In this episode, Physiotherapist and Sports Injury Researcher, Kerry Peek, talks about sports injury research and the neck.

Today, Kerry talks about her research into sports injuries, developing training programs, and evaluating feasibility and adherence to programs. How can greater neck strength assist in reducing head and neck injuries?

Hear about measuring neck strength, defining “normal” neck strength, and get Kerry’s advice to her younger self, all on today’s episode of The Healthy, Wealthy & Smart Podcast.


Key Takeaways

  • “You wouldn’t send an athlete out without doing knee exercises, and yet we do it quite regularly with the neck.”
  • “We need to do some isometric exercise but with ballistic intent.”
  • “I don’t think isolated neck exercises is going to give you the best bang for your buck.”
  • “The best exercise is the one they’re going to do.”
  • “We need to make sure that the research in this space is high-quality research.”
  • “We need to be more critical in the way that we apply research in neck strengthening.”
  • “If you’re really good at designing exercise programs, get creative.”


More about Kerry Peek

Headshot of Dr. Kerry PeekDr Kerry Peek (PhD) is a physiotherapist, behavioural scientist, strength-and-conditioning coach, and sports injury researcher with the University of Sydney. She has over 20 years of clinical experience in both Australia and the UK working with many athletes across a range of sports, age groups, and playing levels, including elite athletes in football (soccer), rugby, motor racing, American football, and athletics.

Her current research is focussed on mitigating sports related head and neck injuries and has just completed a project on neck strengthening and heading funded by a FIFA Research Scholarship. Kerry has presented to the UEFA medical committee and assisted in drafting UEFA’s heading guidelines.

Kerry is the Chair of the New South Wales State Council for Sports Medicine Australia.


Suggested Keywords

Healthy, Wealthy, Smart, Healthcare, Physiotherapy, Research, Injury Prevention, Neck Strength, Exercise, Training,


Recommended Reading

  1. The Effect of the FIFA 11 + with Added Neck Exercises on Maximal Isometric Neck Strength and Peak Head Impact Magnitude During Heading: A Pilot Study
  2. Injury Reduction Programs for Reducing the Incidence of Sport-Related Head and Neck Injuries Including Concussion: A Systematic Review
  3. Purposeful Heading in Youth Soccer: Time to Use Our Heads
  4. Higher neck strength is associated with lower head acceleration during purposeful heading in soccer: A systematic review
  5. The effect of ball characteristics on head acceleration during purposeful heading in male and female
  6. Heading incidence in boys’ football over three seasons
  7. The incidence and characteristics of purposeful heading in male and female youth football (soccer) within Australia
  8. Neck strength and concussion prevalence in football and rugby athletes 


To learn more, follow Kerry at:

Website:          Kerry Peek

Twitter:            @peek_kerry

ResearchGate: Kerry Peek


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Read The Full Transcript Here:

Hey, Carrie, welcome to the podcast. I’m so happy to have you on.



Thank you so much for inviting me.



And just so people get our connection, I was in Monaco for the IOC conference, and I went to one of the platform presentations, and you were discussing your research, and I found it to be fascinating. So you do a lot of work with the neck and head and I just absolutely loved it. I loved your presentation. I learned so much about it. And then as I dug deeper into you, I realized that you and my friend Evangelos Pappas, there was a connection there. So I texted Evangelos. And I said, you know, Carrie peak? He said, Yeah, I’m like, Oh, cool. Could you like, tell her that? You know, I really liked her presentation, because I was like, and, and I’m, I’m sitting right behind her. I don’t know if he texted you that you’re like that. It was like a psycho or something. I’m like, I’m sitting behind her.



He did text me that and it was just really funny to have this funny conversation between Australia and we’re in Monaco, and you’re American. And yeah, saying, oh, Karen sitting behind you make sure that you introduce yourself. Yeah. After the presentations are finished.



Yeah, that was funny. But I loved your presentation. So now I can’t wait to talk about your research on this episode. So I’ll just kind of throw it over to you to talk about kind of the body of your research and why you chose the topic that you did.



