Good afternoon everyone. Thanks for being here. I hope everyone's commute was uneventful I want to first thank our teams at VTrans and municipal employees for the long hours working overnight and today Applying the roads be very much appreciate all the good work Speaking of roads today. We want to focus on the importance of planning ahead and investing in our critical infrastructure needs In my budget address as you might recall. I talked about the more than $150 million and surplus dollars we propose in the budget to make sure we can leverage even more federal dollars over the next few years Between all the federal programs passed recently like the bipartisan infrastructure law and the inflation and reduction act Billions more will be available to the states in addition to all the ARPA money currently spending But unlike ARPA these programs are more traditional and Requires states to match a percentage of the money themselves in order to receive the federal money In the return on investment is incredible We will receive a minimum of four federal dollars for every dollar we invest And in some cases it's ten times that amount And here's the good news We don't have to worry about where that match will come from because we have the money right now This year we have a record amount of state surplus Which is why I believe it would be wise to do Dedicate a hundred and fifty million of it to guarantee these funds are available when we need it The reason I'm advocating for this set aside is that we really don't know how the economy is going to do over the next few years At our e-board meeting in January The legislatures own economists told us we are likely to see revenue growth drop significantly in the coming years That means we might not have the match money we need Putting important projects at risk Also putting us in a tough position of either cutting programs Or raising taxes And neither are good options This is really about fiscal responsibility and good government thinking ahead and being prepared Dedicating the funding now would also provide certainty to our communities And the partners who do the work so they can plan ahead And if there is an economic downturn as many predict The economic activity these projects provide will help people stay employed In our economy moving Secretary Moore and Flynn will go into more detail about the much needed infrastructure We're talking about and they are a layer from ruttland and katie buckley from vlct We'll talk about how communities benefit from these investments Because as I said in my budget address This investment is all about communities Like work on route 78 in swanton Route two between cabot and danville route five in rattleboro And connecting their regions with safe roads and clean water with projects in bethel northfield and ruttland Not to mention the significant amount of broadband funding as well We have a golden opportunity to be pragmatic And help assure that our infrastructure and economic needs are met in the future And i'm hopeful the legislature sees the merits of the strategy as well i'll turn it over to secretary clinton for more Thank you governor and good afternoon The infrastructure investment in jobs act Has positioned vermont to realize the largest dedicated transportation infrastructure investment Likely since the onset of the eisenhower interstate highway system Vermont's transportation program is funded from the federal highway administration in five year cycles referred to as fast-stack transportation This most recent five-year cycle is delivering 1.7 billion dollars to the agency of transportation Which is an increase of 572 million dollars from the prior five-year cycle With that comes additional pressures as you've heard the governor say To have the required state match, which in our case is typically 20 to draw down those federal dollars As the governor has said Ensuring right now that vermont has secure and dedicated match money To utilize these federal funds to deliver increased transportation projects across our state Just makes sense And it will guarantee our ability to leverage this historic opportunity At that return on investment of four to one The governor's as recommended budget for 24 Identifies 79 million dollars from the current general fund surplus for fiscal 24 25 and 26 This will put 342 million dollars in transportation projects to work across vermont As a general practice, there is never a more cost-effective time to plan and to begin large construction projects than the present Failure to secure this funding now can have ripple effects across the entire project delivery pipeline Delaying our ability to advertise to go to bid into award contracts Of 754 projects as of today 223 transportation projects across vermont will have their delivery schedules impacted over time A few examples of actual projects in real impacts are In orwell reconstruction of shoulders in widening route 22a Construction is currently planned for 2027 and it would be delayed until 2030 In cabot to danville Reconstructing u.s. Route 2 Construction is planned to begin in 2026 and would be delayed until 2029 In norton up in esssex county replacing bridge number 41 on route 114 Construction is planned for 2028 and it would be delayed until 2032 In franklin replacing sidewalks on main street Construction is planned to begin in 2023 and it would be delayed until 2025 Wolkett replacing bridge 6 Construction is planned to begin in 2025 and would be delayed until 2027 In west rottlen us route 4 Replacing bridge decks on bridge 13 and 14 both east and westbound Construction is planned to begin in 2029 It would be delayed until 2035 And brattleboro reconstruction of us route 5 putney road Construction is planned to begin in 2028 and it would be delayed until 2033 But locking in these funds now will yield faster More predictable projects as the governor said with substantial long-term savings Guaranteeing that federal investment of at least four to one And it does also ensure that we aren't put in a position in leaner economic times to make difficult decisions Over what to cut or what taxes and fees to raise to cover the increased state match realities Doing this now will allow vermont communities and our industry partners the predictability to plan and to get things moving on these projects sooner And you can see from the map the projects at risk cover counties and towns across the state of vermont Vermonters need to be aware of these projects And they need to be aware of the delays to these projects if match is not secured with certainty And now I would introduce secretary julie more Good afternoon I think it probably can go without saying but vermont has some of the oldest infrastructure in the country And with age comes a whole lot of need Part of the challenge with water infrastructure, which is the centerpiece of the agency of natural resources Is that it's often out of sight and therefore out of mind But just because it doesn't have our full attention. It can't be assumed to be working well Water infrastructure is often the most valuable asset a community owns with the total value of pumps pipes and treatment plants Exceeding $50,000 for each household that's connected to the system This valuable infrastructure requires significant ongoing investments to properly maintain it and prevent challenges to public health The environment economic growth and climate resilience Based on agency projections, there will be roughly two billion dollars of investment needed in water infrastructure This means drinking water wastewater and storm water over the next 10 years alone in vermont This is to both refurbish existing systems and to prepare this essential infrastructure for the increasingly disruptive and potentially devastating effects of climate change Fortunately, we are at a unique point where there is unprecedented federal resources available to invest in water infrastructure vermont is eligible to receive an infusion of nearly 320 million dollars into our state revolving loan funds as part of the infrastructure investment and jobs act The revolving loan fund program is an epa partnership that provides communities with grants and low-cost financing For a wide range of water infrastructure projects In order to access these federal funds, however, vermont needs to provide $27 million in state match and the governor's fy 24 recommended budget Creates a reserve that ensures vermont will have that required match These resources will be used to support dozens of projects as shown on the map to my right And rolls up to things like $155 million to refurbish existing drinking water and wastewater systems To ensure that this core infrastructure continues to support vibrant communities Nearly $150 million to support lead service line replacement projects across vermont, which will improve drinking water quality And more than 40 million dollars during the same time period to address emerging contaminants like PFAS by improving drinking water and wastewater treatment These projects are significant undertakings that secretary flin spoke to that require robust planning and engineering design This means that there's often a long lead time needed for a community to ready a water infrastructure project for implementation And given the level of effort needed lead time and competing demands on community priorities Confidence that this funding will be available to support implementation when the time comes is critical If vermont were to forego making the commitment this fiscal year It will add uncertainty for communities making it harder and potentially more expensive to plan for and execute on these critical projects In fully committing the state funds to access literally hundreds of thousands of millions of dollars in federal resources It makes clear vermont's commitment to supporting our communities and investing in critical water infrastructure projects And with that I will turn it over to katie buckley from the league of cities and towns Hi there during the summer of 2021 Towns cities and villages across vermont took a big leap in accepting over 200 million dollars in local american rescue plan act funds Many who have never worked with federal money before accepted it With fear anxiety and uncertainty of what it really meant to manage and spend these dollars without final rules for them even being established yet They accepted this money with the hope and promise that their local ARPA money Can unlock and leverage additional grants that would soon follow through the infrastructure investments in jobs act the bipartisan infrastructure law And the inflation reduction act over the last 18 months Communities of all sizes and capacity levels across the state have taken their time been patient and are thinking bigger They understand that if there was ever a moment to be strategic and take advantage of one time money to help make big investments To repair and replace crumbling infrastructure or develop new infrastructure Now is that moment. It's a rare opportunity one that most of us in this room will never see again Towns cities and villages can use their local ARPA money as much needed grant match to leverage other federal dollars Often towns big and small struggle to come up with