential. The larger is the 00:03:27.830 --> 00:03:29.509 amplitude of this electrical potential means 00:03:29.509 --> 00:03:32.229 more cells are participating, more muscular activation 00:03:32.229 --> 00:03:35.610 is occurring in that specific time frame. by 00:03:35.610 --> 00:03:39.099 looking at different... exercises or conditions 00:03:39.099 --> 00:03:42.060 and comparing the electrical potentials with 00:03:42.060 --> 00:03:44.240 the amplitude of these electrical potentials 00:03:44.240 --> 00:03:46.819 associated to these different activities, we 00:03:46.819 --> 00:03:49.840 can determine whether or not there was more muscle 00:03:49.840 --> 00:03:51.979 activation in doing a certain type of exercise 00:03:51.979 --> 00:03:54.900 rather than another. So this is a very simple 00:03:54.900 --> 00:03:58.819 to say, quite complicated actually in doing it 00:03:58.819 --> 00:04:02.139 in practical terms, because obviously these devices, 00:04:02.139 --> 00:04:04.780 like I said, they're applied on the body and 00:04:04.780 --> 00:04:07.780 the electrodes that we applied. to receive the 00:04:07.780 --> 00:04:10.580 signal, have some sort of adhesive gel. However, 00:04:10.979 --> 00:04:14.219 you know, when you do sports, you tend to sweat, 00:04:14.360 --> 00:04:17.399 and obviously the sweat causes problems of adhesion. 00:04:17.540 --> 00:04:19.839 On top of it, we have these explosive movements 00:04:19.839 --> 00:04:22.399 that contract the muscles and move the body with 00:04:22.399 --> 00:04:25.360 very high accelerations. And this essentially 00:04:25.360 --> 00:04:29.180 represents a big problem in having these sensors 00:04:29.180 --> 00:04:31.879 to be attached to the human body while they are 00:04:31.879 --> 00:04:34.560 doing these activities. And we learned in a very 00:04:34.560 --> 00:04:37.389 hard way because in our... For our first pilot 00:04:37.389 --> 00:04:40.290 experiments, we were seeing these sensors flying 00:04:40.290 --> 00:04:42.110 in the training hall everywhere. And they're 00:04:42.110 --> 00:04:44.550 also very expensive. So we were very concerned. 00:04:44.730 --> 00:04:48.129 So we started to learn, you know, from our mistakes 00:04:48.129 --> 00:04:52.050 and try to find mitigations. So one of the mitigations 00:04:52.050 --> 00:04:54.949 was actually wrapping around the muscle with 00:04:54.949 --> 00:04:57.930 gauzes. Put the gauzes not too tight, obviously, 00:04:58.129 --> 00:05:00.209 but tight enough not to prevent, you know, the 00:05:00.209 --> 00:05:03.970 departure of these devices using athletic tape. 00:05:04.149 --> 00:05:06.990 And we used to... put our athletes during the 00:05:06.990 --> 00:05:10.329 training in front of big plants so all the all 00:05:10.329 --> 00:05:13.189 the sweat could dry as much as possible try to 00:05:13.189 --> 00:05:15.389 minimize all the possible effects that would 00:05:15.389 --> 00:05:18.350 cause this loss of sensors it was pretty funny 00:05:18.350 --> 00:05:20.509 but we had a lot of fun we had a lot of fun all 00:05:20.509 --> 00:05:24.730 right so that's EMG in general now in this study 00:05:24.730 --> 00:05:27.829 what did you try to find out and how did you 00:05:27.829 --> 00:05:30.689 set up the experiments yeah so what we were trying 00:05:30.689 --> 00:05:33.949 to we know that using the straps by empirical 00:05:33.949 --> 00:05:37.149 evidence anecdotal evidence or even by other 00:05:37.149 --> 00:05:39.589 studies conducted in other weightlifting sports 00:05:39.589 --> 00:05:42.269 have certain benefits for instance there is a 00:05:42.269 --> 00:05:44.750 lot written on the use of straps in deadlift 00:05:44.750 --> 00:05:47.129 right so the first thing certainly the fact that 00:05:47.129 --> 00:05:49.490 we're using straps means that we don't have to 00:05:49.490 --> 00:05:52.550 grip so hard at the barbell so we can spare the 00:05:52.550 --> 00:05:56.230 use of our forearm muscles and this turns out 00:05:56.230 --> 00:05:59.310 to be an advantage when you want to deload your 00:05:59.310 --> 00:06:02.629 forearm muscles and studies on deadlift have 00:06:02.629 --> 00:06:05.540 shown that actually Sparing these muscles allows 00:06:05.540 --> 00:06:08.920 you focusing more on using other muscles, like 00:06:08.920 --> 00:06:10.939 muscles of the back or the entire posterior chain. 