Yes, I am. I’m a physiotherapist. And now a sports injury researcher and I started in the early 2000s, working with Don gatherer, who is the former England rugby physio, and was the Chief Medical Officer The is the Chief Medical Officer. Sorry, I’ll start that again. So yeah, so I started as a physiotherapist, I graduated in the late 90s. I graduated in the UK and I worked with Don Gajraj, who was a real mentor to me, and he was the former England rugby physio and also went to two Olympic Games. And he’d really developed a practice which specialized in neck rehabilitation. And this was an area that I don’t really remember studying an awful lot at university, like we did manual therapy. And really, as soon as you got patients pain free, they were free to go like I don’t remember really doing a lot of neck exercises. And so we had lots of players that played rugby, we had OpSite athletes, and we had Formula One drivers coming into the clinic, who had had a history of head or neck injuries. So concussion, which wasn’t really talked about much in the 90s. But looking back, a lot of them work and cast. And we started doing a lot of rehabilitation, and I really am an exercise based physiotherapist. I really like doing manual therapy. And so it was just fascinating to to really come from that perspective to see, okay, what’s the mechanism of injury? And how can we replicate this, you know, doing various exercises are really sports specific. I then moved to Australia and had children and got distracted bit by doing other things for a few years. And it wasn’t until my son as an eight year old was heading a football, that I thought, actually, we should probably be looking at neck exercises in this cohort, considering they’re using their head to you know, deliberately redirect the ball. And that really sort of got me down this, I suppose research rabbit hole, because at that time I was doing my PhD. And since then I’ve moved to the University of Sydney. And so really what my research is focused on now is how we can mitigate sports related head and neck injuries.



And so of course, you know, my next question is, what is the rationale for why training the muscles around the neck can play a role in reducing sports related head and neck injuries? Because, boy, it seems like some low hanging fruit right doesn’t cost a lot of money, easy to implement. So what’s the rationale there?



So I mean, first of all, I want to say that I don’t think that next month is going to solve every head and neck injury. You know, I think it’s part of a multifactorial approach where we will look at more changes and look at, you know, whether that’s body checking or collision. But it when we’re talking specifically about neck exercises, I mean, the notion that greater neck strength can reduce head acceleration, particularly during heading or during collision sports is that stronger, stiffer, next, increase the coupling of the head to the body, and then help to stabilize the head on contact. So whether that’s body contact or head contact, and so really, we’re looking at the stiffness, which is the ability to resist defamation, and then the strength which is then you know, being able to increase neck stiffness. And so it is really that coupling between the head, neck and torso.



And how do you explain this to a patient that you’re giving these exercises As to increase neck stiffness, because I know a lot of people might think well wait a second, I don’t want my neck to be stiff. So how do you can? And I love that you define that? Would you mind repeating it? Because I think it’s really important. And how do you explain that to a patient.



So I tend to explain to my patient by using sort of the picture of a bubble head, so I do call them bobble heads. So you’ve got this figure, and then this head that moves really freely. And you think if you, if you nudge the, the head, it wobbles, you know, quite a lot. And so that’s a lot of head acceleration, even if you touch the body, the head will also move. And so if you think if you are being tackled in sport, or you’re heading the ball, then there’s a lot of head acceleration there. And we use sort of head acceleration, we measure it, you know, with inertial measurement units, thinking that you know, this, if the head is moving a lot, the brain is moving a lot. And so if you can reduce the amount of head acceleration by increasing the strength and the stiffness between that bubble head and that fixed body, then that’s a way to hopefully reduce some of the movement of the brain within the skull.



And that makes a lot of sense. And I think that is a great way to say that your patient, because they’ll better understand what you mean by neck stiffness. Because I can just see, like, eyes getting wide, like, I don’t want a stiff neck. But you’re like, Well, when I wait a second, that’s not what we’re saying, We want you to be able to the neck is still mobile, but we want you to be able to accept those forces when they’re placed upon you. Right?



