[Case Studies] When gait retraining helps patellofemoral pain with Dr Bradley Neal

In this episode with Dr Bradley Neal, we explore an interesting case study on a real patient of his - a runner who was experiencing patellofemoral pain. We cover:

• The role of gait analysis and key aspects to look out for
• Treatment of patellofemoral pain using gait retraining
• Forefoot striking vs rearfoot striking
• Step rate vs stride length retraining

This episode is closely tied to Brad’s case study he did with us. With case studies, you can see how top clinicians manage real-world cases and apply their strategies to get better results with your patients.

👉🏻 Watch Brad’s case study here with our 7-day free trial: https://physio.network/casestudy-neal

Dr Bradley Neal is a Lecturer in Physiotherapy at the University of Essex, a Post-Doctoral Research Fellow in Sports & Exercise Medicine at QMUL, and a Visiting Lecturer at the University of Hertfordshire. With a PhD on lower limb biomechanics and patellofemoral pain, he spent 10 years as a Specialist Musculoskeletal Physiotherapist and Head of Research at Pure Sports Medicine, London. His research focuses on patellofemoral pain, knee pathology, running-related injury, and musculoskeletal biomechanics.

Reference to paper discussed in this episode here - Neal BS, Lack SD, Bartholomew C, et al; Best practice guide for patellofemoral pain based on synthesis of a systematic review, the patient voice and expert clinical reasoning. British Journal of Sports Medicine 2024;58:1486-1495.

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Our host is @James_Armstrong_Physio from Physio Network

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Transcript

SPEAKER_01 0:02

Today on the Case Studies podcast from Physio Network, I'm joined by Dr. Bradley Neal, Advanced Clinical Academic Fellow in Precision Musculoskeletal Medicine at Queen Mary University of London. Brad spits his time between clinical practice as an advanced practice physiotherapist and academic research, and also serves on the editorial boards of Physical Therapy and the Knee. He's an elect board member of the International Patellophemoral Pain Research Network and a recognised expert in the field of knee pain. In today's episode, we are going to dive into a fascinating case from Brad's clinical experience, a runner with patelephemoral pain, something that many of us have seen many times in practice. And in this episode, we explore particularly how and when to use gait retraining. We discuss step rates and queuing, strategies, and unpack the potential mechanisms behind how these interventions may work. So if you want a better understanding of how to apply gait retraining in practice and refine your approach to managing patellophemoral pain in runners, you will not want to miss this one. I'm James Armstrong and this is Case Studies. Brad, welcome to the podcast on case studies today. It's great to see you, great to have you on the podcast. No, thanks, James. Pleasure to be here and looking forward to having a chat. Brilliant. Many listeners probably all are already aware you've done a great case study for Physio Network, but some of them won't be. So we're going to just cover a little bit of it today, but we're going to go into more detail around gate retraining and patelephemoral pain, which is going to be right up your wheelhouse given your authoring with Simon Lackand, Claire Bartholou, and Dylan Morrissey, I think it was on the best practice guide for patelephemoral pain, which I'm sure we'll touch upon as as well at some point. So let's dive into the case study then, Brad. Do you want to give us a bit of an overview of the case that you had for your physio network case studies?

SPEAKER_00 1:54

Of course. And this is a case that I've used a lot when I teach over the years, having been doing this sort of thing now for over 10 years. And because I'm still using it, I think it's a case clearly that still holds value, at least in migray matter. So the person in question here was a runner with patelephemoral pain. And a runner who had, like lots of runners with patelephemoral pain, had symptoms for a long time. We're talking a number of years. Symptoms that waxed and waned dependent on how much she was doing. So if she wasn't running, her knee was pretty quiet. Any attempt at running, that was when her knee started to remind her that something wasn't quite right. And someone that had done lots of things in the past without any particular success.

SPEAKER_01 2:45

Okay. So you'd been through other trialing other things and not had too much luck with it over the time.