that grant match But now with ARPA they have it in hand rare They're relying on the state of vermont to pull down its share of federal money That's available now so that we all of us can emerge from this moment stronger and more resilient With so many competing priorities. It's hard to set aside the state's share of grant match But it is critical to do so in this moment if we do not we lose this rare opportunity Crumbling infrastructure itself will not heal New infrastructure to meet our housing crisis climate initiatives and make us safer and more resilient will not just magically appear All of it is necessary if we do it now vermont's win if we do it later vermont's lose We'll put this work off and onto the backs of taxpayers with a growing price tag And we push vermont deeper into a crisis of affordability Our towns cities and villages are waiting for the state to deliver these federal dollars so that they can do their part To make transfer transformational changes in their communities We're grateful to the governor and his administration for the working so hard to bring these dollars to vermont To ensure this happens And at this point i'll pass it to mayor david aller Okay purpose because this is exactly what we did Was setting aside 400 000 dollars from our our allocation of 400 4.5 million dollars For the same reason to have readily available matching funds for state and federal grant opportunities It's a good strategy Whether it's water sewer or stormwater infrastructure Or traditional roads and bridges Good infrastructure can open up so many opportunities for our cities and towns for example Roland has 7.85 million dollars in fine requests on the ballot on town mean To continue our aggressive schedule of infrastructure improvements Which are so vital to our economic development efforts You know as mayor I also know it's important to plan ahead Sometimes you don't see the fruits of your investments you make run away But that doesn't mean they're not worthwhile Since first being elected our dpw commissioners first jeff whiteburn and now jim rotondo Have worked closely with state government to identify projects and available funding from the various sources For our infrastructure needs You know a new government Anticipating needs and being proactive in having a degree a degree of certainty helps people plan That's why it makes all kinds of sense for the state to set aside this money now While we have it in surpluses To ensure we can take full advantage of federal funds in the years to come Where we don't know if state coppers will be as full As the governor mentioned knowing we had projects on the horizon And the funding to achieve them can also help keep people employed, which is so important In the economy moving Moving if we see tougher economic times ahead as many people predict So in close, I believe the state of ramon as well as the citizens of roland will benefit from this strategy As we stretch federal balance as much as we can and plan for the future for our children and grandchildren So thank you again for this opportunity. I appreciate it very much. It's good to see everyone and I will now hand it back to the governor thank you very much mayor and At this point in time, we'll open up to questions You hearing from your colleagues in the legislature a a willingness or a desire not to set aside Match money. I mean, I know the legislature is still building their budget But have you heard of any of them not doing this? I'm hearing a little bit about There are some legislators that are fully supportive of making sure that we have the money We need for a match and then I'm hearing from others Maybe they had other priorities for surplus dollars. So I'm hearing a mix mix response We want to make sure the message is loud and clear. This is very important to me And and I think that it's important to the state of Vermont It's important to our economy to make sure that we have these dollars That we have right now that we can invest in these projects for the future And there's no better time than now to set that aside raises The with all of these infrastructure projects the question about workforce as well. I know that's been Especially for the water sewer and road projects How are we faring and how are we looking as these Money's are coming down the pike in terms of our workforce to build these out Yeah, there's no doubt. We have a workforce shortage in the state. We talk about that a lot But but I will say The industry seems to have been able to keep up In fact, I've heard from some who are looking for work at this point in time So again with a possible downturn in the economy Having this money and making sure there's some predictability in the future some certainty Will keep the economy rolling and I think everyone is wondering How will how will this land? How will the economy land? And when will the inflation stop and when when will we need this and I think I think it's uh has a lot of merit to put it aside and make sure that we're prepared right now um secretary Flynn listed off a number of projects that could face multi-year delays If Vermont is not able to come up with the matches Are you saying that those delays would come to pass if lawmakers don't allocate the match money in fy 24 If we don't have the match money in general Because i'm not sure that we'll have it in the future Because we don't know if we're going to have surpluses We've been very fortunate in the six years. I've been Governor about at least half of them We've had surpluses But previous to that There was a long stretch Where we had no surplus in fact we had deficits And I've been in business. I've been in the state. I've been in this legislature I'm part of this institution for a number of years and business Over three decades in this in in this environment Over two decades. I've seen the ups and downs in our economy and a lot of folks here have not And I know I remember scraping together trying to find match money so that we can move These projects forward and not being able to do it delaying projects as a result again These dollars require a match from the state And if we don't have the match then we don't get to do the projects So I'm very concerned about that. I just want to make sure that we Focus on this because this will give give us and the state certainty that these projects will come to bear I mean we saw the state's infrastructure grades come out last week Kind of emphasizing the need to improve roads bridges Everything that you guys are saying But what does that C grade mean to you specifically? Does it just really enforce what you guys are saying to that? Well, we have done better in a couple of areas. I think our bridges We we increased our rating, which is good news I believe a lot of that and this is maybe the Secretary can weigh in on this as well, but I think that was a result of Irene We received a lot of federal dollars to replace a number of bridges that helped us catch up a bit Again, if not for that federal money, I'm not sure that we'd be in that position today so We rely on a federal funding in the state In almost every way and I think we have to We have to weigh what's happening in Washington at this point We've We've already they've extended themselves quite a bit. I think they're going to be pulling back I think without senator Leahy there as well We won't be receiving a lot of the federal money. We've been we've been counting on over the last few years So all of that together brings me to the point where If we have the money now Let's make sure that we invest it in the right way So there's some certainty for the state of Vermont and And I'll say again areas In cities like Rutland for instance with some of the oldest water infrastructure in the state Some of that mayor. I think it's over 100 years old if I remember right Are you 25 actually? Yeah So so again, it's exceeded its useful life And this will give us what we need it won't catch us up We'll still need to continue Making these investments with our own state money and with regular Federal money that comes our way But this will help us advance and and maybe next time with the The engineers coming out with their their grading that maybe we'll move up the ladder again Do you want to talk about that at all anything? Thanks governor specific to the Pavement condition road condition and bridge report in the engineering study released last week The agency of transportation has a very Thorough and robust asset management program And it it is driven to help us choose the right projects at the right time In the right place if you will to Repave or to redec bridges and things like that So we are fortunate to be far ahead of the national average on bridge deficiency rating And we I think have 28 percent of our pavement in Vermont is poor or or very poor Which is an improvement, but it's not good enough because if that's where you live It's a hundred percent of your experience and we recognize that But the other thing I would say is Infrastructure you never reach a static completion It everything is deteriorating right now as we talk Every road we repaved five years ago is deteriorating So I think one of the things that the governor is trying to point out is this opportunity for this historic uptick in funding To to make us able To get so much more done than we would otherwise Is really just something that We should capitalize on unrelated, but uh town meeting date rate is coming up Week to week sessions swine by how how what's your assessment of As you mentioned lots of new lawmakers new energy in the building. How how is this session Going for you and some of your priorities? Well again, um, a lot of the budget adjustment The the dollars that we put forth in that Were included. That's the good news. There were some areas that we have We saw as problematic and they're working their way through that right now. I'm hopeful That we'll be able to come to agreement in the end on that so Getting the budget adjustment pass is important before town meeting break And then we'll see. I mean, there's some other good news. I mean, let's talk about good news for a bit The housing bill that the senate passed out of committee That's a great bill. It has a lot of attributes We'll see what happens to it when it goes through natural resources And gets through appropriations and then goes over to the house But at this point in time, it's a strong bill moving in the right direction So there are a number of initiatives that that have been I see as positive But we have a long ways to go and I there's some you know, there's some storm clouds on the horizon What have you made about the affordable heat act? There's a storm cloud that I'm seeing Again, I as you know, I vetoed the Clean heat standard last year for a variety of reasons one of them being that it went to the public utility commission Without coming back to the legislature for full review and passage as a as a bill And it appears that's moving as it came out of the senate natural resources Moving that same direction. So I'm I'm very concerned about that I think in these times, I think again for monitors are looking for more certainty And this gives them anything but certainty in the future and I'm just Not convinced that