EP 110 | Lisa P. Gwin | Biomechanics

Injury Mechanics & Forensic Science | EP110 | Lisa P. Gwin | July 10, 2025 | 2 PM Eastern

Join us for a fascinating conversation with Lisa P. Gwin — a biomechanical consultant, physician, engineer, and former firefighter. With a background that spans emergency medicine, automotive engineering, and injury biomechanics, Lisa brings a truly unique perspective to forensic investigations.

In this episode, we’ll explore how biomechanics helps answer key questions in injury cases: What caused the injury? Was it consistent with the reported event? How do forces interact with the human body? We’ll also discuss the critical role of expert witnesses in court and Lisa’s reflections as she prepares to retire from an extraordinary career.

Don’t miss this chance to hear from one of the most well-rounded experts in the field of forensic biomechanics.

Originally aired on: July 10, 2025

Transcript

00:00:30:08 - 00:00:39:11
Unknown
Hey there, everyone. Welcome to Forensics Talks. Hope you're all doing well on this Thursday afternoon. And, yeah, we got another one for you today. Today we're going to be talking about biomechanics.

00:00:39:11 - 00:00:41:01
Unknown
So my guest today is,

00:00:41:01 - 00:00:44:12
Unknown
Lisa Gwin and she is a biomechanics expert,

00:00:44:12 - 00:00:49:22
Unknown
early on and she spent six years working with Ford Motor Company as an automotive test and development engineer.

00:00:49:22 - 00:00:55:12
Unknown
But she's also worked eight years as an emergency nurse and another 13 years as a practicing emergency physician.

00:00:55:14 - 00:01:02:27
Unknown
She also has experience as a firefighter, emergency medical technician, and a certified fire investigator, which I think is amazing to have that kind of,

00:01:02:27 - 00:01:06:21
Unknown
variety in your past. And, you know, considering what she's doing now,

00:01:06:21 - 00:01:08:25
Unknown
she's currently in Denver, Colorado,

00:01:08:25 - 00:01:20:12
Unknown
where she maintains her clinical practice by volunteering at a homeless clinic. And she's been retained as a biomechanics expert in over 650 cases throughout the United States since joining Biodynamic Research Corporation.

00:01:20:12 - 00:01:38:23
Unknown
That's BRC in 2012. So let me bring her in here. There she is. Hey, Lisa, how are you? Hey, thanks for having me, I appreciate it. Awesome. Well, thank you so much for being here. I guess before we, begin, I guess I should say a big thank you to Jared Carter, who, put us in touch, so thank you, Jared.

00:01:39:00 - 00:01:55:04
Unknown
Thank you, Doctor Carter. Love you. Yeah. Great guy, great guy. And here's a guest. He was a guest on here, too. So he helped us with, rollovers and all kinds of stuff. And so am I guessing is that it is just work related. Is that where you know him from? Yeah. And, Jared's also a bio mechanic.

00:01:55:04 - 00:02:20:21
Unknown
He's got his PhD, in biomechanics. So. Or biomedical engineering. So please, talk to him about bio as well as reconstruction. He's super smart and great guy. But, yes, we met, through this expert witness business. Amazing. So your background and your CV and, I mean, I've gone through your CV, and that was just a brief bio, but I love the fact that you have this diverse background and you got into all these different areas.

00:02:20:21 - 00:02:21:08
Unknown
So,

00:02:21:08 - 00:02:40:17
Unknown
I'm, I'm, I'm a person of varied interests as well. So it's hard for me to focus. So I'm wondering if you're like one of those ADHD people that's got all these different, you know, things you love to do. And but I love the combination of the background. I just think it's a very it's nice to be so well-rounded in so many different areas and then apply it to, you know, the biomechanics.

00:02:40:17 - 00:03:03:03
Unknown
So can you tell me a little bit about your, like how you got there? And then after I want to ask you about, you know, what would be a more direct approach into the biomechanics field so that for the students in the academics, you know, who who want to approach this particular area. Absolutely. A colleague of mine always used to say, what a long, strange trip that my life has been.

00:03:03:03 - 00:03:24:17
Unknown
And that's a grateful Dead, reference for those of you who are very young. But it has been. But it's been so much fun and and yes, I probably do suffer from a short attention span. I think most er, doctors do, and that's good because then we can just go from patient to patient. So, Anyway.

00:03:24:17 - 00:03:44:09
Unknown
Yeah. So it's been really fun. And, and I still have a list of, like, 100 things I want to go do and degrees I want to get. And my husband says no, but, it's one of the reasons I'm in the process of retiring so I can do all those other cool things that I want to go do.

00:03:44:09 - 00:04:04:23
Unknown
But it has been so fun. Amazing, amazing. And what, like, I know there are some biomechanics people that I've dealt with on to some different cases, but what is what is a typical street like a typical path getting into that area? You asked me that. I forgot to answer it. See what in a short attention span I have.

00:04:04:25 - 00:04:38:00
Unknown
So the really it's not short, but it's a little shorter than mine. You know, it always requires a bunch of education. And so nothing's short. That requires degrees. But, probably the most direct approach would be to know what you want to be when you grow up, when you're 18 and go to college, and go into the biomedical engineering field, specifically, like, for my case, it would be like, injury or impact biomechanics, because there's also like the medical device stuff.

00:04:38:02 - 00:05:05:15
Unknown
But if you know, you want to do specifically what I do, it's impact biomechanics or injury biomechanics, and there's a few schools around the country and certainly around the world that have such degrees, my and my colleagues at BRC, as well as, Doctor Elizabeth Rafael, who also does this work are, is is a little bit weirder because we have degrees in mechanical or electrical or aerospace or nuclear, engineering.

00:05:05:15 - 00:05:35:01
Unknown
But then we went to med school, so we sort of marry, you know, the two. But the quicker approach would be to, you know, get your bachelor's, then get your PhD in, or advanced degree, I should say, because there's biomechanics who have master's degrees, in the impact biomechanics or impact biomechanics realm. Yeah. My, the doctor who delivered my first son was an engineer first, and then she became, you know, a doctor.

00:05:35:01 - 00:05:50:02
Unknown
And I was always fascinated. She was just a brilliant woman. And, you know, I think that, like I said, just that having that kind of range of interests or whatever is really important. So when you were younger, were you were you thinking about going into medicine first or what were you thinking about first? No. Yeah.

