Thread by @Scienceofsport

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions Hi Lee. Heard your discussion on the latest pod, and appreciate the views raised (though I don’t agree with some of the criticisms of the process). regarding the science, the principle or conceptual approach to the issue is very much the same as it was for head injuries. (1/)

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions That approach is a classic “public health model” where the risk is first identified, then risk factors are assessed, and then attempts are made to mitigate, reduce or avoid those risk factors altogether. I’m know you’re familiar with how this played out in the concussion space

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions In this area, the same recognition of risk was raised. What you guys discussed on the pod, which wasn’t entirely true, is that there is ONE anecdote (the deckchairs) that raised this concern. There were actually multiple concerns raised. So that was part of it - the sport was

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …being asked by its members to look at the risk. Then in addition, the IOC was mandating federations to develop their own policies. Then the research was coming out on the effect of lowering T on various physiological attributes (another paper is due out any day now, from the US

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …military). Plus, I don’t think it’s wrong to say that the debate was growing in a ‘societal sense’ as the prevalence increased (right or wrong, this is the ‘milieu’ in which the questions were asked. So, with all that going on, World Rugby basically said the following: “What is

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …the best quality approach we can take to the complex issue? How can we devise a robust process that recognises all the relevant issues?”. We then identified four domains that we needed to hear from:
1. Legal
2. Biological/scientific/performance
3. Medical
4. Socio-ethical (for

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …lack of a better term). The next thing we said was that we don’t believe a single committee can be comprised of stakeholders from all those, because a) you can never have enough of those viewpoints because if you have a person representing X, you need someone for Y. A needs B

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions And so forming a committee that would “internally” or itself evaluate the evidence and develop a policy would expose us to massive risk of bias & accusation of agendas etc. So what we said was that we’d run it as a very transparent process in which we’d invite, quite deliberately

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …the protagonists from each of those four domains, we’d put them in a room together, and then we’d put every single perception and issue and risk and piece of evidence into the light. So we had two lawyers, one pro, one con. Two scientists, two medical teams, always with one who

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …would present evidence for inclusion, and the other who would argue against. We wanted debate. We were looking for disagreement. It was basically saying “you offer us your scientific evidence, and let’s hear the other side critique it. X presents their legal liability position

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …and Y can explain what’s wrong with it. This was done in front of a working group that did comprise legal, medical, scientific and administrative expertise. We looked at the IOC, where a group of men devised the trans policy, and said that we didn’t want that either, so the

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …group was put together with people with playing, management and legal experience in the women’s game (some will criticise this, I’m glad we did it). In any event, the two day meeting was then intended to get EVERYTHING out. No group was censored, no limits imposed. The idea

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …was that all four domains would be raised. So we invited advocacy groups on both sides - for trans inclusion, there were 2 groups, against trans inclusion, one group. Every issue had a “for” and “against”. And I can honestly say, hand on heart, that we went into that meeting

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …with the intention of balancing all these colliding rights - what you eloquently referred to as “fear and vulnerability” in the podcast, is actually an issue that manifests as colliding rights. Our sincere intention or “mission statement” was this: Can we balance this and find

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …a compromise that satisfies what IS a complex issue. However, from the two days, the thing that struck me most is that the scientific evidence for retained physiological advantages (with risk and fairness implications) is so strong, and the evidence that this risk is NOT there

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …is so weak, that the intention of balancing the rights is simply untenable. Therefore, the conversations shifts, and it becomes about tradeoffs and priorities. Now, I heard Lee and Robbie discuss this, and I don’t agree that “all there is is anecdote” - I think maybe I have a

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …different definition for what anecdote means! But there is only anecdote on one side. On the other, there is a mountain of evidence for very large maintenance of speed, power, strength, mass and in particular lean mass, even after T levels are reduced. This evidence is strong.