SPEAKER_00 2:51

Yeah, and importantly, I always say that it's definitely easier to be the second person through the door, right? And in this case, I think I was something like the fifth or sixth person through the door. This patient in question had seen lots of clinicians. And an important tip, I think, for all clinicians, but perhaps for some of our newer clinician colleagues, when someone's seen a previous clinician, be it a physiotherapist or otherwise, it's really important to sort of spend time understanding what has come before. For a UK context, that failed physiotherapy mantra that you sometimes see on referrals. Well, what physiotherapy have they failed? Have they had high value care? Have they had low value care? Yeah, it's really important to get into those details. And in this case, the patient in question had done lots of good exercise-based therapy. She'd done lots of things that I would have done too had I gone down an exercise route, and she'd clearly been adherent to those things and still hadn't improved. So that was part of what made it very easy to bring in run retraining as something different that she hadn't tried before.

SPEAKER_01 3:58

And which is key. And also what was interesting about this case as well, Brad, but that this patient has some potentially quite negative terminology, diagnosis views as well from an MRI scan, and also advised poorly to stop running or forget about returning to running.

SPEAKER_00 4:15

Yeah, quite right. And something that does still happen. It certainly happens here in the UK where we both are. In this case, the advice came from an orthopedic surgeon. I think it's important to clarify that I've seen lots of patients who have told me that they've been advised that running isn't for them and that isn't something that just orthopedic surgeons say. I've heard physiotherapy colleagues say it, I've heard GP colleagues say it. It is quite a common mantra of runnings, maybe not for you. For Kylie, in this case, it was linked to that synonym of patelephemoral pain of Chondromalacea patelli, which within the sort of international group of patellophemoral pain researchers, we've been trying to push that term away for quite some time now, partly because it's essentially a radiographic diagnosis. You can't diagnose chondromalacea patelli unless someone has had a genuine quantification of their cartilage, be that with MRI scan or with arthroscopy. And even if someone does have a degree of chondromalacea patelli, all that tells you is the objective state of their cartilage. It tells you nothing about them as a person, their pain complaint, their diagnosis. So it is a term that people will hear, but it's one that we try and discourage as a diagnostic term because it is quite a no stebic sounding term, isn't it?

SPEAKER_01 5:31

It is, it's a complex term, and if I quite often find with patients, if it sounds really complex, it sounds really worrying, and it's just not helpful. So this is potentially could have been quite a tricky patient. They've been through, they'd had some good, potentially good interventions, things you'd have done before. They'd had some negative diagnoses and advice. So you you had a bit of work to do with this patient. So talk us through where you set your stall out.

SPEAKER_00 5:57

Where did you go to and what made you think that for run retraining, particularly, for me, when I see a runner with patelephemoral pain, my mind automatically goes to if there's no strength deficit, so that's the first thing to say. I did a very typical assessment for me of someone with patelephemoral pain, and that involves objective strength testing of the quadriceps and the hip musculature. There was no objective difference. Kylie had unilateral symptoms, which made it very easy to compare her symptomatic side to her asymptomatic side. It's slightly easier for the quadriceps if we need to lean on normative data, but we generally work off of 30% of body mass for hip extension and 25% of body mass for hip AB duction if we've got unilateral symptoms. But because her symptoms were so run specific, where she wasn't running, she was active in the gym. She was an active person, she was using the gym, she was cycling, she was doing lots of things. So there was no reason for her to be objectively weak. And because that wasn't the case, when we see such run-specific symptoms, I automatically think this must be to do with either how much you're running or the way that you're running. And in Kylie's case, she hadn't run for six months prior to coming in to see me. She was stuck in this boom and bust cycle of I try to run, my knee gets grumpy, I stop running, all my day-to-day symptoms go away. I try again, wash, rinse, repeat. So she hadn't run for six months before coming in to see me. And genuinely, her exact words were if you can't help me, I'm gonna give up on running and accept what I've got. So it was easy to do something different, and it was easy to think this must be to do with how you're running, because it couldn't possibly have been how much.

SPEAKER_01 7:51

Yeah, absolutely. She made that easy for you in that sense, which is good. So when we talk about gate retraining, it it is a term your gate analysis, gate retraining, it's a term used widely, I think, amongst healthcare professionals, but also amongst running coaches. And I think there's quite a lot of variation in terms of what we're doing and what we're looking for. So starting with that gate analysis. I mean, obviously, we we could go into a whole podcast on gate analysis, but were there any key things that you looked for that would inform your ability to look at and appropriate gate retraining?