we're prepared We have the same goals But but I think their timeline Is very aggressive and and I'm not sure it's attainable, especially after Coming back. I think we talked about this last week In the press conference about my experience at the national governance association Being part of of one task force Looking at the grid in particular And I'm not sure we have the capacity at this point in time to do that and I again I think about they're all worthy goals But when you become More pragmatic and and look at the practical aspect of this take for instance If you have a Someone living in a mobile home, for instance Paying six bucks a gallon right now for kerosene Because they have above ground fuel tanks And it has to be a lighter grade so it doesn't freeze So they're already paying a buck more than number two fuel at least So they're going to continue to pay that money unless And it could be more because their fuel supplier Now has to buy appears would have to buy some credits Which will cost money They'll have to pass that on to customers. So this person in the mobile home Will have to pay more money for fuel unless of course They decide to put in a heat pump or they get a A vehicle that It's electric and but when you think about like a Typical mobile home or a house that's been built pre 1972 which there are a lot of them in vermont They all have 60 amp services to have a heat pump and To to charge up your vehicle You're going to need a minimum of a hundred amp service In that in that in your home So you take a mobile home. For instance, this may be valued at $8,000 and you ask an electrician to put in retrofit a new Box a hundred amp box or or bigger It's going to cost thousands of dollars Thousands of dollars that person doesn't have And so when you start working your way through How we get there? I don't know if they've done the math And I'm just not sure That this isn't putting pressure on the very very people you're trying to help


Okay guys, this is the brand new Belkin iPhone mount with MagSafe. I've been waiting for this so I can use my iPhone 14 Pro Max as a webcam. This is also known as continuity camera. Let's go ahead and open this. I purchased this from the Apple website. It comes in just under 30 pounds. Not only does it just mount your phone onto your MacBook Pro, but you can just use it as a handle for your phone if you just wanna place it down on the desk and use that to watch movies, for example. But let's take a look at the Belkin mount. And already I can feel it's not too lightweight. It might be heavy duty. It comes in two colors, but I got the one in black. I just think it looks a little bit nicer. So you have the silver clip there. This one is basically just to use your phone as a mount on the desk or if you just wanna hold your phone by putting your finger through it like that. The main thing for the webcam is this tiny little slot here that pops out with the Belkin logo on it.  So let's try it with my iPhone 14 Pro Max. So I'm just gonna place this on that. And it's actually a very, very strong magnet, much more stronger than a lot of the MagSafe accessories like my car mount and any other mounts that I use. This one actually really holds it quite well. Even if I do a lot of shaking, it will not fall off. Of course, I don't have a case on this and most likely all of you guys watching will have a MagSafe compatible case on your iPhone. So I will showcase this with the case and without the case just to show you the strength as well. If I just wanted to use this just to prop my phone like this, watch something on there, maybe I'm on the train to work, then that's absolutely great to do. And it doesn't take up too much space. So I feel like this is a very nice compact way to maybe just use your phone and you can actually just twist it however you like to get it comfortable. But if you wanna use it for a webcam, which you might be purchasing it specifically for, then this has to be set in a specific way so that the camera and the lenses face you when you're using your laptop. So let's go ahead, put this onto my MacBook and see how this performs as a webcam. Okay, as I mentioned, make sure this is mounted the right way around so that the lenses are facing you. Just going to pop this out. It's a very tiny little rubberized grip on that and it places very well and very quickly and easily onto your MacBook Pro. Of course, you need to make sure your screen is angled the right way so that this doesn't fall off. There's only like maybe a certain amount that you can move your screen backwards and forwards before this may fall off. So don't go too far back. I would say just keep it at maximum. Let's do a distance test. And of course, if you are looking down on your screen, then I would say maybe no further than that just to keep it secure. You don't want to damage your phone. I'll just move it back up a little bit. Here we go. And now you can use this with phase time with zoom. It just pops up automatically on your video settings as your iPhone camera. So you can just switch it very easily. Two ways to use it. First of all, you need to make sure that the phone is locked and it is in a horizontal view like this. That's the only way it will pop up as a continuity camera. And secondly, you need to make sure you have iOS 16 on your iPhone or higher. And you also need to have Mac OS Ventura, i.e. 13.0 or higher. Without those two, if you have any of them that's lower versions than that, then this will not work for continuity camera. So just keep that in mind. So let's go ahead and open up a zoom call. Okay, so right now this is using the internal phase time HD webcam on my MacBook Pro. So what I'm going to do is now switch over to my iPhone camera, which you can see is there selectable. Look at the difference in this quality. Using the back main lens on this, it's so clear and it's probably the highest quality webcam you're going to get on the market if you're able to use your phone like this. It was so quick and easy to do that. And once I start using this as my webcam to do all of my meeting calls, then I know people on the other end are going to be so shocked at how clear my quality is on my webcam. I think this is just perfect to have. And to be honest, this Belkin mount, they've done an excellent job. There's a lot of third party ones that claim they are MagSafe phone compatible webcam mounts and all this kind of thing. But I don't think any of them are going to be as high of a quality as this one. One of the other things I wanted to show with the continuity camera is the other features that come with it. If you open up the control center from the top, you go to video effects. You can actually switch between center stage, portrait and studio light. Let me quickly show you this. So center stage, it'll kind of keep you in center if you are moving around, which I think is great. If you switch to portrait mode, I'm going to turn off center stage. It just blurs the background a little bit, which is a very nice bokeh effect. It's very smooth. And it does a very good job, to be honest. And if you turn that off and go to studio light, it just kind of dims the background a little bit, focuses more highlights onto yourself. And it just makes yourself a little bit clearer. So it depends on the lighting in the room if you want to use that. And finally, one of the coolest things, it will switch to the ultra wide view camera is if you switch to desk view. And it kind of does like an unboxing top down shot. Let's click on that. So you can actually set where you would like this to be. So I'm just going to move this back slightly. You can just reduce the size of that. I'm going to align it perfectly there to my desk. Hit start at desk view and look at that. Of course, it does stretch a little bit. If you wanted to maybe read the text, it might not be so great. But if you just wanted to show people quickly and maybe you wanted to use this for shooting some videos to show what's on your desk, what you want to do. This may not be like the best way to do it. I don't think the quality is so great on the desk view. I think the idea that they have of implementing something like this is quite nice. But I don't think it's made to perfection just yet. There's going to be various different iterations to this. It's not something I would use. I would always have a top-down shooting rig to maybe shoot something like this. But I just wanted to really showcase to you guys how this would look. If you wanted to show anything which has text on it, then I don't know if that would actually be so readable to the users. But nonetheless, it's there as a nice feature or a quick way to show simultaneously while you are being seen with the main camera what you want to show on your desk. So not too bad. Overall, I think the Belkin mount itself, which is what I'm reviewing today, is an excellent mount. And I actually think it is worth buying. And for less than 30 pounds, normally with the Belkin products once they are selling on the Apple website, they do come out a little bit more expensive than generally I would pay for. But I think this is very nicely priced. And if you are looking to maybe use your phone as a webcam, you have iOS 16 or higher and you do have Mac OS adventurer, then for me personally, this is a must have accessory to have with you on your desk or in your office as well. Final thing, let's go ahead and test this with a heavy duty, non-Apple certified MagSafe case on that just to see if it holds and is strong enough to do that. And last thing to mention, it doesn't necessarily have to be mounted on top. You can even just have it to the side. You can have it this way. And to be honest, it can be at quite a distance. They say it has to be quite close to your MacBook for it to work.  I'm actually about five meters away from the MacBook and it's still working. I actually didn't know this. So this is quite a nice surprise. So in fact, you don't even need to be so close to your MacBook. You can even just walk around and just use your phone in your hand and showcase people like other things in the room maybe. I just found that out now. I didn't realize that before. I think that's really convenient. I don't necessarily have to be exactly mounted on my MacBook. So not too bad. So you can actually be a bit more versatile, be more flexible and move around with this. Okay, I now have my iPhone case. It may look like an official MagSafe case, but in fact, it's not. It's just the third party one that I got from Amazon. And even then the magnetic hold on this is super strong. It's just like without using the case at all. Quick pop on there and you're ready to go. So it works in all scenarios. I'm very happy with this. There's not much more else I can say. I do recommend this. If you really like to use your phone as a webcam, must have, check it out. Link is in the description. If there's anything you guys want to know about this Belkin mount, then drop a comment down below. If you like this review and you like all things related to iPhone, I have new videos out all the time. I review tech and gadgets every week as well. So make sure to subscribe so you don't miss any of those videos. And I will catch you guys at the next one. Take care.