Exactly right. And, you know, we know that head injuries and things are getting more prevalent in, in sport, and whether that’s because of increased reporting, or whether it’s just because the athletes are getting fitter, faster, stronger. And so some of the hits that you see in American football, and in rugby league and rugby union, I mean, they’re horrendous. And, you know, if you’ve got this head that is really not well connected to the body, and you’re being hit by a, you know, 100 kilo athlete, then that’s such a vulnerable component. And I think that the neck, really working in this space, it’s the last area of the body that we routinely exercise, you know, you would never send an athlete out, whether they’re that’s a prevention or whether they’re post injury, without doing the exercises, you know, you wouldn’t have an ACL and say, right, there’s no pain there, off you go. And yet we do it quite regularly with the neck.



Yes, very much. So. And now when we’re talking about strengthening the neck, how do you measure this, the strength of the neck.



So there are lots of ways that you can measure the strength of the neck. And a lot of these different methods have been shown to have good reliability. My issue is whether they’re valid, and they’re valid within particular sports cohorts. So when you’re looking at assessing neck strength, I mean, generally, when you’re looking at any assessment of muscle strength, there’s reasons why you do this, you might be using it as an outcome measure. But generally, you’re doing it to inform the load that you will input you you will apply when you’re then exercising. So when you measure neck strength, it has to have some carryover to the position that the athlete is going to be in for their sport. And it also has to have some carryover to what you’re trying to resist. So in with the neck, for example, you’re trying to resist lots of head accelerations. So generally, you need to assess the neck using isometric or maximal isometric contractions, because you want to resist movements. Most sports are upright, you know, they’re running, jumping, walking, running, and, and so you need to be upright when you test them. If that’s how you’re also going to exercise them. Now there may be differences. So if you’re a rugby forward, you’re going to be in a scrum position. So there may be reasons why you want to replicate a scrum position to test an athlete. But some measurements of neck strength are done in a supine and prone position. And these can often give you very different neck strength profiles, to when you actually assess somebody’s upright. And there’s problems if you are assessing someone in supine or prone, but you want to exercise them upright, because because you just don’t know what the actual maximal strength score is in that sport specific position. So the way that I mentioned extreme is that I get them fixed in a seated position because I can standardize that position much better. And I use a break technique. So this is really looking at eccentric loading in an isometric position until you can break the contraction, I guess, of the neck. And this is shown in lots of different areas of the body that a brake technique will yield much higher scores than a mate technique. And so again, if you’re using the brake technique, particularly because you’re generally trying to keep the head and neck still when there’s contact placed on the head or body, and then that is sort of like an eccentric load. So this will give us our maximal score, for which Has the flexes extensors left or right side flexes. And then this gives us a much better maximal result that we can use for percentage of one rep max when we’re thinking about load.



And are you using a handheld? dynamometer? for that?



Yes, I probably should have said that first. Yeah, but I am using a handheld dynamometer with a load cell in series that’s placed on the head with a with a head harness. And so yes, you do incrementally load that.



Yeah. Nice. And now, how, how do we know what normal is? Like? What’s a normal strength profile for NEC? And and then how do we know what’s normal for a position within a sport?



And that’s a great question. Because when you when you look at the literature that’s out there, the first thing I always do is I look at what was the method to assess neck strength. And if it is in a lying position, then I take the results slightly with a pinch of salt, because they too tend to give you a different neck strength profile. So there are a lot of studies particularly in rugby that have been tested using the same method that I that I use. And this was first developed by by Don gatherer. So it’s not any great surprise that I use that because we used in clinic for a very long time and tested hundreds of athletes. But now having moved into that research base and had a look at all the different ways that you can test neck strap, it’s still my preferred method. And so we’ve tested rugby athletes, we’ve tested football players. And what we’re generally finding, and this is sort of consistent with the literature. And what we expect a neck strength profile to look like is that the extensors should be the strongest. So if you look at a result, and the extensors are not the strongest, is it related to the testing technique or the position that they’re tested in? Or is there a problem there, so it isn’t an injured population, that might give you something that’s a bit different. So extensors should be strongest flexors are generally the weakest. And side flexors will sit somewhere in the middle there, depending on the population. So in rugby and American football, you often do want to have the side flexes to be stronger, and a lot stronger than the flexes. So they tend to have a very wide sort of neck radar if you were to plot this on a graph. Whereas if you have football players, for example, because of the conditioning from hitting a ball, they may actually have quite strong flexes. So I always have a look and plot the results on a radar. And then I also calculate the flexure to extensor ratio to see what that looks like. And so in the literature, normal is often considered around point six of a flexor extensor ratio, but I have seen it as low as point five as high as point seven. But I always think if in a sporting population, if it’s below point six to me, that’s that’s honestly a red flag, but it’s certainly a yellow flag.