00:06:11.139 --> 00:06:14.620 Unfortunately, nothing is, there is not very 00:06:14.620 --> 00:06:17.379 much done on the use of straps. So we were very 00:06:17.379 --> 00:06:19.420 interested for two reasons. One, because for 00:06:19.420 --> 00:06:22.699 once, nobody, there is this anecdotal, I mean, 00:06:22.720 --> 00:06:25.220 there is this common sense, right, type of logic. 00:06:25.300 --> 00:06:27.540 If I use the straps, I'm going to deload the 00:06:27.540 --> 00:06:29.560 forearm, so it's going to be beneficial for my 00:06:29.560 --> 00:06:31.759 forearms in a way. And maybe I can focus more 00:06:31.759 --> 00:06:33.879 on activating other muscles. other patterns of 00:06:33.879 --> 00:06:37.000 motion, but there was no quantitative evidence. 00:06:37.300 --> 00:06:39.839 So this motivated us to undertake this study. 00:06:39.980 --> 00:06:43.279 And our hypothesis was that the use of straps 00:06:43.279 --> 00:06:47.160 from one side could reduce the muscular activation 00:06:47.160 --> 00:06:49.620 in the forearms, and from the other side could 00:06:49.620 --> 00:06:52.959 also promote enhanced activation of the posterior 00:06:52.959 --> 00:06:54.959 chain. Could you tell us who did you recruit 00:06:54.959 --> 00:06:57.600 for the study? So who were the participants? 00:06:58.180 --> 00:07:01.120 Yeah, so this was another challenge because obviously, 00:07:01.439 --> 00:07:03.519 you know, you have to find people who are willing 00:07:03.519 --> 00:07:06.680 to, very brave people who love so much the sport 00:07:06.680 --> 00:07:08.660 and love so much the science that are willing 00:07:08.660 --> 00:07:11.560 to go through all this. So essentially the problem 00:07:11.560 --> 00:07:14.819 is that one of the tricky parts of the EMGs, 00:07:14.959 --> 00:07:16.639 this is very important to understand why it's 00:07:16.639 --> 00:07:18.600 difficult to find these people. One of the tricky 00:07:18.600 --> 00:07:20.939 parts of the EMGs is that they read this electrical 00:07:20.939 --> 00:07:23.899 potential, right? That is developed by our body 00:07:23.899 --> 00:07:25.939 and our muscle. But this electrical potential 00:07:25.939 --> 00:07:29.959 is affected by the electrical resistance of the 00:07:29.959 --> 00:07:32.389 skin and the muscles and the... fact layers in 00:07:32.389 --> 00:07:34.610 that specific region where you apply the APG. 00:07:34.709 --> 00:07:37.009 This means that for the same contraction on my 00:07:37.009 --> 00:07:39.970 bicep, I may read different electrical potentials 00:07:39.970 --> 00:07:43.050 if I move over a couple of centimeters away the 00:07:43.050 --> 00:07:45.709 electrode. So if I want to have a real comparative 00:07:45.709 --> 00:07:48.910 measurement when I use the straps or when I don't 00:07:48.910 --> 00:07:51.370 use the straps, once I apply the electrodes, 00:07:51.589 --> 00:07:53.709 I have to keep the electrodes always in the same 00:07:53.709 --> 00:07:56.250 position when I use the straps or not. So we 00:07:56.250 --> 00:07:58.930 have to require, we couldn't call that subjects 00:07:58.930 --> 00:08:01.449 on another day or one day you do it. straps on 00:08:01.449 --> 00:08:03.449 the other day you do it without straps it had 00:08:03.449 --> 00:08:07.029 to be done all at once so the athletes were supposed 00:08:07.029 --> 00:08:11.310 to go through a run from a 60 percent up to a 00:08:11.310 --> 00:08:15.269 85 percent of lifting sequences of lifting without 00:08:15.269 --> 00:08:18.009 straps and then repeat it again with the straps 00:08:18.009 --> 00:08:20.709 or in a randomized order some of them started 00:08:20.709 --> 00:08:23.009 with straps some of them without straps so in 00:08:23.009 --> 00:08:26.370 reality it's very disruptive of their lifting 00:08:26.370 --> 00:08:29.129 routine so we had problems and finally those 00:08:29.129 --> 00:08:31.860 athletes that were preparing competitions obviously 00:08:31.860 --> 00:08:34.940 had more problems in participating because that 00:08:34.940 --> 00:08:36.740 would have been very disruptive for their training 00:08:36.740 --> 00:08:40.080 routine. Fortunately, we found a very sufficient 00:08:40.080 --> 00:08:44.139 large number of athletes from a local gym, Team 00:08:44.139 --> 00:08:46.539 Soul Miami, amazing people who really wanted 00:08:46.539 --> 00:08:49.639 to go through all this ordeal. And we actually 00:08:49.639 --> 00:08:52.820 were able to complete the study. We used the 00:08:52.820 --> 00:08:55.700 population of sub -elite athletes, athletes that 00:08:55.700 --> 00:08:58.720 had competed in regional and national level. 