Hello and welcome back to the Sports Biomechanics Lecture Series as always supported by the International Society of Biomechanics in Sports and kindly sponsored by Vicon. Again, as always all views are those of the individual speakers, but today we've got a speaker and some views that I'm really looking forward to hearing. I know some other people are as well. I think when I first set up this series, one of the main goals was to try and help as many biomechanists as possible, ranging from students through to researchers. And hopefully with the topic today, it's something that will benefit quite a broad range of people. So, without further ado, I'm joined by Professor Bill Balzopoulos, who is head of the Research Institute for Sport and Exercise Sciences at Liverpool John Bowles University. His main research interests and work are focused on the biomechanics of the musculoskeletal system. Today, he's going to give a talk on a really common area within biomechanics, where there are a lot of kind of potential misconceptions. So it could be really good to try and clarify those and maybe add in a little common sense to the situation. So he's going to give a talk on inverse dynamics, joint reaction forces and loading in the musculoskeletal system with various mechanical misconceptions. So thank you very much. And over to you, Bill. Thank you very much. And hello everyone. I hope you're all well. Thank you for tuning in either live or watching this recording later. Thank you very much for the introduction and your kind words, Stuart. And I can assure all people watching that I am the same person as the Sport Biomechanics lecture series flyer that Stuart circulated. This lecture was from a long time ago. But thank you for all your hard work and therefore Stuart it's really appreciated it's an excellent initiative, especially in these strange and difficult times. And thank you also to ISBS and Viking for supporting and contributing to this work. And briefly explained in this lecture I just want to address some important issues in my view linked to inverse dynamics musculoskeletal loading and related terminology. Now I appreciate that this is perhaps a dry technical subjects and perhaps not not as interesting or exciting as the other more applied sessions. Yes, I believe that it is very important as it underpins most of the other work that we do and we must all understand and communicate with the same mechanical language. So, the session hopefully will satisfy everyone. It's a little bit difficult to plan when you don't really know the experience of the audience. So I try to balance the talk. And I'm going to start with some basic principles were needed so that we all understand the same things. I also included a basic modeling example, just to make some points. So, I hope you excuse me for sort of following a rather simplistic approach to make some some points, but I'm just going to start with some general aspects about the assessment of loading. Just concentrate on, as I said, some basic steps I'm also going to go back to some seminal papers in this respect because I think this is very important. And then I'm going to concentrate on just the main steps of inverse dynamics. And in my view, why some mechanical misconceptions have crept in over the years, and are not very helpful in my experience. And I'm just going to end up with some conclusions and recommendations for the way forward in my view. I think by mechanics. Just a big picture, the work that all of us are doing are basically either to improve performance or training or to prevent injuries. So I'm sure we all want to help athletes achieve great results. So in the process, trying to avoid injuries. Now, whether we want to improve performance or prevent injury, we are interested in forces in biomechanics that's why we obsessed with understanding the effects of the forces, and spend a lot of time trying to use forces either to improve performance or understand the effects on biological tissues. But the problem of course is that forces are not visible. We can only see their effects, because we can't directly measure them. So, obviously, there's a broken tibia there with a clean fracture. So that's clearly the effect of some overload, a force that was applied. So the only thing that we can do is to measure the effects of the forces on the musculoskeletal system. And these effects are usually deformation in the tissue or some tissue strain. Now, it is actually possible to measure in vivo the effects of forces, that is to say, what deformation or strain they cause in tissues in vivo. However, this is a special sort of tensiometry that's been developed. What obviously instrumented prosthesis or some strain or optical transducers that can be implanted in the tissues. And you have some really nice pictures there of the work that was by me by Taya Fini and Paavo Komi assessing the strain of the patella, but also the Achilles tendon using optical fibers. So the optical fiber goes through the tendon, and obviously as the tendon develops force and the strain is changed, the quantity of light that goes through the fiber is calibrated to determine the force or to reflect the force that goes through the tendon. There's a lot of other methods that have been developed over the years for the assessment of loading in the musculoskeletal system by somehow assessing the in vivo tissue strain. So I'm just going to go through some of these techniques. I don't want to spend a lot of time. It's just an indication of how using some of these invasive techniques, we can actually have some estimation or direct measurement of the strain in tissues. If we look at tendons, again, there've been techniques that use ultrasound, for example. This is the paper, seminal paper in my view that Costis Maganaris did with Professor Paul. In this particular one, they measured the mechanical properties of the tibialis anterior tendon, and just by tracking my tendon's junction of the tendon, they were able to, in essence, measure the strain in the tendon, and with some measurement based on the measurement of moment time, they were able to relate that displacement of the tendon or the tendon strain, if you like, to the stress of the tendon. More recently, obviously, Daryl Fellen and his group presented some amazing new techniques that rely on shear wave tensiometry. So just by tapping the tendon and measuring the speed with which the waves sort of travel through the tendon, either initially through ultrasound or with some accelerometers. They're able, as you can see, to relate the speed with which the waves are travelling through the tendon with the torque, because obviously the speed will be proportional to the strain in the tendon. Some really, really exciting ideas that basically allows you to, with this external device, measure the wave speed, and as you can see here, the Achilles wave speed squared is following very nicely the ankle torque developed during GATE. So again, very exciting and promising recent techniques. A little bit further, we can see that you can actually look at ACL strain. We're doing a lot of work and a lot of people are interested in preventing ACL injuries. And it actually, it is possible, obviously, under very restricted conditions to implant a transducer and the work of Bruce Payne in the 90s. They've started with a whole effect transducer, but this is an improved method. And you can see here that obviously in these conditions, you can see the ACL strain in different flexion extension examples in the knee. These days, a similar idea for the ACL strain, but based on biplane x-rays. So this work is using high resolution CT3D image. And obviously, if you identify the proximal and distal ends of the Achilles, sorry, the anterior cruciate ligament, these points can be tracked in real time during the movement from the x-rays. And obviously, you can measure the 3D distance between the attachment sites of the ligament. And therefore calculate the lengthening of the ligament in this case during walking and running. Again, under x-rays, there are restrictions, but very promising techniques to be able to look at the different strains in this case, not only of the whole ligament, but the different bundles of the ligament as well. A different group. This is Louis De Freight's group, obviously, based on MRIs this time. So the 3D model is based on MRI, but again, if you know the location of the attachment in the femur and the tibia, then those can be tracked in real time with the x-ray system during the movement. And again, you can see approximately 7% maximum strain in the ACL. Again, very promising techniques. And the last piece, I don't know whether you were in the CAMHS NE workshop that Bill Taylor organized in February, but again, some pioneering and excellent work using the data at the Tarete Hospital and the Eulens Wolf Institute together with Gail Bergman, the pioneering work of Gail and Gail Duda now, and obviously Bill did also some pioneering work tracking ACL with bi-planar x-rays, but this is an exciting development, but again allows the assessment of loads directly using these instrumented prostheses. To measure in vivo effects of forces in tissues, but they require highly specialized techniques that have various problems. There's obviously ethical issues either with invasive techniques or x-rays and ionizing radiation, although the dosage is quite low these days. There's obviously infection complications if you have invasive techniques. There's clearly disruption of normal movement, there's only restricted movements that you can perform under these conditions and restricted activities. Obviously if someone is having an instrumented knee prosthesis, they're unlikely to be able to perform perhaps highly dynamic movement that might be injured in sports biomechanics, and obviously there are various calibration problems. So just a quick introduction and of course the alternative and given that we're talking about inverse dynamics, the alternative to all those direct in vivo methods is of course to use biomechanical models. So whether we use a rigid body model or a more complex model, modeling is an attempt to represent reality in a simplified way. So if I was interested in what joint moments are exerted in a person that is performing a vertical jump, then obviously I can use a simplified model or a more complex muscle skeletal model. So I just want to spend a little bit of time on the basics of this process because I think that's where most of the problems start. And the question that I will follow, obviously there are a lot of different ways to classify biomechanical models. But the type of classification that I'm going to use here is basically divide models to either conceptual, statistical or regression models or full mathematical sometimes also called computer models. And if we look at sort of a graphical representation of those models, I'm not going to talk about at all about sort of hierarchical or conceptual models of technique or regression models that we sort of measure a lot of parameters and we're trying to sort of fit relationship to those. But I'm just to concentrate on the types of models where we represent the human body with a rigid segment and