It’s problematic, or can lead to can lead to more problems. Yes. And where can people if they’re wondering like, hey, where can they find the method that you use to strengthen? Is there a paper? Is there something you can point to because we can sort of put it in the show notes?



Yeah, so I do detail the the method for assessing neck strength and a paper that we published earlier this year in sports medicine. So we looked at the neck strength of football players, adolescent football players from 12 to 17. And then we implemented an X strengthening exercise program and to see whether by strengthening the neck this actually had an impact on reducing head acceleration during heading, and we found that it did so that the neck strengthening method is is detailed in that paper.



Perfect. So we’ll have that paper, we’ll put it in the show notes a link to it so that people can read it at their leisure. Now, we talked about why you’re looking at it, how you’re evaluating it, what does a training program look like?



So that’s, that’s really interesting as well, because I think, because there’s not a lot of published literature on neck strengthening, I think you tend to find that you have different camps of people, some that are very pro neck strengthening, and that that certainly is myself. And, you know, a bit like you were saying earlier is that it’s low hanging fruit, you know, why wouldn’t we try and strengthen it because the potential gain is huge, and it wouldn’t not strengthen any other area of the body. So I kind of think what, you know, why wouldn’t you do it? But on the back of that, we also have to think what’s the best way to strengthen the neck and I think some people are quite negative towards neck strengthening, because some of the papers that have been published, the exercises that they use are sort of self resisted exercises where they’re pushing against their forehead and holding that and doing isometric holds. And a number of studies have shown that this doesn’t really have an impact, it may not even impact in which increasing strength and it may not have an impact in reducing injury risk as well. And that makes sense. You know, I don’t implement those exercises because When you’re talking about reducing something like concussion or heading in football, those hits happen in fractions of seconds. So we don’t need to have high insurance of the neck or just isometric control over a long hold, what we need to be able to do is fire those muscles really, really quickly. And so we’ve been playing with some neuromuscular exercises. So it isn’t our paper that was published in sports medicine, but I’ll try and describe it, but you’re kind of in a setup position, but you’re rolling backwards and forwards, and you’re trying to stop your head from hitting the ground. And so the idea from that is really to try and contract the neck flexors really quickly if the heads in neutral, and then we turn the head to the side and the other side, and we do the same exercises. But the idea is that you’ve got that anti gravity strengthening, but you’ve also got, you know, you’re trying to stress the muscles to fire really quickly. And that’s what they have to do. So most of the the literature that is talking about neck strengthening is sort of indicating that we need to do some sort of isometric exercise, but with ballistic intent, and that’s the bit that is often missing, for most of the neck exercises in the literature.



Yeah, and that’s the exercise you described in Monaco, sort of, for people, if you’ve ever taken Pilates, it’s rolling, kind of like rolling like a ball is kind of what that’s kind of, you know, that’s, that’s at least what I got from it. And I remember I got back to my room, and I was like, we’re gonna try and see what happens here. And it is it not as easy as it sounds.



No, and, and it does, it does work the net quite hard. And you can see it, you can see the net contractions in somebody else that’s doing it. But the way that we sort of played with this exercise, and I will just credit to bursting, but also, we meet on a regular basis. And we talk about neck exercises. And he’s also widely published in the neck strengthening arena, and was part of this paper as well. But what we were trying to do was come up with an exercise that use no equipment that didn’t take long. So these exercises take 90 seconds. And that could be added to an existing neuromuscular program. So in this case, we added it to the part two of the FIFA 11 plus. And this is really important because I actually don’t think isolated neck exercises is probably going to give you the best bang for buck either. I think we need to integrate it into, you know, other strength and conditioning programs. And again, this is sometimes where you see in the literature that they’re just adding neck neck exercises without thinking about, or what is that neuromuscular control to the trunk as well. And how are we stimulating that?



