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Melanie Cole, MS (Host): Are you interested in having your patients evaluated for improved coordination and optimization of care? Today, we're highlighting the utility of 3D gait analysis in the treatment of pediatric neuromuscular conditions. Welcome to UF Health MedEd Cast with UF Health Shands Hospital. I'm Melanie Cole. And joining me today is Dr. Kirsten Norell. She's an Assistant Professor of Pediatric Orthopedic Surgery in the Department of Orthopedics and Sports Medicine at the University of Florida College of Medicine, and she practices at UF Health Shands Hospital.

Dr. Norell, thank you so much for joining us today. I'd like you to start by telling other providers a little bit about 3D gait analysis, how it differs from traditional methods of gait assessment that we've been doing for years and years. What specific parameters, metrics does it provide that are most useful for assessing these pediatric neuromuscular conditions?

Dr. Kirsten Norrell: So, it is called 3D gait analysis because it analyzes each segment or joint in the sagittal, coronal, and axial planes. So, visual observations of gait at best can identify two-dimensional, usually sagittal and coronal gait abnormalities, looking at a patient walking from the side and then walking straight in front of you, but it's very difficult to understand transverse plane abnormalities such as rotational anomalies. And so, 3D gait analysis is a more specific and measurable representation of all three of these planes of potential deformity. For example, if you look at the knee, the sagittal plane is flexion and extension, coronal plane is varus and valgus, and transverse plane or axial is internal and external rotation. And so, in 3D gait analysis, it's a method to define and quantify the patient's pattern of gait by breaking down each of the gait deviations into segments of the lower extremity and into each of these three planes.

So, what this allows us to do is we're better able to identify each possible cause of the gait deviation; and thereby, recommend strategies to address these abnormalities. And these are both surgical and non-surgical recommendations. So, patients with neuromuscular conditions, they may walk with braces, with or without an assistive device, and all of those patients are candidates for 3D data analysis, but they do need to walk. And then, some of the recommendations we provide with our multidisciplinary team, are there specific targets for Botox? Is there a high level of spasticity? So, maybe we need to get with our Neurology or Rehab Medicine colleagues and improve their tone management. Do they have specific contractures across a joint that maybe need to be treated surgically or with serial casting or with more aggressive physical therapy?

And then also, are there specific brace recommendations that may be beneficial to these patients? Maybe the brace they're currently using is not the optimal brace for their gait deviation, and there's a better or different brace that might give them more stability or better energy transfer if weakness is a problem. Traditionally, 3D gait analysis has been used to assist orthopedic surgery recommendations, but it was really developed largely by a physician who was initially a physical therapist and then became an orthopedic surgeon and did a lot of work with post-polio patients. And it has been around for a while, but it's definitely evolved in its utility to clinicians and that's still being understood.

The different levels of information that we get with 3D gait analysis, it's a very long list of information, and it's a pretty time-intensive process to go through, but we can get kinematic data, which is where we put different markers on bony prominences that we can feel underneath the skin on a patient's body into specific segments. And then, we have these patients walk with specialized cameras, and the computer uses these cameras to then calculate a mathematical representation of each segment in space in each of these three dimensions. And there are normalized parameters that we use as a reference for this data, which is called kinematic data. So, that's where each body segment is in space, the pelvis, the hip, the knee, the ankle, the foot. We also get kinetic data, which is the magnitude and direction of force when stepping onto a force plate, also called the ground reaction force. We get muscle length and activity throughout the gait cycle. So if a muscle is too short, that may indicate a contracture. If a muscle is turning on during an abnormal time in the gait, that could be due to high activity levels that's seen in spasticity or poor selective motor control. And we also do a very detailed physical examination that includes range of motion, strength, spasticity, and selectivity. And these all kind of come together so that we can see what do the graphs show us about the 3D analysis? What can we confirm based on physical exam? Which gait deviations are real and which are a secondary problem? So, which actually need to be addressed and which are compensatory and maybe don't need to be addressed?

Melanie Cole, MS: Wow. That was such a comprehensive answer and that's fascinating technology, Dr. Norell. So, what children might benefit the most? Speak a little bit about age and conditions of the kids that this works the best for.

Dr. Kirsten Norrell: Traditionally, we use this for our cerebral palsy patients, so children who are walking and, like I said, they can walk with braces, they can walk with a walker and we can still do the gait analysis, so patients that are GMFCS 1 and 2. So, those are patients that are walkers with minimal assistance, really can benefit, especially at the time when you're starting to see as they grow, maybe contractures develop or their gait worsening, maybe they're starting to toe walk, maybe they're flexing their knee or they have a crouched gait. Those patients are fantastic for this kind of study, but we can still do it on patients that are more reliant on a walker. The patients that are predominantly in a wheelchair don't get as much benefit from this because it's hard to participate.