00:08:59.340 --> 00:09:01.440 The requirement was that they would train at 00:09:01.440 --> 00:09:03.679 least three days per week. Obviously, all of 00:09:03.679 --> 00:09:05.580 them trained five days a week. And obviously, 00:09:05.639 --> 00:09:08.179 they didn't have any muscular injury that prevented 00:09:08.179 --> 00:09:11.019 them from executing the movement in the way it's 00:09:11.019 --> 00:09:12.940 supposed to be executed. All right. How many 00:09:12.940 --> 00:09:14.860 did you have, the participants? How many? We 00:09:14.860 --> 00:09:19.639 had a total of 12 participants, which... gave 00:09:19.639 --> 00:09:22.700 us enough power for our statistical analysis. 00:09:22.860 --> 00:09:25.860 And they were all males, I think, were they? 00:09:25.980 --> 00:09:28.919 Okay, 12 males. All right, now, this is an EMG 00:09:28.919 --> 00:09:32.259 study, so we are measuring muscle activation. 00:09:32.340 --> 00:09:36.039 Do you want to say a little bit more about what 00:09:36.039 --> 00:09:38.620 kind of outputs did you get in your data? You 00:09:38.620 --> 00:09:40.779 know, like when we test, for example, because 00:09:40.779 --> 00:09:42.740 this is something my viewers will be familiar 00:09:42.740 --> 00:09:45.940 with, testing jump, for example. So if you do 00:09:45.940 --> 00:09:48.820 it on force places, you will have forces. You 00:09:48.820 --> 00:09:51.639 can calculate, you can see velocity, you can 00:09:51.639 --> 00:09:55.440 see jump height. So these would be the variables 00:09:55.440 --> 00:09:58.559 people would be more familiar with. With EMG, 00:09:58.659 --> 00:10:01.159 what do you get? What do you work with? Yeah, 00:10:01.200 --> 00:10:04.220 so again, the EMGs are very particular. So like 00:10:04.220 --> 00:10:06.559 I said, because we are looking at the muscular 00:10:06.559 --> 00:10:10.100 contraction that translates into electrical potentials, 00:10:10.100 --> 00:10:12.840 we are looking at the peak of these electrical 00:10:12.840 --> 00:10:16.000 potentials that are elicited when there is a 00:10:16.000 --> 00:10:18.610 muscular contraction. Okay, so... What we are 00:10:18.610 --> 00:10:22.070 actually looking at in a quantity that is a voltage 00:10:22.070 --> 00:10:24.529 that is in millivolts, generally, is the order 00:10:24.529 --> 00:10:27.970 of magnitude. And like I said before, the measure 00:10:27.970 --> 00:10:31.250 itself is not an absolute measure. So if I jump 00:10:31.250 --> 00:10:33.690 from the floor, you can determine how many centimeters 00:10:33.690 --> 00:10:36.549 I elevate from the floor. It's an absolute measure. 00:10:36.669 --> 00:10:38.789 For the EMG, it does not. Why? Because it depends 00:10:38.789 --> 00:10:41.529 on the specific location near the muscle where 00:10:41.529 --> 00:10:44.980 I put EMG. So if I have a... region of my skin 00:10:44.980 --> 00:10:47.360 where there is a little bit more dead skin, the 00:10:47.360 --> 00:10:49.960 resistance of my skin will be higher. This will 00:10:49.960 --> 00:10:51.980 affect the reading of the EMG. So it's a not 00:10:51.980 --> 00:10:54.919 absolute measurement. So we take the maximum 00:10:54.919 --> 00:10:58.340 amplitude of potential that we see elicited within 00:10:58.340 --> 00:11:01.620 the leaf in the condition of using straps, and 00:11:01.620 --> 00:11:04.279 we compare it to the maximum potential that is 00:11:04.279 --> 00:11:06.600 elicited when you don't use it, not using straps. 