00:05:50:03 - 00:06:13:04
Unknown
No. So I come from a family of people who doesn't don't believe in doctors and or medical care. Really? Long story. But so, no, that never even occurred to me. So I'm this sort of masked, weird, geeky, nerdy person. And so I went to, electrical engineering school, back in the day when there were, like, no women doing it.

00:06:13:04 - 00:06:37:26
Unknown
And I know there still aren't too many, but, so just nerd it out, you know? And then I worked at Ford Motor Company for a few years, and then, I actually started, doing firefighting and emergency medical technician, then, on my local small volunteer fire department and I was like, oh my gosh, this medicine stuff is so cool.

00:06:37:28 - 00:06:59:02
Unknown
And, you know, you're really making a difference in people's lives every day. Whereas as an engineer, you make a difference in people's lives, but you don't see it, you know, right there firsthand. And so I was like, this is so cool. And so I completely jumped ship, went to nursing school first. And then worked as an emergency nurse.

00:06:59:02 - 00:07:17:09
Unknown
And about ten minutes into that, I was like, oh, me. And I should have just gone to med school. I'm too bossy to take orders. I want to break the orders. You know? So, so that's my long, strange trip. Yeah, yeah, yeah. And that's interesting too. So I started in electrical engineering as well, and then I switched to aerospace.

00:07:17:09 - 00:07:35:04
Unknown
So it's interesting you were sort of on that path as well. So today, if you I mean, you've obviously testified to trials and things like that when you sort of asked on the stand to explain what it is that you do, and I asked this question sort of in a, in a different way with my last guest, who.

00:07:35:04 - 00:07:55:18
Unknown
And that was what did you think you were going to be doing when you got started versus what what is what is biomechanics? What is this all this analysis and different things that you're doing today, you know, and kind of how did it change from what you thought you were doing versus what you're doing today? Well, honestly, at first I really didn't know what I was going to be doing.

00:07:55:21 - 00:08:29:18
Unknown
Except sort of somehow using my engineering and medicine together. And, you know, helping judges and juries and lawyers understand those two concepts. But I was so burned out on medicine, that I was looking for kind of any job, honestly, because I was working 24 hour shifts and I was 40 something at the time, and I was exhausted, so, and medicine's changing, so patients are becoming stranger by the day.

00:08:29:20 - 00:08:59:00
Unknown
So, I was just ready to get out. But still, I wasn't really sure, but what a fun opportunity it was to be able to use both of my backgrounds or sort of all of my backgrounds, and be able to teach essentially, because that's what expert witnesses aren't, right as teachers. And I've always wanted to teach like that was that's still on my list of go back and get my degree in education and go teach.

00:08:59:02 - 00:09:21:04
Unknown
So turns out, you know, that's what we do. That and Mortal Kombat, sometimes as an expert witness here, knows that, you know, it's it's all about trying to discredit us and make us look stupid or bad or untrustworthy on the stand. You know, it's it's just what we do, but, and it's what the other side is paid to do.

00:09:21:08 - 00:09:43:06
Unknown
So that's their job. But. So I didn't really know. But that's what I'm doing now. And it's it's so much fun. Yeah. When I think about biomed clinics, I mean, I'm thinking about motion, I'm thinking about physics, I'm thinking about kinematics. I think about sports. Like, I think about people that use it for sports or for, you know, performance and athletes.

00:09:43:08 - 00:10:06:02
Unknown
And then, of course, I do think about, obviously, the other side, which is, you know, how somebody gets hurt. So what what are like some of the different branches in biomechanics that are there? Great question. And so I talked a little bit before about so injury or impact biomechanics is, you know, really kind of started in the automotive industry.

00:10:06:02 - 00:10:28:17
Unknown
The people at University of Michigan at weight and at Wayne State and Detroit really kind of started it in concert with the big three. And said, you know, how can we make cars safer? How are people getting hurt? What can we do differently? And so that's really what I do, because that's where lawsuits come. And that's who I work for is lawyers.

00:10:28:17 - 00:10:58:12
Unknown
Right. But but, they're certainly medical device folks. Who are, biomedical engineers or biomechanics. And so they study, you know, how to design a better hip replacement or a better stent for the blood vessels in the heart. And, and then, you know, help design them so that they're not rejected by the body. And, like, all kinds of stuff that actually is not my area.

00:10:58:12 - 00:11:26:11
Unknown
So I'm probably ill equipped to even talk about it. But that's a big piece of biomechanics. And then as you mentioned, you know, gait analysis, what causes people to fall down and trip and how can we make people safer in terms of, you know, elderly folks or folks with disabilities? And how can we keep them safe on busses or on crutches or wheelchairs or walkers and things like that?

00:11:26:11 - 00:11:55:24
Unknown
So those are sort of the big. Defining, separations within the biomechanics world. Yeah. It's interesting because there's there's, of course, how the, there's the human body itself, but then there's these external factors like, you know, you're driving a vehicle or you're it's a forklift or it's, some other piece of equipment that injures you. So, so there's these two sides, so there's sort of the internal and the external sort of forces and equipment that that's being used.

00:11:55:26 - 00:12:19:19
Unknown
So, obviously vehicle accidents is probably the big one, like one of the main ones, but I'm assuming like, you know, slip and fall cases and things like that, like our is like, what about product liability and that sort of thing? Is that is that part of it too? It is. And so at BRC where I work, we do everything and we joke because we've been in business for almost 40 years.

00:12:19:22 - 00:12:41:29
Unknown
And so we kind of joke that, like, if you can think of a way for someone to get hurt that we've probably had that case. And so, yes, lots of slips and falls, lots of car wrecks, that are like low speed stuff or sideswipes that generally don't rise to the level of suing the manufacturer of the vehicle.

00:12:42:06 - 00:13:24:01
Unknown
And then, yes, I have a big practice in automotive product liability. Where there, you know, the person is terribly injured oftentimes and suing, the auto manufacturer or what we call the tier one manufacturer. So somebody who makes a part that sells the part of the airbag, for example, to the car manufacturer, but yeah, also, forklifts, I've done a bunch of work, as my colleagues have with, forklift manufacturers where we've been hired as a product liability case, you know, hired by the forklift manufacturer, regarding an injury that's occurred on a forklift.