using the equations of motion, we're trying to understand something about the forces that either cause the movement or loaded the various tissues. I'm not going to go into detail into highly complex three dimensional musculoskeletal models. I'm just going to show you some brief output of the work that we do. But for this lecture I want to concentrate on simple models because I want to, as I said, explain some principles with very basic examples that you can probably do by hand. In Liverpool John Moores University we have a big osteoarthritis project, the o-active projects and in fact we apply quite complex techniques to understand multi-scale effects of forces. So we might start with joint angles and kinematics in the body, we then try and determine internal joint loads and muscle forces but we then also apply these to finite element models of the menisci and the ligaments and cartilage in the knee to understand cartilage stresses in people that don't have osteoarthritis and those that develop osteoarthritis. Obviously the complexity is increased dramatically if you try and understand the stresses in various tissues but obviously the clinical relevance is also increasing because this type of information is very important for a clinician. And as I said a lot of this, although this is a clinical application and not a sport application, similar techniques can be applied in sport. So we use a pipeline using the open sim system using motion analysis of normal gait and people with osteoarthritis and using this pipeline we can calculate knee joint loading but also if we have MRI or CT scans from patients then we can also combine the kinematics with the finite element model that was developed from the segmentation of the MRIs and that provides the stresses in cartilage and tissues in the knee. But for this talk what I wanted to separate is the concept of running inverse dynamics techniques and that provides us with the joint moments and only the partial joint reaction forces and obviously in a complex system like this when you have many muscles the knee joint moment calculated will be originating by the activation of a number of muscles and the forces produced by a lot of different muscles. So through static optimization we calculate the individual muscle forces and then with some force system analysis we calculate the total joint reaction forces. But what I wanted to stress here is that to arrive at the point where somebody can calculate the actual joint reaction forces having calculated muscle forces you need to go through inverse dynamics first. And that allows us to as I said calculate cartilage just a quick example here that shows that a healthy person the stresses are distributed both on the lateral and the medial side. But if you see with as you progress through early way or develop to osteoarthritis, then the stresses, especially in the medial side tend to be concentrating on a much smaller area. Again, an example of multi-scale modeling and how you progress from inverse dynamics to cartilage stresses in specific tissues. But generally speaking, the procedures, the general procedures in modeling follow all these steps. And I'm using the example here from Beno Nigs and Walter Herzog's book, which I think is very clear in these issues. And you can see that irrespective of the type of model that you need to use, whether whether it's a regression model or a rigid body model or even a more complex three-dimensional muscle sleepy model, you have to go through these general steps. And one of the questions that you might want to ask, for example, is what is the loading the need during weight training? And according to these general modeling procedures, you need to start thinking about what part of the body do I need to model? What I need to know about the way the forces are applied by muscles and tendons in this movement and what kind of model will be appropriate, but as simple as possible. In other words, can a two-dimensional rigid model of lower leg will be sufficient or do I need to go to a full three-dimensional musculoskeletal model? Now, again, I'm going back to one of the first papers that applied and explain the application of inverse dynamics in biomechanics using free-bodied diagrams. And if you look at these papers, the process, the general modeling processes applied to the analysis of forces using a free-bodied diagram, obviously you have to look at the system of interest for the research question. We always have to start with a relevant research question and then see what type of model would be appropriate, but once you decide that you still need to do some assumptions and simplifications. You said a model is an attempt to represent reality, so you have to accept that you're going to perform some or accept some assumptions and make some simplifications to be able to do that. And then you're ready to build the free-bodied diagram, which is basically a depiction of the rigid body, the reference frame and all the external forces and moments acting on the body. And what kind of forces are we talking about? Generally speaking, and again you can go back to the original references, there are just two types of forces that you need to think about in applying in a free-bodied diagram. There are more forces that are applied without any contact and in biomechanics, we're basically talking about the weight, which we normally apply at the center of gravity and contact forces. In other words, forces that are applied on your segment on your free-bodied diagram of the segment through some sort of contact. And these contact forces are described as two types. If you go back to the paper by Andrews, for example, he just clearly states all we need is contact forces at the proximal and distal joints and these are because of the contact with other segments in the kinetic chain or contact forces on the free-bodied diagram between the joints. So in the beginning, in the very beginning, there was no other sort of terminology used, it was either remote or contact forces. And then obviously if you have those forces applied, you develop the equations of motion depending on the complexity of the model, and then you just solve the equations of motion to calculate the various mechanical parameters that you need. And this is an example from the Andrews paper for three dimensions and two dimensions as well. I just want to again make the point that what we're talking about here is either contact forces at the proximal and distal joints and contact forces in between. Anywhere in between in addition to the remotely applied weight force vector. So when we're talking about inverse, what does the term inverse mean? What exactly is inverted in inverse dynamics? I started up on a six when you pulled through the clouds and then I moved in above them. Well, if you were directly above him, how could you see him? Because I was inverted. I don't know whether you're a top gun fan, like myself, but the new top gun movies coming out while he was coming out this July, hopefully that won't be delayed. So basically what we're talking about is not being upside down. What we're talking about is using the equations of motion for a simple two dimensional model here, but in the inverse sense, that is to say, we start with a movement. And if we calculate the kinematics of the movement, then we can use the equations of motion to determine the forces or the total force that cause that movement and then obviously that can give us the loading. Again, remember that the only forces that we're talking about are either contact forces at the joints and contact forces anywhere else on the free body diagram. There are also questions such as what is the loading in the ligaments, for example, during this exercise or what is the loading in the different joints. If I calculate the total joint moment, if I, if I calculate forces in a certain direction. So if I look at a very specific example that you can probably do by hand, I just want to do a very simple knee extension exercise. Just imagine that a person is just holding the lower leg in a horizontal position. So they only have to overcome the weight of the lower leg segment and the keeping the leg in this position. For this example, I'm just going to assume that the horizontal axis is aligned with a compressive or the long axis of the segment and the vertical axis, the y axis is is aligned with the shear axis of the segment. So there's the rigid body depiction. I put my reference frame system, I assume that these are the positive directions in the compressive and shear or the x and y, if you like. And then I apply the external forces and moments, as we said, there's the remote force of the weight and then the joint contact forces. We don't have a distal joint here. We assume that this is the last, the terminal segment in the kinetic chain. So I just apply two forces compressive and the shear component in the proximal joint. And these are the joint reactions, because this segment obviously has contact with the upper leg at the knee joint here. When I'm coming to draw the contact forces on the free body diagram, we basically have two options and we can follow two different approaches. You can either draw those forces as they act. And this is what Nick calls actual forces approach in the Megan heads book, which is very clear on this subject, or you can use what's called the equivalent moment and force. So instead of applying the forces as they act, you just apply a resultant moment and force at a suitable position. And normally this is is the origin or the joint point through which the axis of rotation is supposed to act. Again, the only terms that we use is contact forces and for this category of forces in the free body diagram, I need to make this choice. If I want to apply the forces as they act, then obviously I need to have that information, and we can either get this information from the literature. So for example, if I want to know how is the patella tendon acting on in this example, then I can look in the literature we have done a lot of work on this subject. So you can see here that we can measure the knee joint kinematics using x rays. And in this picture you can see that I can almost faintly make the outline of the patella tendon. So I can see how the tendon, the patella tendon is attached. So how the quadriceps force will be applied in relation, for example, to the TBL plateau. So here's the x-ray. I hope that will show play on the video. So, okay, the video is clearly doesn't play, but I'll basically explain here that with the x-ray we can actually determine the orientation of the patella tendon relative to the TBL plateau, which happens to be our shear axis in the joint. Because obviously that will be important information if we wanted to model this. So this is from the work of Demetriopoulos PhD. So if I want to go in passive conditions or in contraction conditions, obviously if I'm just holding my weight there will be somewhere in between here. And I can see that near full extension angle would be just over 120 degrees. So I can get this type of information to model the way the muscle force is acting here. To have this information I can also assume that there will be a joint moment exerted