00:11:06.799 --> 00:11:09.720 We calculate the difference. And you do it per 00:11:09.720 --> 00:11:13.610 muscle? Per all the muscles that we study. So 00:11:13.610 --> 00:11:15.970 obviously, you know, you would like to measure 00:11:15.970 --> 00:11:18.710 everything if possible, right? But again, you 00:11:18.710 --> 00:11:21.070 know, we are in the real world. Like I said, 00:11:21.190 --> 00:11:24.330 it's quite cumbersome and it's also quite uncomfortable 00:11:24.330 --> 00:11:27.509 for the athletes. So what we had to do is to 00:11:27.509 --> 00:11:30.029 measure only those muscles on the dominant side. 00:11:30.190 --> 00:11:32.750 So if the athlete was right -handed, we measure 00:11:32.750 --> 00:11:36.870 only eight muscles on the right side or on the 00:11:36.870 --> 00:11:39.629 left side if the person was left -handed. The 00:11:39.629 --> 00:11:52.450 muscles that we studied were flexors. So we had 00:11:52.450 --> 00:11:55.990 essentially muscles from the upper limbs, shoulder, 00:11:56.230 --> 00:11:58.669 the back, and some of the posterior chain. Those 00:11:58.669 --> 00:12:01.309 that are in the back are obviously even more 00:12:01.309 --> 00:12:04.070 challenging because people tended to sweat on 00:12:04.070 --> 00:12:06.570 the back and it was very difficult to wrap all 00:12:06.570 --> 00:12:09.470 around the chest these gauzes. Like I said, these 00:12:09.470 --> 00:12:11.669 were the challenges that we faced. And yeah. 00:12:11.879 --> 00:12:14.799 So we compared essentially for each muscle, we 00:12:14.799 --> 00:12:17.440 compared these electrical potentials. Obviously, 00:12:17.500 --> 00:12:21.240 as we know, snatch has several phases. They start 00:12:21.240 --> 00:12:23.919 with the first pull and the second pull and then 00:12:23.919 --> 00:12:28.289 the catch. and then the squat, we monitored the 00:12:28.289 --> 00:12:30.769 activation of these muscles throughout all these 00:12:30.769 --> 00:12:33.470 phases. But obviously, we were more interested 00:12:33.470 --> 00:12:36.429 into the first initial phases of pull because 00:12:36.429 --> 00:12:38.710 it's where all the major muscle contractions 00:12:38.710 --> 00:12:41.730 occur and where actually the straps seem to have, 00:12:41.909 --> 00:12:44.870 we hypothesized that the straps can have an effect. 00:12:45.049 --> 00:12:46.870 Obviously, there is not much effect the strap 00:12:46.870 --> 00:12:49.389 can have in the catch position or in the overhead 00:12:49.389 --> 00:12:52.470 squat. It's just that they are not meant to improve 00:12:52.470 --> 00:12:54.549 that part. They are meant to improve the pace. 00:12:54.669 --> 00:12:57.549 So that's why we focus mostly on the phase of 00:12:57.549 --> 00:13:00.309 pulling. Awesome. So what you get at the end 00:13:00.309 --> 00:13:05.230 is the trace of the muscle activation. So the 00:13:05.230 --> 00:13:08.750 potentials. Yes. So what you get is actually 00:13:08.750 --> 00:13:11.450 the trend of activation, spikes of potential 00:13:11.450 --> 00:13:14.789 throughout all the entire movement. And together 00:13:14.789 --> 00:13:18.210 with the DMGs, we had cameras that at the same 00:13:18.210 --> 00:13:20.350 time monitored the movement of the athletes. 00:13:20.389 --> 00:13:23.889 So we could determine when a certain type of... 00:13:23.879 --> 00:13:26.820 spike occurred and that spike was associated 00:13:26.820 --> 00:13:30.460 to the first pool or the second pool or any other 00:13:30.460 --> 00:13:33.440 phase of the leak. So we separated, our analysis 00:13:33.440 --> 00:13:36.519 was comparing with or without the straps, each 00:13:36.519 --> 00:13:38.840 muscle in each phase of the leak with the major 00:13:38.840 --> 00:13:41.559 focus on the first two phases of the leak. That's 00:13:41.559 --> 00:13:44.259 a lot of work. And let's not forget that each 00:13:44.259 --> 00:13:47.299 signal has to be processed and filtered and so 00:13:47.299 --> 00:13:52.159 on. Yeah, I guess that for an engineer. because 00:13:52.159 --> 00:13:56.799 we executed this with my PhD students in engineering. 00:13:57.059 --> 00:13:59.960 This was the signal processing was not probably 00:13:59.960 --> 00:14:02.620 the hardest part of it. Now, I mean, although 00:14:02.620 --> 00:14:06.279 you want to use EMGs, I used to say you want 00:14:06.279 --> 00:14:08.620 to use EMGs. EMGs are nice. They can give you 00:14:08.620 --> 00:14:10.519 a lot of information, but you want to use EMGs 00:14:10.519 --> 00:14:13.419 only when you definitely like to use EMGs because 00:14:13.419 --> 00:14:15.600 there is no other way, right? If you can try 00:14:15.600 --> 00:14:19.600 to bypass, I'm happy to do that. We wrapped up 00:14:19.600 --> 00:14:24.379 twice. from 60 % to 80 % with starting. I mean, 00:14:24.399 --> 00:14:28.460 we had some sort of a mixed progression of stepwise 00:14:28.460 --> 00:14:31.019 and linear progression of the weights. So having 00:14:31.019 --> 00:14:34.500 more repetitions at lower percentages and then 00:14:34.500 --> 00:14:37.679 executing singles, three singles at 80 % without 00:14:37.679 --> 00:14:40.080 straps and three singles at 80 % with straps. 