00:13:24:03 - 00:13:45:26
Unknown
We've also done stuff like, people who dive into a gymnastics pit and break their neck. And then, you know, we're looking at, like, how big the foam cubes need to be. And how deep the foam cubes have to be to protect people. And one of my colleagues had a case where, stripper. I don't think you have to bleep that out.

00:13:45:26 - 00:14:08:01
Unknown
Got her finger caught in the sort of the top of the pole or the hardware that holds the pole to the ceiling. I shouldn't laugh and sued, I guess the bar or some, I don't know whoever. But like if you can imagine a case where we've had it 20 inch seats, I mean, you, you name it, we've probably done it.

00:14:08:01 - 00:14:32:18
Unknown
So anyway, you can hurt yourself. Yeah. Amazing. Keeps it interesting, I guess, you know, yeah. For sure. So another question I had had and I'm sorry if I'm jumping around here, but for example, the human body. Right. Like, so what are what are some of the weak points of the human body? I mean, obviously, you know, they're what are the most common places where you're going to see injuries happen.

00:14:32:18 - 00:14:56:19
Unknown
And is it just because of the it's because you're in a car and you're seated a certain way. But, you know, just overall, you know, somebody in general, what what is the weak point of the human body? Well, I mean, the most common injuries and slips and falls and car wrecks and forklift injuries, you know, everything is, you know, bruises and bumps that really don't account for much.

00:14:56:21 - 00:15:29:10
Unknown
However, I've always been shocked at how well the human body does, and then other times, in something that seems relatively like a nothing, people are catastrophically injured. The neck is certainly a relatively weak point. And and that's because we have to be able to move our head in so many ways. And the neck is relatively small, compared to this big bobblehead that we have, you know, up here.

00:15:29:12 - 00:16:01:14
Unknown
And so the neck and, and if we injure our necks, it can be very catastrophic. Right? A high cervical, cord spinal cord injury can be life changing or life ending even. So, that's kind of a weak point. You know, certainly in vehicles, sometimes lower extremities can get injured, like in frontal, due to interaction with the pedals, or just the floorboard.

00:16:01:19 - 00:16:26:19
Unknown
But, I don't know that they're weak points necessarily, but, you know, those are relatively common injuries, you know, in your chest. One of the things that I kind of thought, well, if I had the opportunity, designer chests, I probably would have put in a request. There's this ligament that's part of the, fetal circulation.

00:16:26:25 - 00:16:51:14
Unknown
I won't get to here, I promise, but it turns into a ligament once we're born. And develop a little bit. And it's kind of wrapped around the aorta. And during or it is kind of important, you know, like, if it tears, you can die within a few heartbeats. And so this ligament, though, if we're in a big frontal crash, you know, our bodies keep moving.

00:16:51:17 - 00:17:18:08
Unknown
Seatbelt holds us back, airbag holds us back. But inside our chest, our heart keeps going forward. And so it puts this stress on the aorta. And then there's this ligament. And right there we sometimes have aortic injuries. They're not very common. And it has to be a relatively high energy frontal crash typically. But but if I were asked to redesign the human body, I might say let's make that ligament a little bit different.

00:17:18:08 - 00:17:43:27
Unknown
Design. Interesting. What about, like, when we when you talk about injuries, you know, at a trial or something like that, somebody gets hurt or like today? Are the are the thresholds for injury fairly well understood? Is there's still a lot of research in that area. Is it always like a, a debating point? It's not much of a debating point.

00:17:44:00 - 00:18:07:18
Unknown
That back in the 50s and 60s, University of Michigan and Wayne State mostly, as I mentioned before, did a bunch of studies and. Either good or bad. Back then, we were able to do stuff that we're not able to do anymore. And so they would, you know, take cadavers and throw them down elevator shafts and things like that.

00:18:07:18 - 00:18:21:18
Unknown
And we also did some non-human primates and but by we, I didn't but other biomechanical experts and researchers at the time did some non-human primate studies, which.

00:18:21:20 - 00:18:48:03
Unknown
Is not nice. But but I think we have to honor those animals by using the research and making changes that are beneficial for humans. Like don't throw away the research because the methodology was sketchy. And so a lot of those thresholds kind of and they're, and they're not a black and white threshold obviously work below this, you know, acceleration or force.

00:18:48:03 - 00:19:14:05
Unknown
No one can possibly get hurt. And above this threshold or like everyone will be hurt, you know. So they're not really thresholds. But yes, they're pretty well established. And the government uses them in the federal vehicle Motor Safety standards. So it's not so much the that's the argument in these lawsuits. Sometimes people are super fragile.

00:19:14:08 - 00:19:42:25
Unknown
You know, old people obviously are more fragile than young people. And then I say old people with a big grain of salt because I'll be 60 in a month. So that's not old anymore. So but but that's not usually the big fight. You know, it's usually about where, how when did the injury occur. And would especially in my practice, which is mostly product liability, would XYZ design have made a difference?

00:19:42:25 - 00:20:16:04
Unknown
You know, there are still a few things, though, where there's still a lot of argument because there's not been a lot of research. A particular example is dish or diffuse idiopathic skeletal hyper usto say that ten times that, which is still not well understood in terms of exactly what the thresholds are. And again, they're not really thresholds, but so there's a lot of fight, a lot of argument in the legal world about that.

00:20:16:06 - 00:20:39:11
Unknown
Luckily, some of our colleagues are doing some research as we speak. And a great paper is going to be coming out, looking at dish in the thoracic spine and injury potential. So there's a few still out there that there's some controversy and that's one of them. How do you handle preconditioned. So it could be a young person, but maybe they were injured before they had something else.

00:20:39:11 - 00:21:06:12
Unknown
And you know, do you have to go into their medical records and try to figure out, hey, what's going on? Maybe they had surgery, something's changed. And then that that is, you know, a sort of a factor in the injury. Absolutely. An excellent point. We at BRC, and other folks who do what we do have, nurses or sometimes other physicians, who do medical records, reviews.

00:21:06:15 - 00:21:29:22
Unknown
And so we dig through and I have a great team of nurses that I could not do my job without. And they dig through the medical records and they look at the preexisting conditions and the post injury stuff that happens. And, and the radiology, like we look at the actual radiology with a radiologist. So that becomes really important too.