by the muscle force, although I don't have information to model the force as it acts. I can just replace it with a moment and some force that will simply change the overall compressive and shear components of the contact forces at the joint. So if I apply the equations of motion, then I can solve them to calculate those contact forces and either the moment or the force that is applied here. So here's the equations of motion for this simple example. Obviously we can only have one unknown muscle moment and one unknown force for each equation, otherwise we won't be able to solve these equations. I'll talk about this a little bit later the system will be indeterminate. But if there's only one unknown force acting, all the others are known. So I can sequentially first calculate the overall joint moment and then again sequentially go to the compressive direction and apply the equations of motion to calculate the overall reaction force in the compressive direction and do the same for the shear direction. What I want to make here is that whether I'm using a very simple two dimensional free body diagram that I can do the calculations by hand, or whether I'm using a very complex three dimensional musculoskeletal model. So these are the two processes of determining the free body diagram and all the forces acting and all the muscles. This is musculoskeletal modeling aspects that we have to go through irrespective of the complexity of the model. If I see those two examples, we can see here what is called the resultant moments approach or the actual forces approach, and you can see that the equations of motion are almost identical. And the only thing that will be changing obviously is that the number of forces that you will have in a resultant moments approach will be different to the number of forces that you will have where you apply the actual forces. So the only difference is to be different. So normally the maximum number of forces in the compressive direction will be less than the maximum number of forces in the compressive direction in this approach. So here's the detailed expanded form of these general equations. And as you can see, you can probably solve these by hand, but it's an important point here to make, and is that both approaches are mechanically equivalent. So I can examine this simple near extension example using either this set of equation or this set of equation. And the mechanical behavior will be equivalent. That is to say, the mechanical system motion will be exactly the same whether I apply this set of equations or this set of equations. And the other point to make is that the inverse dynamics output is always the forces that are applied or the unknown moment and the two reaction forces. So the equivalent of the of the reaction force in the X and Y direction, although they're normally initially drone generically to point towards the positive direction. Obviously the calculations will will give us the actual reaction forces in the way they act that is to say, if the RY calculated is negative it means that it's actually acting in the negative direction. So these calculations and again I sort of kept that simple so that we can do these calculations by hand. And as you can see, if I follow the actual forces approach, I will come up with the answer that the muscle force applied. So obviously the moment arm. Then the muscle force is 243 Newtons. And you can see that the compressive force is 225 Newtons in this example, as shown here, where's the shear force the component of the reaction force, or the joint contact force is minus which means that in this example it will be acting along the negative direction, whereas with the resultant moments approach. Again, I calculate the overall joint moment in this case, and the RX and RY in this case they have different values. So no compressive force and the shear force or the component along the Y axis or the shear direction is positive in this case, meaning that it's acting in the positive direction. So you can see that there's already some differences depending on the complexity of the model and the approach that we take in modeling the way the forces, the one category of contact forces the contact forces in between the joints are applied. The important thing here is that this information say if I look at the actual forces example. So I've drawn here roughly to scale the compressive and the shear force. And what we can see is that this information, if I think of the model of the free body diagram, it tells me that there is a force applied in this direction, and obviously an external the other segment that is attached to this segment, the ligament that can create a force in this direction, mainly, obviously there's other tissues, but it's mainly the anterior cruciate ligament. So with this information, I can start getting some assessment if you like, or some idea of what are the ligaments that are likely to be loaded in the joint. If I was following this simple example. Obviously, this will give me a completely different answer because this will probably indicate that is actually the posterior cruciate ligament that is loaded. So you can see that I can get a different answer, depending on how I model the forces and which inverse dynamics approach I'm following here. This is an excellent paper recently to present a sort of a similar more generic example that makes these points. I think the inverse dynamics. Nomenclature that is recommended. In my view, sort of reproduces some concepts that have been introduced over the years, and Andrew has done a very good job in sort of summarizing the different technology in a magnitude that is applied to classifying the different aspects, if you like, of joint forces. But as you can see here, the situation, if you look at the literature is quite complex, was if you go back to the way the free body diagram was originally described, you only had two types of forces, remote and contact forces, and just two categories of contact forces was here we start seeing that over the years, we have things such as resultant joint force, bone on bone forces, or net joint forces. And in my view, that attempt to sort of make things perhaps more complex goes in the other direction, whereas I think we should be keeping things simple, and trying to simplify the way we apply inverse dynamics. There's another very good recent paper by team and collaborators. In fact, we wanted to discuss these issues with Alberto in the ISPS conference. But again, you can see here that there are concepts about intersegmental forces, net forces, resultant forces, and so forth. So, my view is that we started in the 1960s with some sort of seminal papers by Andrews or Paul, for example, in his paper in 1966 about hip joint loading, and the only term was joint contact forces. And here we are in 2020, and we have this classification of sort of put this information from Andrews paper, but I've added their own suggestions and also the ISP recommendations. And you can see, for example, that some of these sort of appear on both sides of the table if you like. So somebody might be calling this joint reaction force, and somebody might be calling this joint reaction force. So although there was a great development of technology in biomechanics over these years, I think the terminology actually is a retrograde step. And perhaps, if you like me, you probably think that it's probably a situation with the tariff bubble than making things more clear. So I think my view is that we need to simplify this. This is not helping this classification is not helping the work that we do. And I just wanted to sort of follow some arguments. So let's say that I was applying the actual force, and then I also was able to estimate how much the antagonist force was. So using a model applying the antagonist force in this example. It is possible to do this we've done it before. Another of other groups have done it before. If you use an EMG force model during the flexion, then you should be able to apply the flexor antagonist force during the extension. So the question here is, is this calculation, the joint reaction force will be obviously different, because it'll probably reduce the shear load and increase the compressive load. But is this another category or another flavor of the joint reaction force? In my view, that's not the case. The joint reaction forces are only one set. And in the same way as we have ground reaction forces in the terminal segment, we should only be talking about these contact forces at the joint and calling them joint reaction forces. And the magnitude and direction would depend on the complexity of the model. It's not a sort of a dual system, depending on the complexity and the approach that we use. The overall joint reaction force will have a different magnitude and direction and obviously the components in the two different axes will be different, but it's one and the same joint reaction force in the context of the free body diagram. So my view is that all these terms net joint forces or resultant joint forces or intersegmental joint forces are inappropriate for differentiating joint reaction forces if we use an actual forces approach or resultant moments approach, because a net or resultant simply means that is the vector sum of something. And if you look at this diagram, what we're actually doing is that if I calculate the net of all the forces applied on this free body diagram, the net or resultant is actually applied on the next segment. So all the forces applied on the lower leg have a net force that is actually applied on the upper segment. But what happens to this upper leg segment is of no interest to me when I'm analyzing the lower leg. And what I'm interested in is the reaction of the net force that is applied on this segment by the the other segment. So what I'm calculating is actually the reaction to the net force of all the forces applied in the lower leg. So irrespective of the approach, the joint reaction forces will be net and resultant so I can use those two to differentiate. And obviously intersegmental means that is acting between or across segments. And as I explained, the reaction force is obviously applied because of the application of the net force to the other segment. So the reason that we can't, in my view, differentiate with these terms is that I said the components of the reaction force are net or resultant and intersegmental irrespective of the approach used. That is to say Rx and Ry either in this approach or that approach can be described as net resultant and intersegmental. So I shouldn't be using these terms to differentiate those two. There's also another example of supposedly the existence of the bone and bone force that is different to the joint reaction force. And in various books not only in winter. I mean this is a great book, but this sort of concept has been reproduced in another of biomechanics books to supposedly describe the existence of the bone and bone force that is different to the joint reaction force. However, in my view, this is not a rational argument. And in fact is a flawed foundational premise to support the existence of a different category of force that is called bone and bone force. What is