00:14:40.440 --> 00:14:43.179 Are we ready for the results? Sure. So we found 00:14:43.179 --> 00:14:46.759 very interesting results. We found that we had 00:14:46.759 --> 00:14:50.960 made a significant decrease in the mass. activation 00:14:50.960 --> 00:14:55.539 of the forearms up in between 15 to 20 % less 00:14:55.539 --> 00:14:57.820 activation when using the strikes. This also 00:14:57.820 --> 00:15:00.399 reflected a little bit in the lesser activation 00:15:00.399 --> 00:15:05.240 of the bisects, although those were very, very 00:15:05.240 --> 00:15:08.299 small, around 5%. But interestingly enough, we 00:15:08.299 --> 00:15:12.200 saw an increase in the activation of the deltoid 00:15:12.200 --> 00:15:14.360 and the lateral sinus dorsi. They probably had 00:15:14.360 --> 00:15:17.419 the largest increase of activation when using 00:15:17.419 --> 00:15:22.340 the strikes. And in the upper body. And even 00:15:22.340 --> 00:15:26.580 more interestingly, we found an increase in the 00:15:26.580 --> 00:15:29.299 activation of the quad on the vastus lateralis 00:15:29.299 --> 00:15:33.159 that went up to 40 % in some cases. 40 % more 00:15:33.159 --> 00:15:35.379 activating when using lifting straps as compared 00:15:35.379 --> 00:15:38.940 to non -using lifting straps. So in a way, we 00:15:38.940 --> 00:15:42.220 sort of validated our hypothesis that the use 00:15:42.220 --> 00:15:45.379 of lifting straps not only benefits the deload 00:15:45.379 --> 00:15:48.419 of the forearms, but also helps engage more all 00:15:48.419 --> 00:15:51.320 the other muscles that are involved into the 00:15:51.320 --> 00:15:54.309 exercise. And I think that probably, I would 00:15:54.309 --> 00:15:56.350 say that the most important message to me, in 00:15:56.350 --> 00:15:58.990 my opinion, is that the use of lifting or the 00:15:58.990 --> 00:16:02.070 use of straps should be recommended in general 00:16:02.070 --> 00:16:05.350 for general use in strength and condition. So 00:16:05.350 --> 00:16:08.190 we know that Olympic lifts are also used in other 00:16:08.190 --> 00:16:10.529 sports for strength and conditioning. And in 00:16:10.529 --> 00:16:13.409 other sports, athletes may not need to gain the 00:16:13.409 --> 00:16:16.750 level of proficiency in technique like an Olympic 00:16:16.750 --> 00:16:19.629 weightlifter. And they generally focus more on 00:16:19.629 --> 00:16:22.529 pulls rather than execution. in the entire movement. 00:16:22.610 --> 00:16:27.389 Or maybe they power it. They power snatch. So 00:16:27.389 --> 00:16:29.330 at that point, I think that it would be very 00:16:29.330 --> 00:16:31.669 beneficial for them. They could get more out 00:16:31.669 --> 00:16:34.230 of the exercise if they would use straps. Because 00:16:34.230 --> 00:16:36.269 they definitely don't have to train their grip 00:16:36.269 --> 00:16:38.730 strength like a weightlifter would have to. But 00:16:38.730 --> 00:16:41.389 surely they have to train their lower lips and 00:16:41.389 --> 00:16:43.190 their back. And that's just the observation, 00:16:43.190 --> 00:16:46.710 but when you use straps, you may load heavier, 00:16:46.929 --> 00:16:51.139 which means higher weight for the exercise. athlete 00:16:51.139 --> 00:16:53.960 who is doing the exercise. So you can load athletes 00:16:53.960 --> 00:16:56.940 more effectively using straps because the grip 00:16:56.940 --> 00:16:59.860 is not restricting how much they can use. Absolutely. 