00:21:29:22 - 00:21:59:10
Unknown
If there's pre incident radiology and post incident radiology we can compare the two. But you're right I mean I had a case where a guy was like 40 but he had this degenerative condition in his neck and he had a really relatively low speed rear end collision and was fine at the scene and went home and became a partial quadriplegic because of his preexisting condition.

00:21:59:12 - 00:22:17:21
Unknown
And so, yeah, that's super important. Or dish, as I mentioned before, is a preexisting condition that can very much affect injury outcomes. Yeah. You talked about studies before and you have and I'm looking at your CV. You have a number of papers that you've worked on. And, I just want to ask you about some of those, at least the ones.

00:22:17:21 - 00:22:38:02
Unknown
So you have a couple before that, you know, are in some other areas like medicine and stuff before. But I'll, I'll ask you about some of the early ones that had to do with, like there's one here. Force deflection properties for vehicle, vehicular bumper to bumper interactions. And then you went on to do one on it says measurement of tolerable and non injurious levels of back to front whole body acceleration.

00:22:38:02 - 00:23:05:28
Unknown
So can you tell me about some of the that those early research projects and why they were required. Like was it just a gap in the literature. Yeah. Good question. So the first one you talked about, characterization of force deflection properties. Shout out to the, prime, producer and researcher in that paper and Ricky Bernoulli, and, and, and certainly others, that are at BRC.

00:23:06:00 - 00:23:47:21
Unknown
But so BRC developed a, force deflection, methodology, we call it lovingly the bumper crusher. But basically we have a way of measuring, the force deflection properties of relatively low speed. Crashes where we take either, a whole vehicle or just the bumper assembly of another vehicle, and we slowly, you know, not fast, but we very slowly do a force, apply a force on to the bumper structure.

00:23:47:23 - 00:24:16:08
Unknown
And then we can measure the force deflection curve. And ideally we match or exceed the, the damage in a particular vehicle that's involved in a lawsuit, typically. And then we're able to figure out how much force it took to get that damage. Right. And then we can take those forces and then measure, you know, what would be, required to cause the damage?

00:24:16:08 - 00:24:41:17
Unknown
And therefore, how bad is this, really? What was the delta B, for example? And so Mr. Bernoulli and and we, did the study. This wasn't the first study on the bumper crusher. But this was one of the studies that looked at that. The other one you mentioned was the, whole body back to front accelerations, and this one was super fun.

00:24:41:20 - 00:25:08:21
Unknown
And again, shout out to my colleagues, many of whom were authors, but also my colleagues who were willing to participate in this research study participants. What we did is we, picked people up in a kind of a hammock, essentially. To two feet, four feet and six feet above a mattress. Just a store bought typical mattress.

00:25:08:23 - 00:25:32:10
Unknown
Because as kids, we all would jump from the bunk bed and down onto the below our bed. Right? So. Well, this isn't an everyday activity, you know, people can understand what this means. So we basically dropped people on their backs in this hammock on to a mattress, from two, four and six feet. And we measured the acceleration of almost the center of gravity of their head.

00:25:32:10 - 00:25:57:13
Unknown
We have a bike block with a track school accelerometer on it that we each wore, as well as an upper thoracic, accelerometer and a lower lumbar, accelerometer. And so we were able to measure these accelerations in an activity that people have done and can imagine doing without being hurt. Like nobody would really be worried about jumping from the top bunk down to the bottom bunk.

00:25:57:13 - 00:26:26:15
Unknown
Right. And sure enough, we measured some like 30 g accelerations. And of course, no one was hurt, you know, but that sounds like a lot of 30 GS. Oh my gosh. But like, it's a it's a bunk bed, you know, basically. So, we were able to then figure out Delta V's of our bodies falling and landing and then characterize those with low speed rear crashes.

00:26:26:18 - 00:26:51:15
Unknown
That's interesting, though, because, you've got the, you know, these you're checking these, I call them accelerometers or these sensors at different spots. But, you know, just thinking about this, if you have something that hits something and there's sort of an immediate stop, let's say that that's obviously a problem. But I can imagine it's even worse if you get like, this rotation, like an immediate stop, but you get this deceleration of one spot and the head is swinging around.

00:26:51:15 - 00:27:10:08
Unknown
Another point that that could be even more problematic. Now. Yes. And we were careful to make sure that we dropped as a, as a solid, rigid body, essentially. That's why we did sort of a hammock as opposed to just like a sling under our low back because, right, that you could land on the top of your head.

00:27:10:08 - 00:27:35:03
Unknown
And this might be a different story than just a bunk bed kind of a thing. But we've done similar I don't know if there's some deliberate. We've done studies also where people are riding in a vehicle and then of course, we're not in a sling, right? Our head can move independently. When, you know, in the rear crash, the neck extends and then on the rebound or in a frontal crash, then, of course, our neck flexes.

00:27:35:05 - 00:27:55:17
Unknown
And we've done the same sort of sensors with the bike lock in the head, upper thoracic and lower lumbar. And so you're right. I mean, when your head is free to move, you get, you know, different numbers. But what we've also done vehicle to vehicle crashes where nobody got hurt. And we were able to measure those accelerations as well.

00:27:55:20 - 00:28:22:24
Unknown
Okay, that there's another study here I'd like to ask you about. It's the one that says exit time differences between gated and open operator compartments and stand up and controlled lift trucks. And so that one sounds interesting to me. So can you explain what what you did there? Yeah, absolutely. So, BRC was hired by, forklift manufacturer, to study what had been studied several times in the past.

00:28:22:24 - 00:28:56:14
Unknown
But there's still a lot of controversy in the legal world about whether putting a. So so these are stand up lift trucks, not the sit down kind, but the stand up kind. And, there's not like a door, that on the doorway or the compartment opening. And that's required by OSHA because OSHA says if you're in a stand up truck and the truck starts to tip over or go off of a loading dock, we want you to get the heck off.

00:28:56:14 - 00:29:23:02
Unknown
Step off the truck and get away from it. And so they don't want a door there because a door will slow people down. Well, we all know that ocean knows that. But there's still controversy in the legal world. And so, we were hired to, do studies with a dummy, a crash test dummy, and we pushed, lift trucks, stand up, lift trucks off of a loading dock.