actually being described as a joint reaction force that's different to this bone and bone and bone force is in fact a joint reaction force that was incorrectly calculated because if you say that there's a difference between a relaxed segment or when somebody is contracting the muscles, then what you're saying is that I know that there's some forces acting, but I'm not going to bother including them in the free body diagram. Well, obviously, if you know that there's forces acting and you don't include them, then the joint reaction force that you will calculate will be wrong. But that's not a reason to say that there's a bone and bone force that is different to the joint reaction force. What is actually described as a bone and bone force is the correct joint reaction force that you will calculate if you included those forces. Now obviously, that's technically might be challenging but as I said, even if you calculated the force of one of them or estimated, then the inverse dynamics will predict the other one and will calculate the correct joint reaction force. In conclusion, in inverse dynamics, free body diagrams include the actual forces either as applied or as equivalent resultant force and moments, and these lead to those two different approaches. But irrespective of the approach used, the inverse dynamics output always include the joint reaction forces representing the interactions with the adjacent segments. Although the resultant moments approach is very convenient because you can use it to model a multi-segment system so do multi-body inverse dynamics because you don't have to worry about modelling the forces in different joints. They avoid indeterminate systems because you always have only one unknown in each segment. But the joint reaction force calculated is only the partial joint contact force because it does not contain the contribution from muscles and other internal joints. As I said, it's very convenient in inverse dynamics these days. After all, if you're interested in the loading in the hip joint, there's no point calculating in detail how the muscles are acting around the ankle. You can easily use resultant moments approach in the foot and move up the kinetic chain and then just do a more detailed analysis when you arrive at the hip joint. If you're interested in the total joint reaction force, in other words, the total joint load, you have to make the effort to apply the muscle forces in particular as they act. As I explained, all the other terms that are suggested are inappropriate in my view because whether the joint reaction force is calculated from the actual forces or the resultant moments can be described by all those terms. So I just want to dispel some myths and misconceptions in my view. There are no different flavors of joint forces. There's only a single joint contact force calculated from the inverse dynamics, but obviously its magnitude and direction will depend on the complexity of the musculoskeletal model and the inverse dynamics approach that was implemented. And musculoskeletal modeling is always required in inverse dynamics, irrespective of the approach that you use and the complexity of the model that you implement. And the last point that I want to make is that there's normally an accusation that all these misconceptions and inappropriate terminology are linked to sport or sport science or sports biomechanics only, but I just want to make it clear that in my view, these terminology issues and misconception crept through other areas and not exclusive or certainly not originated in sports biomechanics. So I'll leave you with some guidelines and recommendations in my view again for using accurate terminology for inverse dynamics. You should always report the inverse dynamics approach used and whether you use an actual forces approach or a resultant moments approach. The joint reaction forces. If you use the resultant moments approach are only partial joint reaction or contact forces, you should not be using those to determine joint loading. And as I said, all these terms, in my view are inappropriate, because they can be inappropriate to distinguish joint reaction forces, because they relate to the calculated joint reaction forces irrespective of the inverse dynamics approach used to calculate them. And if you want to calculate accurately the joint loading, then you need to somehow determine the muscle forces and the way they act. So joint reaction forces from resultant moments should not be used for joint loading estimation. Again, if I go back to the way, an example from the active project. Again, although we calculate the partial joint reaction forces here through static optimization in this case because it's a very complex model we're able to calculate the muscle forces, and then through a four system analysis basically the actual way of applying the forces were able to calculate the total joint reaction force and then apply this force to the finite element models. So, if it was up to me, my suggestion for inverse dynamics is instead of having a complex table is simply to state the inverse dynamics approach that you use, and just refer to these joint reaction forces if you use the resultant as partial joint reaction forces was if you made the effort, either through simplification and just including one muscle force or through optimization and calculating the muscle, all the muscle forces acting is to refer this to total joint reaction force. Thank you very much for tuning in. Thanks, Bill. That was brilliant. And yeah, firstly, I love the top gun reference. But yeah, I think I'm massively in favor of anything that simplifies either terminology or application and I love that you brought it all together at the end of a series of really clear and concise recommendations is basically just saying, we have to state whether we're using an actual forces approach or a resultant moments approach, and we have to state whether we're using total or partial joint reaction forces. And I think when you can sum it up in a really simple and clear message, but actually have all of the kind of theory and justification behind it to support those recommendations. And yeah, I thought that was brilliant. Thank you. Thank you very much. Yeah, I think the only kind of real question for me as a follow up to that was, could you give any examples of potential problems that can occur as a result of people using the wrong terminology. There are there are several examples and again, if you look at Andrews paper, we've got to tell paper that they cite various examples where people basically in essence they use the resultant moments approach. And this is this is the typical approach that you would use in a multi segment inverse dynamics, especially with a musculoskeletal modeling software. And initially you have to calculate the joint moments, and the joint reaction forces that you calculate from, from this part of the inverse dynamics process, as I explained, are only the partial joint contact forces or the partial joint reaction forces. And you can't, you can't use that system that that calculation to start making inferences about what would be the load in the different tissues, such as the cartilage for example or the cruciate ligaments and so forth. I think I think there's numerous examples of papers, as listed in Andrews said, of applications where people are using a partially calculated joint reaction force to make inferences about the joint loading, and that is the point that we shouldn't be doing this. And obviously, if the interest is only on the joint moment, then you can stop at that stage. And because the joint moment will be accurately asked and say, you know, the joint moments was such and such and that's how the joint moment is attributed in the, in the joints of the low limbs, for example. But if you wanted to go any deeper and calculate loading in the ligaments or the cartilage, then you need to make sure that the joint reaction force, which again is the only output in terms of forces in the joint from the inverse dynamics approach that that is the force that be related to the actual loading in the various tissues around the joint. So that that that is the point. Thanks. I think, yeah, again, another set of kind of really elegantly expressed but clear and concise recommendations. I think again it comes back to that general point we always go back to of your methods stemming from your actual research question. And what are you actually trying to work out. Is it the joint moment or is it loading in cartilage or ligaments and then your methods have to apply to that. Yeah, and one of the things that for example, that is clear is that if we look at the terminal segment, we all we all understand that, you know, you have the action to the ground and then you have the reaction from the ground to the segment. And we happy to sort of just call this the ground, the ground reaction force.  You know, we're all we all understand that it's the reaction to the force that we apply to the ground. And it should be the same on the other side, you know, with the proximal joint. We're looking at that segment at that point in time. And it's the reaction from the other segment that is applied on the segment we're analyzing and therefore it's a reaction force at the joint and therefore it's a joint reaction force. I think we should just stick with a joint reaction force and whether it's the partial or the total depending on the complexity of the musculoskeletal model and avoid any other misleading terms in my view that sort of are not helpful in trying to sort of discuss issues about loading in the musculoskeletal system. Yeah, perfect and clearer, more concise and more simplistic is always beneficial for everyone. Yeah, I think to have got a comment on YouTube I think sums up sums that up perfectly. So, for pronounces right Athanasios Visas says, thanks Bill that was great, in particular the clear recommendations we need as a scientific community to clarify these issues and move forward using the same conventions. I think that sums up perfectly both what you've said and what I feel Sahel is. And I think sometimes it's also important to be going to some of these, you know, older but seminal papers because I think the crystal clear crystal clear. I'm sorry my, and the terminology is unambiguous and very very clear. Yeah, agreed and if anyone is interested in any of the papers mentioned especially the more seminal articles. There are links below the video on YouTube to most of the papers mentioned in the talk, and then the others there's a full reference there as well. So hopefully encourage some more kind of wider follow up reading as well. And then, but yes on that I think all the remains really is just for me a huge thank you to Bill because I've said that was really really excellent and useful for a lot of people, and just to people watching and don't forget that all of the previous lectures are available to view on the same channel and keep an eye out for lectures in the coming weeks on tennis biomechanics and bit more a practical based guide or session from Vicon on various things relating to motion capture. Yeah, thanks again Bill. Thank you very much and thank you all for watching.