00:17:00.080 --> 00:17:02.620 There are several studies that have shown this 00:17:02.620 --> 00:17:05.819 is in deadlift that obviously by releasing, by 00:17:05.819 --> 00:17:09.339 not being bound on the way on the amount you 00:17:09.339 --> 00:17:11.220 lift by your grip strength, you can actually 00:17:11.220 --> 00:17:13.579 lift more. And this is also the reason why straps 00:17:13.579 --> 00:17:15.980 are not allowed into competitions of weightlifting, 00:17:16.019 --> 00:17:18.039 right? Because we know that they have actually 00:17:18.039 --> 00:17:19.839 beneficial effect in giving you the opportunity. 00:17:20.140 --> 00:17:22.359 to lift higher weights. But now we measure, right? 00:17:23.039 --> 00:17:25.200 Now we have a quantitative data to associate 00:17:25.200 --> 00:17:28.559 to this probably common sense, obvious or empirical 00:17:28.559 --> 00:17:31.640 observation. You know what goes through my head? 00:17:31.799 --> 00:17:35.519 How much more could I lift in the snatch if I 00:17:35.519 --> 00:17:38.519 would be using straps? That would be a very interesting 00:17:38.519 --> 00:17:42.599 question. I have no idea how much, but it would 00:17:42.599 --> 00:17:44.799 be interesting to test. It would be very interesting. 00:17:45.200 --> 00:17:48.480 Because you say, I may be guessing now, but latissimus 00:17:48.480 --> 00:17:52.559 dorsi, you said around up to 20%. So this is 00:17:52.559 --> 00:17:54.440 for that? It was probably more the latissimus 00:17:54.440 --> 00:17:57.339 dorsi. I think it was probably up to, in some 00:17:57.339 --> 00:18:00.579 cases, up to 30%. If the muscle activation is 00:18:00.579 --> 00:18:03.220 changed so much for some of the muscles, because 00:18:03.220 --> 00:18:06.839 30 % is huge, huge change, how it will influence 00:18:06.839 --> 00:18:09.920 the loading? And because the patterns of activation 00:18:09.920 --> 00:18:12.619 are changed, will the technique have to change? 00:18:12.859 --> 00:18:15.400 Will the very professional... weightlifters, 00:18:15.500 --> 00:18:18.980 so the elite who can do the most without straps, 00:18:19.339 --> 00:18:22.039 will they struggle to do straps or they can do 00:18:22.039 --> 00:18:25.240 more? I don't know. Well, I've seen some YouTube 00:18:25.240 --> 00:18:28.299 videos of elite weightlifters that when they 00:18:28.299 --> 00:18:30.660 use the straps, they do something really impressive. 00:18:30.940 --> 00:18:34.339 They go to weights that are really, really impressive. 00:18:34.559 --> 00:18:39.059 What really struck me is that we had cases in 00:18:39.059 --> 00:18:42.220 which the contraction of the vastus lateralis 00:18:42.220 --> 00:18:45.390 went up to 40%. more. I mean, we're talking about 00:18:45.390 --> 00:18:49.700 a major effect. a major effect. But I mean, this 00:18:49.700 --> 00:18:52.859 did not happen in all the subjects. Oh, interesting. 00:18:53.119 --> 00:18:55.359 I think you need to run another study, Francesco. 00:18:55.539 --> 00:18:57.480 Oh, absolutely. You're giving me a lot of ideas. 00:18:57.759 --> 00:19:00.740 And yes, certainly. We are very interested in 00:19:00.740 --> 00:19:03.460 conducting studies in sports biomechanics. And 00:19:03.460 --> 00:19:06.640 obviously, weightlifting is my passion. And my 00:19:06.640 --> 00:19:09.279 students, I'm trying to involve more and more 00:19:09.279 --> 00:19:11.519 my students also in the practice of the sport. 00:19:11.700 --> 00:19:14.059 I'm bringing them to the dark side, yeah? Yes, 00:19:14.079 --> 00:19:16.299 to the dark side. Excellent. Well, going back 00:19:16.299 --> 00:19:20.180 to the... To my question with how much more the 00:19:20.180 --> 00:19:22.700 lifter is able to lift with the straps. If we 00:19:22.700 --> 00:19:25.240 would know how much, then we can calculate, okay, 00:19:25.299 --> 00:19:28.640 if I want this snatch on the platform, this is 00:19:28.640 --> 00:19:31.900 where I would have to go to with straps or try 00:19:31.900 --> 00:19:34.579 to overload, I don't know, face by face or, you 00:19:34.579 --> 00:19:37.559 know, different methods. Very good question for 00:19:37.559 --> 00:19:41.779 a coach, right? And generally, when I personally, 00:19:41.880 --> 00:19:44.519 when I've trained, I always pull with straps 00:19:44.519 --> 00:19:47.869 all the time. I may use straps during, you know, 00:19:47.869 --> 00:19:51.269 my routine, but only when I am quite far away 00:19:51.269 --> 00:19:53.309 from competition. So when I'm getting closer 00:19:53.309 --> 00:19:56.289 to competitions, I rather not using them because 00:19:56.289 --> 00:19:58.269 I understand that there is, there might be a 00:19:58.269 --> 00:20:00.170 change in the technique or the way you approach 00:20:00.170 --> 00:20:02.970 the lift. And also you want to still keep your, 00:20:03.009 --> 00:20:05.950 in a way, your grip straight, in a way. So it's 00:20:05.950 --> 00:20:07.849 definitely an excellent question for a coach. 