00:29:23:04 - 00:29:47:23
Unknown
We also did some where there was a tractor trailer, like. But it was just a flatbed, and they drove away because this is where sometimes there can be a problem where the guy is still loading the truck, but the truck driver doesn't know it and drives away. And the lift truck is in between sort of the loading dock and the flatbed or the trailer, and then can fall in between, or tipping over.

00:29:47:26 - 00:30:13:00
Unknown
So we had a dummy that was instrumented, head, neck, chest, pelvis, accelerometers, as well as rotational velocity in the head, which then we could of course, calculate the rotational accelerations which had not been done before, the rotational stuff. They hadn't done before. And we found that if you stay on the truck, which the dummy is not able to step off.

00:30:13:00 - 00:30:54:08
Unknown
So the dummy stayed on the truck and you know, all cases, but one of our eight nine tests, the dummy would have or, you know, the operator, the dummy, would have had catastrophic or fatal, injuries so that we did. And then we redid, which has been done before. And it's settled science, except in the legal field, that a door slows you down from being able to get off the truck, and that sounds so obvious, but we did, exit time differences, with operators who are, trained forklift operators, lift truck operators.

00:30:54:10 - 00:31:14:27
Unknown
And there was, you know, like a light that comes on and, and then they'd step off and we time the difference between a door and no door. That's interesting. I actually had a case once that was, at an airport, and one of these guys driving the, the lube trucks for the luggage or whatever, and that one was, it did have a door.

00:31:15:03 - 00:31:36:16
Unknown
But what was interesting was, on that one, as I recall, the door had opened and actually was a problem because he went out, but it kind of landed on the door when it was kind of open or whatever. But, you know, the truck's so heavy that it's still kind of got crushed or folded the door. So it's interesting to, to hear what's going on there.

00:31:36:18 - 00:31:55:14
Unknown
So you talk when it's a gated door. It's a locked door. It has like a latch or something that you have to like, you know, kick open or whatever. So. Well. And so, the people who say that doors are a good idea, argue about that. Should it be a latch door? Should it be like a magnet?

00:31:55:14 - 00:32:21:22
Unknown
Should it just, you know, just swing it like, I don't know, what different experts would say, but what we did, was it was basically a magnet, so it was easy to push. But it still slowed us down. And to your point, if a truck is going, if a lift truck is going off of a dock, there comes a point when that door won't open anymore because the dock will be in the way.

00:32:21:26 - 00:32:47:05
Unknown
And if a person steps out, they could be crushed, you know, as the door is slammed shut. So that's another really important part of all of this. Yeah. And I just want to say, in case anybody sort of halfway listening that anyone would do that. But if you're on a sit down lift truck, not a stand up, and you have your belt on which you always have to have your belt on and you start to go off of a dock, you stay with the truck.

00:32:47:11 - 00:33:04:17
Unknown
So it's very different for stand up trucks and sit down trucks. Yeah. As an FYI, I'm going to bring up a question here from yeah yeah please. People watching here. So this is from April. She's asking how does quasi static tests compare with a dynamic test in terms of the forces. So in general you know what. What's the difference there.

00:33:04:20 - 00:33:30:29
Unknown
Great question. And we're asked this a lot about our bumper crusher, which I wish we had a better word for because it sounds so silly, but but that's what it really is, is a bumper crusher test. So excellent question April. So, the forces are the same. So whether it's a dynamic test or, like I said, over, like, you know, 10s the forces are the same.

00:33:31:01 - 00:33:53:24
Unknown
And so then we can say, look at this much damage. You know, if the, if there's two inches of crush, then it would be the same amount of force causing that damage, whether it's fast or slow. And that's the beauty of this test, is that we can is that we can then say these are the same forces.

00:33:53:27 - 00:34:04:04
Unknown
So great question.

00:34:04:06 - 00:34:23:01
Unknown
Hey, Eugene, you, sorry you muted yourself. I can see that right now. Yeah I got it is I as soon as you said it I go damn I'm muted. So I was going to ask you about the hardware and software and you know, the kinds of things that have been used, the equipment and the tools of the trade, let's say, that have been use over the years.

00:34:23:01 - 00:34:49:26
Unknown
So, in your time, how is that change, like from the very beginning? And what kinds of things are being used today, for research or for testing or for whatever it might be? I'm sorry. So the first part of your question again, though, it just has to do with what kind of like hardware and software are used in the trade, like our used in, in your area for research or for studying or for casework, whatever it might be.

00:34:49:28 - 00:35:18:12
Unknown
Yeah. Right quick. Good question. So for us as biomechanics, just the, you know, injury causation part. So as I said before, most of what I do is product liability work. And so most of what I do are big crashes, or, you know, big injuries, you know, even if it's a forklift injury, it doesn't necessarily have to be a crash as such, like a vehicle to vehicle.

00:35:18:15 - 00:35:56:04
Unknown
And so, you know, really what I use is the medical records, the radiology, if we do, you know, like a vehicle to vehicle crash test, I don't do that. The doctor, Jared Carters of the world do that or, you know, other, reconstructionist, obviously. And those tools may have changed. But as far as what I need, you know, I'll get the the, crash test dummy, the anthropomorphic test device at, you know, their output is, you know, head accelerations, head rotational velocities, chest accelerations, things like that.

00:35:56:09 - 00:36:24:29
Unknown
And that has not changed. Now, what has changed in the dummies over recent ish years is that we're looking at, head injury criteria or Hic, over a 15 millisecond time clip versus 36 milliseconds, which is probably far too annoyingly nerdy and geeky for this forum. But that's kind of changed. But a lot of it really hasn't for me.

00:36:25:02 - 00:36:51:28
Unknown
Now, in terms of the reconstruction, I know a lot really has changed. And then, you know, certain conditions that we're looking at, like dish, you know, that research is about to change and really revolutionize a lot of things. But really, what I do nitty gritty, it really hasn't changed in terms of medical records, understanding the reconstruction and then understanding the kinematics, which is just physics, which hasn't changed since, you know, Isaac Newton.

00:36:51:28 - 00:37:13:15
Unknown
So luckily, being an old dog, I don't have to learn a whole lot of new tricks these days. Are you working a lot with doctors and radiologists and things like that? Do you do you have to communicate with them fairly frequently? You said you have a team of nurses that are helping you, but I imagine on some of the casework you'll have to cooperate with other doctors and radiologists and that sort of thing.