Yeah, that makes so much sense to not just do things in isolation. I mean, gosh, especially when you’re talking about athletes who rare? There’s not many athletes that do things in isolation?



No, no. And and I think that that’s just really important to get that adherence as well. Because if they think it’s an add on program, and it’s going to take ages and 10 minutes to an athlete is actually quite a long time when they’re doing so many other areas of the body, that if we could integrate it into existing programs, or integrating into multi joint movements, then it makes sense to them. And it and it’s, it’s it’s integrated. It’s not an add on.



Right? Because of course, as we all know, as physio therapist, one of the hardest things through a rehab process is the patient that doing the rehab. Right, so the best exercise is the one they’re going to do. So if you explain it well. And you integrate it, you’re more likely to have that patient do the exercise. Have you found that? Have you found difficulty patients adhering to the program?



So, so we didn’t, we did, we did look at the evaluation of feasibility. So my PhD is actually on adherence to exercise. So it was something that was really at the forefront of my mind when setting any exercise intervention, that we need to have some sort of process to evaluate it and see whether the, you know, the players and the coaches found it feasible, and did it take too long could they see the benefits of it, and it’s generally scored really, really highly. And I think that is the fact that we tried to just minimize the time that it took that it was complex. So you know, the youngest athletes were sort of 12 years of age, and you know, they all understood what they needed to do, but also to make it you know, applicable to their sport. I think that’s really important.



And what are your thoughts on different kinds of strengthening you know, we see things on YouTube people will see things on YouTube and I don’t mean to go down a rabbit hole on that, but you know, tying weights around their head bands around their head doing things with bands and weights with movement of the neck. What are your thoughts on that?



So there’s certainly some crazy stuff on on YouTube or Tik Tok and I think that’s not necessarily specific to the neck. I just think that again, what you’ve got to try and do and, you know, I think exercise therapists, whether that’s physios or exercise physiologist that do exercise really well, they understand the sport and they understand the mechanism of injury. And so if you’re going to add a weight to your neck, you’ve got to think, Okay, well, how am I adding the weight? And how is it replicating, you know, the risk of injury, or what I need to do within my sport. And so if you’re in a crouch position, which I’ve seen in lots of videos, where they’ve got a head harness, touch the neck, and then there’s really, really heavy weight at the end. And I kind of think, why you’re doing that, what’s that for? And maybe in the scram, maybe that’s applicable, but you know, I can think of very few reasons why you would need to do that. And when they hang weights off the top of their heads, you know, you think of that, you know, that axial loading that they’re doing. Again, why would you want to do that?



Yeah, I don’t know. That’s why I asked, and so we got an answer. I don’t know, I really do not know why you’d want to do that. But now now listening to you talk about your research, it just makes so much more sense to integrate it in a neuromuscular based exercise, you know, integrating it with other muscles within the body and making sure that it makes sense for the position and the sport of the person. Yeah, absolutely.



And I think this is about knowing, knowing your patients, knowing your athletes, and, and if you apply that sort of methodology for any exercise, you know, whenever you see someone, so I’ve been invited to do some work with the RW F here, so the Air Force, and I don’t know a lot about PILOTs, but you just go in here, talk to the pilots, and you say, okay, so what do you do? And you know, when does your neck hurt? And? And how long are you in that sustained position? And how much G force are you being exposed to when you’re in a fighter jet? And you just kind of start to understand, you know, what, what’s happening to this person? And how is that potentially, you know, making them at risk of injury? And then how do we need to train those muscles in a way that stimulates, you know, what they’re exposed to as part of their job or part of their sport? I mean, you do that with every other joint of the body? You know, I think we routinely do that. But we just need to do it at the neck as well.