Hello, I'm Dr. John Loftus. I'm an anesthesiologist and the physician-in-chief. It's my pleasure to welcome you to the Kaiser Permanente Oakland Medical Center. As physician-in-chief, I'm responsible for the medical care delivered in this hospital. Here in our state-of-the-art facility, we perform over 13,000 surgical procedures every year. It's our goal to make each of our surgery patients and their loved ones feel comfortable, informed, and well taken care of. This video will give you an overview of what you can expect with most surgical experiences. Hi there, my name is Olithia O'Toole and I'm a Kaiser Permanente member. I've had surgery here before, so let me give you a few tips. Wear loose-fitting clothing, leave valuables at home, and please follow the eating and drinking guidelines you were given so your surgery can proceed as planned. Once you arrive to the hospital, you'll find there are a few parking lots close by. The main one used by patients is adjacent to the hospital with the entrance on Broadway. Unfortunately, the city of Oakland requires that we charge our patients for parking, although we wish we could provide this for free. When you enter the medical center, you'll walk past the information desk. Halfway down the hall, you'll see the elevators. Take those to the second floor. This is where you'll check in. Please arrive at the time you're given so that your care team can adequately prepare you for surgery. When you get to the second floor, you'll need your Kaiser Permanente card and a photo ID. You'll need to register by completing some paperwork. And here's a copy of your consent. Okay. Hi, my name is Brooke Bennett and I'm a registered nurse in Pre-Op. This is the area where we'll get you ready for your surgery. Hi, Ms. Wallace. Hi.  Your family and friends will stay in the waiting room, but don't worry, you'll have another chance to see them before surgery. The first step is having you change into a hospital gown. This is also a great chance to use the restroom. Hi again. Hi. Next is for us to take a private history with you. We'll do some routine care, including taking your vital signs and getting your weight. After that, we'll get your IV started and draw any necessary labs. You'll get any medications that your surgical team has ordered. At this point, family members or friends can join you if you'd like. If you didn't lock up your valuables at registration, we'll do that for you now, unless you want your family or friends to hold them for you. The last thing you'll do in Pre-Op is meet the team who'll be taking care of you. Morning, sir. Your surgeon, anesthesiologist, or nurse anesthetist, and your OR nurse. They'll go over the surgical plan and give you an opportunity to ask questions or clarify issues. And your medical record number is... Throughout this whole experience, prior to surgery, expect to be asked multiple times your name, Kaiser Permanente number, date of birth, and what procedure you're here for. This is an important safety check for us. Hi. My name is Glenn Valenzuela, and I'm one of the anesthesia providers here at the Oakland Medical Center. After Pre-Op, you'll be taken back to the operating room where your surgical team will be waiting for you. They'll be wearing caps and masks to keep your OR suites sterile. It's normal for the room to feel cold. This helps with sterility. You'll be assisted onto the OR table where you'll be attached to heart and lung monitors and stockings to squeeze your legs. These help with circulation. The team will review the consent with you and with each other. This is Missy Wallace? That's correct. Okay, she's here for a diagnostic laparoscopy, possible open.  My name is Linda Jordan. I'm your OR tech. Okay, my name is Glenn Valenzuela. I'm the anesthesiologist. She's gonna get a general anesthetic. She will receive two grams of Ansaft before incision. This is done as a final safety check and sets expectations for the surgical team. Once we're all in agreement, the next step is to get you safely off to sleep. You can hold my hand while you go to sleep, okay? Family and friends can follow your progress on the surgery board in the waiting area. We'll give them a color-coded chart so they'll know how to read the information. When the surgery is finished, your surgeon will call your family or friends or we'll talk to them in the waiting area to give them an update. She did great. To learn more about the OR, you can experience our virtual reality video by clicking on the link on our website. It gives you a bird's eye view of what happened in the operating room as your OR team prepares for your procedure. Hello, my name is Anna Rasharm, a registered nurse specializing in patient recovery after anesthesia. After surgery, you'll be brought into the recovery area. As you wake up, me or another recovery nurse will closely monitor your vital signs and pain level. It's our goal to keep your pain at a comfortable level while maintaining your safety. On average, most patients spend about an hour to an hour and a half in recovery. When you're ready to go home, we'll give you and your designated caregiver your discharge instructions. If you're staying the night with us, you'll be transferred to your private hospital room. You might be forgetful in recovery, so key information will be communicated a few times to you and to any family members or caregivers who are there with you. Tonight, just follow the instructions that the pharmacist gives you. Okay. We hope this video has helped you feel prepared and reassured about your upcoming surgical procedure. If you have any additional questions, don't hesitate to ask any member of our staff or give us a call. Here at the Kaiser Permanente Oakland Medical Center, we're working together to make your surgical experience with us a positive one. We're all looking forward to taking excellent care of you so you can get back to doing the things you enjoy and thrive. Thank you.


practices. I think you should create your own, but what do you think? It's interesting that you asked that question because we do talk about best practices. And not to say that whatever works for a particular company is going to work for another one, but I think it's about facilitating that learning in terms of really seeing what are different organizations doing that is working for them and taking a leaf out of there in our workings. Something may work for us, something may not. But then to be able to discern what works for us and what does not, that's where I think the role of the leader perhaps comes in. But I don't see a harm in really looking at best practices, so to say. It may be a used, very a lot used and abused word, but to my mind I think it works because that's how we learn as well. We have role models, we look up to people, we hear from leaders and what are we doing in that sense? That is my exact concern that if you become a company which is eternally benchmarking others, you will never do anything original in your life because you're only benchmarking and following somebody said you go left, somebody said you go right and so you will either choose left or right. You'll never think of going diagonally. I think that's one of the first problems of benchmarking, but I think that the culture of an organization is pretty much the personality of the organization. So it's really like saying that I can look at the way you are and say, okay, Neha is a person who enjoys the outdoors, who goes checking. I think I want to be like Neha, so I'm going to go outdoors, but if I'm not a person who has ever done stuff outdoors and enjoyed it, just benchmarking you is not going to make me an outdoorsy person. Inasmuch as watching Sachin Tendulkar talk about cricketer, it's not going to make me a cricketer or follow cricket because I don't. But do you think a lot of people do that because while you gave my example, I also know of a lot of people who said, I don't know how you do this. I am just not someone who would ever take that outdoors climb to a mountain. So I think it's to each his own and people would get fascinated by some things. But when


Power systems are essential components of modern society, providing electricity to homes, businesses and industries. Despite the advances made in power system design and operation, they remain vulnerable to unexpected events and power outages. These can cause serious disruption to daily life as well as significant economic losses. This paper reviews recent power system blackouts and cascading events focusing on the United States. It examines the causes of these incidents, analyzes the effects and discusses potential solutions. Additionally, the paper identifies key research areas and provides recommendations for further study. This article was authored by Hassan Hayes Al-Halu, Muhammad Esmail Hammadani-Golshan, Takawira Cuthbert-Engenda and others.