00:37:13:17 - 00:37:41:02
Unknown
Absolutely. We we have at BRC a few radiologists that we use. And so I will almost certainly, every case just about sit down with a radiologist. Most of the time I use, Doctor Cynthia Day in San Antonio. But we have others as well. Doctor Ryan Hernandez, who is also wonderful and lives in Hawaii, of all places.

00:37:41:04 - 00:38:16:03
Unknown
So definitely radiologist. And then in terms of specialists, oftentimes, yes. We'll work with, you know, neurosurgeons, if it's a, spinal injury, or orthopedic surgeons who specialize in, spine, or brain injuries will have neurosurgeons, certainly ortho for any sort of, you know, long bone fractures, broken legs, things like that. Oftentimes neurologists or neuro, psychologists, in terms of the long term sequela of brain injuries and things like that.

00:38:16:03 - 00:38:42:20
Unknown
So, yeah. Absolutely. Ma'am. Are there any concerns I want to kind of move in to cases and to trial and sort of your experiences there, are there any cases in, you know, over your career that have really stood out for you, like something you've learned something or made you see things a certain way, or you did something that was really interesting or, or or any of those that that sort of stand out for you.

00:38:42:23 - 00:39:27:27
Unknown
Yeah. I mean, so often we don't meet the people that we are that are the plaintiffs or the injured parties. But I had this one case and it was, just so tragic. A gentleman had retired from the fire service and then became, the chief of a small, fire department. And so he's, like, just living the dream, like I, you know, I have my pension, I'm retired, I've done all this stuff, and now I'm going to be the chief, and I'm just going to help the young guys come up and and learn the business.

00:39:27:27 - 00:40:04:26
Unknown
And I get goosebumps thinking about it. So bear with me. He's on the side of I-94 outside of Kalamazoo, Michigan, and, there's the traffic is being diverted because all these firetrucks are. And cop cars are lined up on the side of the road. And, a young man is not paying any attention and basically just drives right in to, this chief who is at the back of his fire vehicle, changing out of his turnout gear, boots and coat and, you know, the, turnout pants.

00:40:04:29 - 00:40:32:11
Unknown
And it's basically just slammed into and killed, thrown, you know, a bunch of feet. And is that, And I didn't meet him. But I got to meet his wife and his daughters, and at trial, and I could just see how. I didn't want them to sit in and listen to my testimony, because it was going to be hard for them to hear.

00:40:32:18 - 00:40:53:06
Unknown
Yeah, because I was going to talk about icky stuff, you know, and their loved one. But but they told me afterwards that the first time they really heard what happened, you know, down to the like, this car moved this way and pushed him this way and was when I explained it. And so they felt some kind of closure.

00:40:53:06 - 00:41:25:23
Unknown
There, which made my day. Yeah. Another one to be quick was, a criminal case, and, a woman had a daycare and was criminally charged with, a little girl having broken her leg under her care and, she was sitting in the courtroom and, I was able to help her attorney, you know, help the jury understand what had really happened.

00:41:25:23 - 00:41:47:19
Unknown
And the just because she had a particular kind of fracture did not mean that it was abuse, but it could very well have been an accident. And so her life was changed in that day. And don't we all just want to help somebody change their lives, like on a day to day basis, to help somebody in the moment?

00:41:47:21 - 00:42:03:25
Unknown
You made a very good point in that. And this happened to me once, and it was on a, it was on a homicide case and the I, I in working with the lawyers and stuff, I met the family or whatever, and I was thinking about like the things that I'm going to say and what they're going to hear me say.

00:42:03:25 - 00:42:22:26
Unknown
And I actually beforehand I said, look, I said, I, I, I have, you know, when I'm talking about my work, it's rather mechanical. And, you know, I mean, so it's not that I'm insensitive to, you know, what I have to say? I said, so I apologize upfront if it sounds cold and whatever, but that's not, you know, I mean, it's just the way we have to communicate.

00:42:22:26 - 00:42:38:11
Unknown
And, you know, we're just focusing in on the work. But it's a very good point that, yeah. You're just you're dealing with very bad scenarios sometimes. And, you know, as the expert, it's not that we don't feel anything or we, you know, we know this is serious with the families, but, you know, you sort of have to talk about things in a very scientific manner.

00:42:38:11 - 00:42:57:11
Unknown
So it's not because we're cold, it's just because that's that's the way we communicate with these with these things. It's not about not about an opinion or emotion, but it's about what happened. And, you know, trying to get to the bottom of things. So yeah, I think that's a very good point you made. Yeah. Excellent. So in terms of trial, let's talk about some of your experiences sitting sitting in the stand.

00:42:57:13 - 00:43:18:02
Unknown
And, you know what? What do you typically do to prepare yourself, you know, on the stand or do you bring do you bring props? You bring, like, little bones and the skulls and things like that with you, too? Yeah, sometimes. Or toy cars, you know, or my handy dandy little, body right there, you know?

00:43:18:04 - 00:43:46:07
Unknown
So, yes, oftentimes I will. Yeah. Right. Exactly. Sometimes I'll, almost always I'll have a PowerPoint that my colleagues, who are artists, put together for me and, medical illustrators. So everything is exact and true, but also their artistic, which they can attest I am not. Sometimes I'll send them little stick figures and say, make it like this, but look better.

00:43:46:07 - 00:44:12:17
Unknown
And they they're very polite not to laugh, but so yes, always some kind of props, whether it's PowerPoints or otherwise. But yeah, I mean, what do I do to get ready? You know, so much of it is stealing yourself for being told that you're a liar and a biased jerk who really doesn't know anything, and your mom addresses you funny, right?

00:44:12:19 - 00:44:42:19
Unknown
And so. But but that's the lawyer's job on the other side, right? And so I try not to take it personally. That's just their job. And my clients are doing the same for their experts on the other side, but just, you know, knowing the case called, which when we've got 50 cases floating around in our minds, you know, and I maybe wrote a report that was due today on a whole different case, but I'm on the stand today in a different case.

00:44:42:25 - 00:45:03:02
Unknown
God forbid I should screw them up. Right. So, you know, and working with the lawyers about what's important, what's not important anymore. That was when I wrote my report two years ago. What? We're not allowed to talk about. I mean, sometimes the judges say you cannot talk about this, and so you don't want to accidentally say something.