00:20:08.029 --> 00:20:10.589 I have one more question about EMG and weight 00:20:10.589 --> 00:20:14.250 classes. So will the EMG signal or the reading 00:20:14.250 --> 00:20:17.490 differ? depending on how much fat tissue the 00:20:17.490 --> 00:20:19.750 athlete will have. Because lower weight class 00:20:19.750 --> 00:20:22.309 athletes tend to be a little bit leaner than 00:20:22.309 --> 00:20:24.609 super heavy athletes, for example, where there's 00:20:24.609 --> 00:20:27.509 no limit on the weight, body weight. So they 00:20:27.509 --> 00:20:30.769 usually will hold a little bit more fat tissue 00:20:30.769 --> 00:20:35.150 because they can. Again, I mean, the fat tissue 00:20:35.150 --> 00:20:39.690 has an effect on the overall impedance, the electrical 00:20:39.690 --> 00:20:42.309 resistance, if you want, in many elements of 00:20:42.309 --> 00:20:45.170 your body. So obviously include... in a fat layer 00:20:45.170 --> 00:20:48.650 may change in comparison the amplitude of the 00:20:48.650 --> 00:20:51.269 potential but again we have to remember that 00:20:51.269 --> 00:20:54.650 the measurement of an EMG is not an absolute 00:20:54.650 --> 00:20:57.369 measure okay so we have always to compare to 00:20:57.369 --> 00:21:00.089 something so in this particular case of this 00:21:00.089 --> 00:21:03.109 study we compared the same exercise executed 00:21:03.109 --> 00:21:05.849 with a garment and not a garment okay if I want 00:21:05.849 --> 00:21:09.670 to just study what is the activation of a muscle 00:21:09.670 --> 00:21:11.730 for doing snatch in general without comparing 00:21:11.730 --> 00:21:14.559 with anything obviously my reading of the electrical 00:21:14.559 --> 00:21:17.259 potential this by itself doesn't mean anything 00:21:17.259 --> 00:21:20.099 again because it's the part issue the way you 00:21:20.099 --> 00:21:22.579 apply so what we generally do as a comparison 00:21:22.579 --> 00:21:25.420 we calculate the maximum voluntary contraction 00:21:25.420 --> 00:21:28.119 of the muscle which is a baseline measurement 00:21:28.119 --> 00:21:31.059 essentially we have techniques to stimulate the 00:21:31.059 --> 00:21:33.380 muscle the specific muscle that we want to target 00:21:33.380 --> 00:21:35.880 we want to monitor to its maximum maximum contraction 00:21:35.880 --> 00:21:38.440 at this maximum contraction we read the potential 00:21:38.440 --> 00:21:40.619 and this electrical potential would be the baseline 00:21:40.619 --> 00:21:43.180 would be the maximum effort that you can possibly 00:21:43.180 --> 00:21:45.380 put into the contraction of the muscle. Then 00:21:45.380 --> 00:21:47.900 we execute the exercise and we read another electrical 00:21:47.900 --> 00:21:50.119 potential. And then we refer this electrical 00:21:50.119 --> 00:21:52.900 potential to its mass. So we know that during 00:21:52.900 --> 00:21:58.839 that exercise, I used 60%, 70%, 90 % of my maximum 00:21:58.839 --> 00:22:01.559 capability of contracting that muscle. So if 00:22:01.559 --> 00:22:03.400 we are looking at weight classes, yes, there 00:22:03.400 --> 00:22:05.200 is a difference in body composition. That's for 00:22:05.200 --> 00:22:06.880 sure. That's for sure. It's undeniable. Does 00:22:06.880 --> 00:22:09.599 this affect the reading of the EMG? Not really, 00:22:09.619 --> 00:22:11.880 because it's a relative measurement. We always... 00:22:11.920 --> 00:22:13.880 have an internal comparison. Then it depends, 00:22:14.099 --> 00:22:17.180 it boils down to the sensitivity of your EMG, 00:22:17.319 --> 00:22:19.599 if it's capable of capturing that potential. 00:22:19.700 --> 00:22:22.740 And generally they are used even with large body 00:22:22.740 --> 00:22:26.339 mass index people. Pretty sensitive. Yes. Let's 00:22:26.339 --> 00:22:29.259 maybe try to bring it all together. So two, three 00:22:29.259 --> 00:22:32.279 points, maybe what you want coaches to get out 00:22:32.279 --> 00:22:34.759 of this study. Main points. Well, I would say 00:22:34.759 --> 00:22:38.039 that in the first place, we showed with quantitative 00:22:38.039 --> 00:22:41.019 data that using liquid straps is a beneficial. 