Yeah, and great advice. And now is there anything as you know, throughout our conversation today that we didn’t touch upon, about your research, maybe about your PhD work that you think would be audience would really love to hear more about?



Um, I think that it’s important. I think it’s important than I think I sort of said this a bit earlier on that, we really need to make sure that the research in this space is really high quality research, and that we understand, you know, the mechanism of injury, particularly things like concussion, that we don’t think that neck strength is going to solve everything. But you know, when we’re reading papers, it’s understanding, you know, what method did they use, you know, are the results actually believable, or didn’t the way that they measured neck strength have given you such an unusual profile that actually shouldn’t read any further in the paper, or it’s just not applicable to your athletes, for example. And so I think that we need to be much more critical in the way that we apply research in neck strengthening. And I think that, although I’m very passionate about next trend thing as an intervention, you know, I don’t think we should overplay what we can potentially do in this space, either. It’s just part of our toolbox, but it’s not going to be everything.



Yeah, there. It’s not the panacea for all ills having to do with head and neck injuries.



That’s right. And I think that if you don’t understand about how to integrate a neck strengthening program, I mean, I’m very happy for people to reach out to me, but, you know, talk to people and, you know, as I say, critically appraise what’s going on. And I think, you know, if you’re really good at designing exercise programs, get creative, you know, have a little bit of a play of what you’re trying to do. And I think that’s often how we get really innovative in the way that we approach exercise programming as well.



Yeah, and it also sounds to me like there’s not a one size fits all. Approach, exercise or program. No,



I mean, I think there’s things you don’t do. And then everything else is kind of open to Yeah, depending on your athlete. So yeah, don’t hang away off your head.



Yes, that is fabulous advice. And now as we start to wrap things up, I’m going to ask you the question that I asked everyone, and that’s knowing where you are now in your life and career. What advice would you give to yourself as a new grad right out of physio school, your younger self?



I think that’s a great question. And I don’t regret anything that I’ve done in my career, but I would say that I’ve probably come to really specializing in neck strength is a bit too late. So we started in the early 2000s. So my first paper was published in 2005. And as I say, I got distracted doing other things. And I wish I’d continued with it. And I didn’t partly because I was having children, and I’d moved to Australia and just life got in the way. And when I came back to it in the probably about 2015 16. So 10 years later, and nothing had moved forward, really. And I just thought that was a really missed opportunity. And so I if I could go back in time, I would probably, yeah, I would probably want to squash those 10 years into maybe 18 months.



Well, that would be pretty amazing time traveling. So where can people find you? If they have questions, they want to follow you on social media, where can they go.



So the best place to find me is on Twitter. So I’m at peak underscore Carey, I don’t tweet about anything other than my research. So that’s the best place to find me. And then you can always drop me a message through there. Otherwise, you can probably find me via Google, at my email address at the University of Sydney.



Perfect. And just so everyone knows, we will have a link to the papers that we’ve mentioned today. So if you want to read up on those that don’t worry, they will be in the show notes at podcast at healthy, wealthy, smart, calm. And Carrie, I want to thank you for coming on. Like I said, I really loved your presentation in Monaco, which was just a short snippet of kind of the amount of things that we talked about in the podcast today. So thank you so much for taking the time out and coming on.



No, thank you actually went to your presentation in Monaco as well. And you’ve informed a lot of what I do as well about, you know, I think that most research is quite ego driven. And I’m not an exception to that. And we think that if we publish a paper that somebody is going to read it and we’re going to change the world. And that rarely happens because players and coaches don’t read research. And so your presentation was about you know, engaging with the media and doing a lot more in the social media space. And that really hit home to me that we have to try and bridge that gap if we can to translate research to practice. So no, thank you.



Oh, well, that’s nice. I’m glad to hear that I will pass that along to my partner Osman, as well. So thank you for that. And again, thank you for coming on. I really appreciate it. And all of you listening. Thanks so much for tuning in. Have a great couple of days and stay healthy, wealthy and smart.

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©2019 Karen Litzy Physical Therapy PLLC.
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