00:45:03:02 - 00:45:24:22
Unknown
You shouldn't get a mistrial. So, you know, really just being super prepared and and knowing the case because that's what it's all about. Yeah. How do you find. So I guess you find that the visuals, that you have and things it helps with the jury or the judge to understand what it is you're talking about. Because obviously if somebody looks at a radiograph, they're going to be like, I don't know what I'm looking at.

00:45:24:29 - 00:45:54:11
Unknown
Right. So yeah. Well the the cool part is as an er doctor, you know I had to explain crazy hard topics in two seconds sometimes, you know. Yeah, I took care of a guy once. I worked in Wyoming, and this guy was mauled by a grizzly bear like my training did not include that. Right. But luckily, trauma is trauma, whatever it is.

00:45:54:14 - 00:46:16:12
Unknown
And so I had to turn to him and say, here's what we're going to be doing in the next two seconds, and it's going to include knocking you out and putting a two down your throat. And, and, you know, flying you to somewhere else and then telling his wife what had happened and, it turns out his wife worked, at Shock Trauma hospital in Baltimore, which, like, invented trauma.

00:46:16:12 - 00:46:38:05
Unknown
So she was an easy sell. But yeah, but but I mean, as a doc, I had to explain stuff all the time. And then as a nurse before that, I had to explain stuff that the doctor said that didn't make any sense to patients. And so luckily, I think I have a knack for coming to different levels depending on who my audience is.

00:46:38:07 - 00:47:03:29
Unknown
And so I hope you know that, that I do a good job in explaining relatively hard concepts in an easy way, although that's one of the things I'm always thinking about is what is the jury going to think I'm really saying? And how can I explain this difference or this injury or these physics? To people in a jury that don't have a degree in electrical engineering?

00:47:04:02 - 00:47:20:17
Unknown
Yeah, I think that's right. Absolutely. We got a couple of questions here. Do you want to bring a couple on? And we'll just do the rapid fire here of questions. So this is your note. Hey, you know, is bone density taken to consideration, which usually decreases with age? Besides the obvious head and spine being the most critical.

00:47:20:20 - 00:47:51:18
Unknown
Fabulous question. And so as our population's age, across the world, because medicine's better and people are living longer, things like bone density become really important. And there's a ton of literature out there about how bone density affects injury outcomes. And, you know, specifically like rib fractures, because obviously in elderly people, a few rib fractures can kill them.

00:47:51:20 - 00:48:14:19
Unknown
Whereas if I, I shouldn't say I if some of you young folks had rib fractures, it would suck, but you wouldn't die, right? And so, yes, this is really important. And let me try to pull in the other question that was asked, which is if the plaintiff has a different set of medical issues than maybe the person.

00:48:14:21 - 00:48:40:06
Unknown
Yes. Thank you. That's in the test. How do I account for that? And so, these wrap into each other because I might sit in a vehicle and be subjected to a rear crash with the accelerometers on me, right? Or in my mouth. And so because I wasn't hurt doesn't necessarily mean that someone else couldn't be hurt.

00:48:40:08 - 00:49:05:09
Unknown
So the way we look at that. So if it's a person with osteoporosis, if it's a person who has a prior neck fusion, which puts them at increased risk for an injury above or below the fusion, or a person with a degenerative condition in their neck or back that can cause them to have a lower threshold, for a very catastrophic injury.

00:49:05:11 - 00:49:35:08
Unknown
So how do I make that leap? And that's very important. And that's one of the things that's so important in the legal field is. Well, doctor Gwen, you weren't her. Therefore no one could possibly be hurt. I would never say those words because we all know that everybody's a little bit different. However, if if we can correlate those acceleration motions that were measured on my body to activities of daily living.

00:49:35:11 - 00:50:17:11
Unknown
So there's a lot of research up out there about how much acceleration is in your head, your back, your neck. If we do jumping jacks or if we ride the subway and are jostled around or, we horseback ride, you know, we have a lot of data. And so if a plaintiff is a former horseback rider or current even, but rode a bunch of horses, and in this crash test that I did as part of their litigation, we measured two GS of acceleration in my head, let's say I know that two GS is like sweeping the floor or pushing open a door.

00:50:17:11 - 00:50:53:04
Unknown
Maybe, you know, at the store with your arm or being jostled in a crowd. And I also know that horseback riding can impart like up to 15 GS or something in the head. Well, if Miss Jones was subjected to 15 GS in her head and wasn't injured previous before this, whatever the incident is, that's part of the litigation, then it's pretty unrealistic to think that two GS in this vehicle crash, if that's what we're talking about, would have caused her this catastrophic injury.

00:50:53:06 - 00:51:13:16
Unknown
And so that's how we're able to correlate because the two GS is the two GS. So I'm measuring I'm just a test device in my crash test. Right. And so it's two GS. So it would have been two GS for Mrs. Jones as well. And therefore the chances of her being hurt are like nil. Right. Right. Okay.

00:51:13:16 - 00:51:37:23
Unknown
That makes sense. Let me let me bring up another one. Here is April again. Doesn't injury related. Your time is important. The accelerations experience. Yes. And that's a great point. There's a lot of, forklift literature that that does this jerk stuff. Which is so great question. Yes. And so what we look at, though is accelerations.

00:51:37:25 - 00:52:03:25
Unknown
And then we can compare. So let me back up. So the force deflection, the bumper crusher. We're not able to do a bumper crusher or a force deflection test and say the acceleration of the head of Miss Jones in this litigation was X. But what we can do then is use that reconstruction, use that force to do a reconstruction with the force.

00:52:03:25 - 00:52:36:08
Unknown
What would the Delta V be on the vehicle then? We use the literature that looks at vehicle to vehicle crashes at a particular Delta V and real world crash data out there in the federal system or mass systems databases and say it this delta v, the risk of an injury to a particular part of the body is whatever it is 30%, 50%, 1%, 0.0002%.

00:52:36:10 - 00:53:05:02
Unknown
And so that's how we're able to take those accelerations and do multiple steps in between to try to figure out the person's acceleration or the body part acceleration, and then the risk of injury. Let me ask you about some of the areas where if if you could, you know, if we suddenly rewind the clock on you and it's 15 years ago, what what are you, you know, your career, in your career, but not 15 years ago, like today.