SPEAKER_00 8:28

Absolutely. I can make that part very easy in that I now look only for one thing. So I love biomechanics. I always have. I've done lots of biomechanics research. I spent a lot of time in a biomechanics lab during my PhD. I'm at the point with my clinical reasoning whereby I don't think biomechanics are as important as I used to think, and certainly not as important as some people seem to think. And part of that is because we have to accept in a clinical world, we can't come close to quantifying what we are able to quantify in a gate lab, right? So the final chapter of my PhD thesis was looking at an attempt to validate 2D cameras relative to a 3D motion capture system. And even in the sagittal plane, so side-on flexion extension, which in theory should be the most straightforward plane, 2D cameras don't come close, basically. They aren't valid and they aren't, they certainly aren't interrator reliable. They're on the way to being intra-rator reliable, but they're not valid, and that's the most important thing. There's no point having a set of scales that can weigh you correctly time and time again if they're not actually telling you how much they weigh. So, from a clinical gate analysis perspective, I purely look at side-on footage. So sagittal plane, side-on, and I'm looking for one simple metric which is does that person overstride or not? So it's difficult to talk through this in some ways without some actual imagery which we do have in the case study. But in essence, if your foot is ahead of your knee, regardless of how fast you're running, or the pace you're maintaining, or your cadence or step rate, slightly different terms, with interchangeable meanings. If your foot lands ahead of your knee, you have an overstride, and therefore are amenable to the types of retraining interventions that I use.

SPEAKER_01 10:33

Ever wished you could see how experts treat real patients of theirs? With case studies by Physio Network, you can. Watch presentations where top clinicians break down real-life patient cases step by step, showing how they assess and treat even the trickiest of conditions. It's the best way to improve your clinical reasoning and build confidence in the clinic. Click the link in the show notes to start your free trial today. Brilliant. Okay. So leading us lovely, really nicely on to onto what that might look like. So we've you've really simplified their the gate analysis, which I think is really useful because, as you mentioned, I'd say majority of clinicians do not have access to anything close to 3D gate labs. So having something that can simplify it for themselves is great. So then how do you take that into gate retraining and what does that look like? And what do we know about the effectiveness of that?

SPEAKER_00 11:27

So the way I do it with patients is having quantified their stride length and essentially made that a binary thing, are they over striding or not? My retraining intervention always starts with cadence or step rate. If we want to be pedantic, step rate is both legs, cadence is one leg. So clinically, most of the time, people are talking about step rate, so we'll try and consistently use that going forwards. I always lean on step rate retraining first, primarily because it has the most evidence and it seems to have the least potential for harm or secondary problems. So there are many things you can do to reduce step length, right? You could get someone to try and land on their forefoot, presuming they're not already doing that. You could look to get them into minimalist shoes, you could look to use an incline on the treadmill to try and shorten stride length. All these things have been tested and they've been tested a lot in normal people, and we know that all these different cues will change run by mechanics, and they will change length of stride relative to a given pace. But if we look at the data we have in people with patellophemoral pain, for example, foot strike retraining does have the potential for Achilles tendon pain, calf complex pain as a secondary consequence. About 25% of people will have plantar flexa pain after switching to a four-foot strike pattern. Whereas at the moment, with the data we have, it doesn't seem to happen with step rate retraining. So that's why it's my go-to. And the way to do that clinically is having quantified overstride. If we know the pace that someone's running at, so make a note of what they've set the treadmill at and let the patient guide, have a quantification of their step rate, and that is as simple as count how many times their foot hits the treadmill belt in 15 seconds, multiply it by four. You've got a step rate expressed over 60 seconds, which is fairly standard, and we then look for a percentage increase. You give them a metronome set at a percentage above that baseline, and we normally land at 7.5% as being the sort of magic number that seems to help give people a progressive run program that they can follow and monitor for symptom change.

SPEAKER_01 13:54

Brilliant. Okay, right. So that's good. The first come question that comes to me is off a treadmill. So when you're sending that patient away and they're you're in mid of spring summer, and you've got those two days of sunny weather in the UK, and the patient wants to run outside, how would you explain to the patient or give the patient the tools to be able to do that maybe on a on a run through their village?