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions Where there remains a gap in the evidence, and Josh (I said Lee earlier, my apologies, I meant Josh and now I can’t edit it!) and Robbie are correct is that there is no rugby specific study that actually quantifies injuries. But that’s not surprising & nor is it all that crucial

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …to the assessment of risk. “Risk” is by nature probability. In the HIA study we did, we quantified HIA risk per 1000 tackles of each type. You know that in that cohort, we didn’t find a single instance where a head high tackle worthy of a red card caused a head injury? That’s

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …because the number of such events is so low that you would need an enormous study to find it. A similar concept is true here. However, we can assess risk given that the mechanism of injury is known - transfer of kinetic energy and impulse that exceeds a body’s capacity to

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …withstand it. So things like the inertia of the head during a tackle, the acceleration of the head, the load on the spine, the mass times velocity, and force applied, all create risk. An analogy here is that we know that if heavyweights fought lightweights, the risk to the

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …smaller guy is greater. that’s never been “shown” in the epidemiological sense, but it’s “known”. Now, when we consider rugby, you guys discussed this notion of all shapes and sizes. Ironically, I think it was you who joked that if you spent your rugby career getting smashed by

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …bigger people, you might stop playing. In women’s rugby, there is obviously a range of mass between the light player and the heavy one. Same for men. The problem is that if you allow mass from men to cross over into women, then that range becomes enormous. So spread goes from

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions 50% difference (lightest to heaviest) to about 110% difference. At typical male player is heavier than the heaviest 1% of women, so any player heavier than a typical male who enters that group will increase the range. Now, we know that mass, all by itself, creates a risk and a

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …performance implication. This can be modeled, to show how head inertia and acceleration increase well beyond what is normal even when heavy tackles light within women’s rugby. So that sets the lowest possible increase in RISK FACTOR for injury as a result of MASS ALONE

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions Now, we have to consider what effect speed creates - if males are 15% faster, then a 110kg male will carry much higher kinetic energy and momentum into contact than a 110kg female (the top 0.1% of women). So whatever effect exists to create risk goes up even more. Next, we have

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …to also consider that there is active force production during contact. Punch power has been shown to be 160% higher in men. Static strength is 50 to 70% higher in males. The protocols to reduce T levels only reduces this by 5 to 10%. That leaves behind very large differences

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions So we basically now have a picture where mass, speed, strength, power and the ability to “receive” contact are skewed in a way that simply doesn’t exist. If, and this is possible, the person making the transition is a lighter male (around 25th percentile), with lower than average

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …strength and power, then they would slot in somewhere in a typical female range for all three those factors. But risk management, at least in a legal sense, has to apply a precautionary principle in which you consider either the typical or the extreme high risk scenario. For

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …example, you don’t look at a bunch of guys playing Russian Roulette and say 83% of them were fine, thus it is declared safe. Its risk exists because of the worst scenario. So our assessment of the evidence is that it is compelling and strong to suggest that not a single

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …element that creates risk is reduced to any meaningful degree by the current protocols, that the size of what remains as a risk factor is large, and thus can reasonably be foreseen to pose a risk that a player cannot reasonably accept. There is also a performance implication

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions What I’d love to do is the same thing you want - measure the power output and actual energy transfer in real tackles where a typical male tackles a typical male, and compare to typical female vs typical female, and large male vs small male etc. I hope we can do that, and we have

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …been very clear that we wish to explore research on this. But the current research picture is very clear the other way - the risk factors do not go down, and when applied to the rugby contact situation, this exposes smaller, slower, weaker players to very large increases in

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …risk. Yes, it’s modeled, not direct and people will criticise that, but it makes for a really difficult argument to avoid in terms of what is ‘prudent’. In this respect, the action taken is identical to that taken for HIAs and concussion with law change. If there is a risk that

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …is known to exist, then even if it is rare, it must be mitigated unless that risk is part of the sport (eg: executing a legal tackle). So what I didn’t agree with from Josh and Robbie is that all they saw was anecdote. There is good evidence on the biology and if applied to

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions …rugby, it makes for a very difficult decision, because you realise it’s probably not viable to ‘balance’ the three factors. We really sought to do this in a way that gave everyone a voice, I know we’re being criticised for it now, but nobody was excluded from the process.

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions Anyway, wow, that’s a mouthful. The short answer (TL;DR) is that the principle is the same - identify the risk factor and then create an intervention that avoids it, or minimise it. In time, I hope the evidence grows and maybe even exists as direct evidence.

@bloodandmud @smash_rugby @CarolineLayt @SquidgeRugby @KirstiMiller30 @VeritySmith19 @CardiffLions A final point - World Rugby didn’t take it to the Guardian. We sent it out to every single Union for consultation and feedback. The ‘silence’ that was criticised is because we’re actually still trying to gather feedback through official channels.