00:53:05:02 - 00:53:36:05
Unknown
What are some of the open areas or the areas that really need focused study, research that have to really be looked at seriously right now? What what what areas would you advise somebody to start looking at? Because it's going to be important to your discipline. One of the big the hot topics is women, and injury potential in women because the crash test dummies or at DS our kids, males midsize male and large male.

00:53:36:05 - 00:54:02:15
Unknown
And then there's the fifth percentile male female. And so what about regular size women who are fifth percentile, right. And how are we looking at the difference between women and men? So if you look at the male dummy in the female dummy, the only big difference is size. And it's the same sensor, you know, in there in the, in the test device itself.

00:54:02:15 - 00:54:35:29
Unknown
Sensors, plural. And so actually, one of my colleagues, Doctor Richard Watson, is in the process of doing some research on that, using the federal databases of cysts and nass. And that's a big topic these days. I think, you know, I mean, so much of the vehicles are changing all the time, right? Because the automotive manufacturers are trying to make everything safer.

00:54:35:29 - 00:55:08:03
Unknown
That's obviously everyone's goal. And knits, the federal, our US federal government has mandated, you know, a lot of decreases in injuries and, you know, certain airbag. And they mandate a lot of designs and things like automatic driving assistance systems, like automatic emergency braking and things like that. So I think a lot of future research will come or that's necessary is regarding those systems.

00:55:08:05 - 00:55:31:11
Unknown
Do they change injury outcomes? Are they also feasible because it's great to have some, you know, mush or like a bubble that just appears around your vehicle when it's about to get in a crash. But is that feasible? You know? Right. So I think that's going to be a lot of it is injuries and, and of course, I'm focused on the automotive industry.

00:55:31:11 - 00:56:00:13
Unknown
And, you know, the product liability type cases. So but I think that's going to be a lot of research coming up. But do you think that there are some injuries like let's say, for example, where a man is more prone to an injury than a woman or vice versa? Maybe, you know, bone density, that of bringing up, the question from earlier, bone density is typically lower in elderly females and elderly males.

00:56:00:16 - 00:56:30:18
Unknown
Again, this is not a blanket statement, but generally and some studies have looked at that, you know, that there's other things too, where obese folks which could be male or female, but, you know, obese folks have a different potential for injury in some areas. You know, so, yeah, I mean, there might be differences. We're going to find out, actually, because as I said, Doctor Watson is doing that research as we speak.

00:56:30:20 - 00:56:50:15
Unknown
I'm going to bring up the, BRC online, page here, and I guess you're on it there. But this is just in case people want to go and find out some things, but, do you do any, like, were you doing any training? Like, if you like, do you want to educate people on this? Or it may be for lawyers or for people that are doing litigation, like you just does BRC do that sort of thing or do you?

00:56:50:18 - 00:57:24:27
Unknown
Yeah. You know, generally, as a marketing feature, when we have newer folks, they'll go to legal conferences and do teaching of lawyers. Like, what can we offer you, you know, and some injury outcome, research regarding, you know, airbags and things like that. We also have and I don't know if we still do, but we certainly did, teach, by, an injury biomechanics course.

00:57:24:29 - 00:57:49:27
Unknown
At the undergrad and graduate level at the University of Texas in San Antonio. Certainly people can reach out and invite us, you know, to come and talk and, and talk about this stuff, either to, you know, lawyers or students. I've been invited to talk at, the University of Colorado for, you know, undergrad students that might be thinking about biomedical engineering.

00:57:49:27 - 00:58:06:27
Unknown
You know, what are some career paths and things like that. So we're available for sure. You talked about retirement. So we sort of started there when we first will we first spoke. You're like, well, you know, I'm retiring. So I don't know if I'm you'll be able to speak. And I know that's you're the best person to speak because you got all this experience, which is fantastic.

00:58:06:27 - 00:58:30:09
Unknown
So but what is your what is your next move? I mean, you're going to retire, but you don't strike me as a, as a person that that stays still all that much. So I feel like you're going to be doing maybe some other career or something. I'm not sure. Yeah. And TBD, you know, I, I'm determining that every day as I go, but, I'm interested in a bunch of volunteer things.

00:58:30:09 - 00:59:00:10
Unknown
And so when I was super busy, I would get these volunteer opportunities and I feel like I can't take a whole week off and go, you know, Scoop Bear poop or help build tiger habitats. And, but now I can. And so my husband and I, in June, May, June, I don't remember now, went to an animal sanctuary and, you know, helped rebuild, a habitat for a new lion that they have.

00:59:00:10 - 00:59:30:06
Unknown
And, we also volunteer for a group called Historic Corps, and they work with, government agencies like the Forest Service and things like that to help, rebuild and maintain historic structures. So, like a fire lookout tower and things and so getting to use my power tool and construction, not expertise. I wouldn't even say knowledge interest.

00:59:30:09 - 00:59:46:18
Unknown
You know, so things like that, and, you know, just being able to do the stuff that I've always wanted to do but didn't have time. That sounds amazing. Well, look, I would just want to say thank you so much for your time and for talking to me and, talking to the folks, answering questions, and, yeah, it's great to have you.

00:59:46:21 - 01:00:02:07
Unknown
I want to wish you all the best in the retirement and yeah, hopefully, I don't know, people say who people when people retire usually the the the or the, the feedback I get is I don't know how I did it before. I'm, I'm like busier now than I was ever before. So yeah, you might find yourself in that situation.

01:00:02:07 - 01:00:19:23
Unknown
You never know. Absolutely. Thank you for the comments. I see the, backyard chickens. My neighbors have chickens, and so I get my chicken fix that way. But thank you for the really nice comments and questions, and thank you for having me as a guest. It's been a delight. All right. Great. Hey, hang back for just a second and I'll come back and chat with you.

01:00:19:24 - 01:00:20:24
Unknown
Thanks.

01:00:20:24 - 01:00:22:29
Unknown
Okay, folks, that does it for this one,

01:00:22:29 - 01:00:30:18
Unknown
topic that we hadn't done before, so I'm really glad we could do that one. And, I think we'll cover that one again. There's other areas in the whole biomarker annex,

01:00:30:18 - 01:00:34:25
Unknown
discipline that I think that could be covered even better. So, thank you for all the comments.

01:00:34:25 - 01:00:41:23
Unknown
Thanks for everyone. And watching from like different places. So have a happy Thursday and we'll see you all very soon. Take care. Bye bye.