00:22:41.130 --> 00:22:43.910 effect on deloading the forearms. So it can be 00:22:43.910 --> 00:22:46.990 indicated, specifically indicated, when we have 00:22:46.990 --> 00:22:49.529 problems of fatigue, for instance, for the forearms. 00:22:49.690 --> 00:22:52.210 The second point that we found was that, obviously, 00:22:52.450 --> 00:22:56.269 together with the deloading of the forearms, 00:22:56.450 --> 00:22:58.730 the use of straps also have a beneficial effect 00:22:58.730 --> 00:23:01.970 in increasing the activation of the muscles of 00:23:01.970 --> 00:23:04.990 the back and the lower ribs. So in view of building 00:23:04.990 --> 00:23:07.130 a program of strength and conditioning for the 00:23:07.130 --> 00:23:09.250 athlete, whether the athlete is a weightlifter 00:23:09.250 --> 00:23:11.769 or an athlete... of a different specialty it 00:23:11.769 --> 00:23:14.450 may be could be an option the use of the straps 00:23:14.450 --> 00:23:16.390 in order to enhance the muscle attraction but 00:23:16.390 --> 00:23:18.930 obviously we always the other point is last point 00:23:18.930 --> 00:23:21.049 probably is we always have to keep in mind that 00:23:21.049 --> 00:23:24.609 weightlifting as a sport is done at a competitive 00:23:24.609 --> 00:23:27.509 level is done without straps so we cannot abuse 00:23:27.509 --> 00:23:29.730 all right at some point we have to go back to 00:23:29.730 --> 00:23:32.029 you know the regular weight excellent okay two 00:23:32.029 --> 00:23:34.730 more questions to finish the first one is which 00:23:34.730 --> 00:23:37.190 is your favorite lift that's a tough question 00:23:37.190 --> 00:23:38.930 because it's always love and date you know it 00:23:38.930 --> 00:23:41.940 depends on my performances are very alternating. 00:23:42.220 --> 00:23:46.240 So I would say that now I would say that definitely 00:23:46.240 --> 00:23:49.039 snatch is my favorite lift. I think in general 00:23:49.039 --> 00:23:51.000 it's my favorite. Are you asking for the lift 00:23:51.000 --> 00:23:53.099 or the lifter? The lift, yeah, yeah. Which one 00:23:53.099 --> 00:23:55.000 is it? Yes, I think that the snatch is probably 00:23:55.000 --> 00:23:58.279 the most representative type of lift of weightlifting. 00:23:58.599 --> 00:24:01.900 It really encompasses the explosiveness, but 00:24:01.900 --> 00:24:03.960 also the mobility, the capability of a person 00:24:03.960 --> 00:24:06.319 to the agility and the mobility of a person. 00:24:06.359 --> 00:24:09.000 And also if you want the grace of a person. in 00:24:09.000 --> 00:24:11.720 the movements. It's fascinating. It is. It's 00:24:11.720 --> 00:24:14.339 very well executed. It's really fascinating. 00:24:14.460 --> 00:24:16.759 Do you have your favorite list there? Oh, many. 00:24:16.980 --> 00:24:19.059 But since probably we are talking about snatch, 00:24:19.539 --> 00:24:22.660 I have to say that I am very, I always fall in 00:24:22.660 --> 00:24:26.200 love with the way Alexey Toropty snatches. He 00:24:26.200 --> 00:24:29.000 is extremely graceful and powerful at the same 00:24:29.000 --> 00:24:33.359 time. And his technique is just, I really hypnotize 00:24:33.359 --> 00:24:36.019 me when I see him. Okay, last question is if 00:24:36.019 --> 00:24:38.960 people want to see what you are. Up to what your 00:24:38.960 --> 00:24:41.640 research is at the moment, where should they 00:24:41.640 --> 00:24:46.519 go online? Okay. So we have our X account with 00:24:46.519 --> 00:24:52.460 all our updates and the handler, the analyst, 00:24:52.720 --> 00:24:56.539 Biomag with capital B and with an H again, underscore 00:24:56.539 --> 00:24:59.299 capital U, capital M as University of Miami. 00:24:59.519 --> 00:25:01.380 Awesome. And then you can see all our updates 00:25:01.380 --> 00:25:03.819 and you also have the links to our, to the website 00:25:03.819 --> 00:25:05.940 of our lab. That's amazing. Thank you so much, 00:25:05.980 --> 00:25:08.710 Francesco. was a pleasure my pleasure bye