SPEAKER_00 14:18

The easy answer is for at least six weeks, I don't let them because step rate retraining outside, all that happens, and normally most patients get this when you explain it to them. If you increase step rate without controlling for speed, all that happens is people run faster and they tire quicker and nothing good happens. So you need a period of learning where by maintaining a higher step rate at a fixed pace can become your semi-normal. And that happens quite quickly. The studies we've got, some of the work that we've done in our lab and other labs around the world. Six weeks is a long enough period for people to sort of habitualize to an increase in step rate. And that's partly why we think it's important that you do a phased program. So as the amount of running gradually increases, the amount of feedback gradually needs to reduce. So use the metronome less often, in simple terms, so that we learn those new mechanics. If you use the metronome all the time, you'll be very good at running to a metronome. You'll find it really difficult once the metronome is taken away. And then providing at six weeks plus or minus, when we retest, if we're seeing positive symptom change and we're seeing habitualization, then you can start to take it outside. And the way I do that is you do a run on the treadmill and at a fixed pace, for example, 30 minutes, because that's the week six run in the program that I use on the treadmill, 30 minutes at that pace, you've gone, let's say, nice and simple, six minute kilometers, you've run 5k. If you then go and do that outside and find that in 30 minutes you run near a 6k, you're clearly running faster. So there's no way you've maintained that step rate. So you've got to go back to the treadmill, try again, take it outside, and once your outdoor runs match your treadmill runs, you've then probably got it over ground and you can build from there.

SPEAKER_01 16:17

Perfect. Perfect. So lastly, so looking at why is this making a difference? So what are the potential mechanisms for for this?

SPEAKER_00 16:26

The way I explain it to patients, and this is simplified, and that's important when we're talking to patients, is I link it all down to ground contact. So if we think about an elite runners don't tend to get patelephemoral pain, that's the reality. They break down with other things. It's normally foot and ankle for elite runners, but elite runners don't tend to get patelephemoral pain. And elite runners are elite because they spend as little time as possible on the ground. They touch the ground for a shorter period of time as necessary in order to maintain their given pace. So when we increase your step rate at a given pace on the treadmill, you're going to be in contact with the ground for a shorter period of time. There's going to be less load going through your knee, and that should reduce the potential for irritation within your patellophemoral joint. Sometimes I'll say, imagine someone in a boxing max, and imagine you take a punch that hits you square in the face that you keep walking into is going to hurt an awful lot more than one that glances off of you as you try and get out of the way of it, right? Think about a basketball athlete trying to dunk a basketball. If they spend loads of time on the ground, by the time they start to jump, a defender's there and then knocking the ball away. Whereas if you can jump really high without being on the ground for a very long time, you'll probably get the ball in the basket. I've got a number of different analogies that I'll use with patients, but it's all linked to that very simple paradigm of if you're in contact with the ground less, there's going to be less load going through your knee. That should keep your patellofamor joint happy.

SPEAKER_01 18:04

Yeah, brilliant. And as I say, you also find that do you in terms of forefoot and rear foot strike, do you see anything around that at all? I just want to touch on that because if you're increasing that step rate, are you doing anything to that necessarily?

SPEAKER_00 18:18

You generally will, and it's the reason that I don't personally find step rate retraining that beneficial, because the foot is attached to the tibia or the foot segment is attached to the shank segment, if we want to think biomechanics language. And if you overstride, so if you land with your foot ahead of your knee, it's really difficult to get anything but your heel on the ground. And then if you land with your foot underneath your knee, unless you've got a very mobile ankle into dorsal flexion, it's very difficult to get anything other than your midfoot or your forefoot on the ground. So I tend to find that foot strike will change organically with length of stride. Over stride is generally heel strike, controlled stride is generally midfoot or forefoot, and wherever someone ends up, I aim to leave that alone. That's the reason I don't find foot cues as beneficial as some people seem to.

SPEAKER_01 19:18

Yeah, absolutely. Brad, this has been brilliant. I wish we had more time, but I think listeners who haven't checked out the case study that you've done, I think there's a whole wealth of information. The slides are all available if you took the case studies, which has got everything from the diagnosis, differential diagnosis, and everything in between, all the way through to the to the treatment and gate retraining with the athlete that you've mentioned today. So, Brad, thank you very much for your time. It's really great to have you on. I'm sure we'll have you on again in the near future. My pleasure. Thanks again for having me. Thanks, Brad.