In addition, the younger age limit is probably around age five, maybe a little bit older, it depends on the child and their ability to follow instructions, because they do have to be able to follow our instructions for both the walking assessment with the markers and the EMG, as well as for the physical examination portion, there is an interactive part of it, especially when assessing a patient's selective motor control and strength.

In addition to cerebral palsy patients, we are happy if there's ever a gait abnormality that especially if it's something more complex, it's more than one plane of deformity, we're always happy to perform a gait assessment. But other patients that may benefit are muscular dystrophy patients, SMA patients that are still walking, patients that are toe walking, there might be a concern that something else is going on; patients that physician may be interested in if they are a candidate for selective dorsal rhizotomy, which is a neurosurgical procedure to decrease spasticity. We can assess if they have enough spasticity, it's inhibiting their gait, and do they have enough strength that they're a good candidate for that type of procedure.

So, it really is a wide variety, and also is applicable to patients that may not even need surgery yet. So, sometimes we have patients referred to us because of a concern that they've tried a couple different bracing options, none of them seem to be helping their gait, and a physician wants to understand what's going on? Why isn't their gait improved? Or is it improved with the brace? Is there a different brace that we may recommend?

Melanie Cole, MS: This is just so interesting to me, how has this technology helped to not only assess the child, but monitor their progress and then make adjustments to their treatment plan over time. What have you seen while using it?

Dr. Kirsten Norrell: So, in addition to providing both bracing therapy, surgical recommendations, we do have the ability to get a gait study prior, give recommendations on an intervention, and then do a followup six months or a year later and see if the intervention, such as surgery, did help. Or if it's like a bracing recommendation, we could even do it sooner once they get their new brace and, in real time, kind of monitor their progress. It is also a check for us because, say, we make a surgical recommendation, sometimes when you do surgery, you may uncover a different level of deformity or a different problem.

The goal of 3D gait analysis is to not have any of those kind of surprises and to identify every level of deformity. But you can't 100% predict how someone's going to recover after surgery. And so, it can be a checkup in six months or a year after surgery to see how they're doing, see how much benefit they got, see if there's anything else that we can recommend to help them in their recovery process. We also are using this information to basically build a database for us to go back to both for research and to look back and track people's progress as they get multiple gait studies. Because if we start seeing a child around five or six years old with cerebral palsy, we may do a few gait studies during their growth as different problems arise, which is the natural history of having cerebral palsy in a growing child, that as they grow, more contractures, more issues may arise due to the difference between bone length and the muscle spasticity and ability to compensate for that increased bone length with growth.

Melanie Cole, MS: Wow. The technology really is something and it's moving so quickly. It's such an exciting time in your field, Dr. Norell. As we wrap up, what would you like to let other providers know? Your key takeaways about this 3D gait analysis for families, how you're helping them, how you're involving them in the shared decision-making for their children based on this exciting technology.

Dr. Kirsten Norrell: So whenever we are doing these gait analyses, we do have patients and/or their caregivers, depending on the ability of the patients based on age and their individual, understanding, fill out patient-reported outcomes and a goals questionnaire for the cerebral palsy population. And what that does is we can look at their specific goals and try to focus on those goals in our recommendations, so that we are addressing what the patient and the family are most concerned about. Because sometimes it may be more about improving activities of daily living more than how far can they walk or how normal is their gait.

And in addition to that, we have a multidisciplinary team that meets one to two times a month, depending on how many gait studies we have done to review all the studies, come together as a team and get multiple different specialties input so that we can address all levels of the patient's care. So, it's not just me giving surgical recommendations. We have our rehab colleagues that can provide some tone management recommendations, orthotic recommendations, and we have therapists that we work with as well as our engineer to help us understand if there's any questions that arise with some of the data. We can go back, we can look into things, make sure there isn't an error in a marker placement, that the gait abnormality that we may be seeing is a true gait abnormality. So, there's a lot of different levels that we can go, we can recheck, we can confirm that everyone agrees with the final report, the final recommendations. And I really believe it is a very important multidisciplinary tool to help us provide the highest level of care to patients with neuromuscular disorders. And it is not exclusive to cerebral palsy.

Melanie Cole, MS: What a great conversation. That was so eye-opening for providers that didn't know about this technology. Thank you so much, Dr. Norell, for really educating us today and giving us some great information about 3D gait analysis. Thank you again. And to learn more about this and other healthcare topics at UF Health Shands Hospital, please visit innovation.ufhealth.org or to listen to more podcasts from our experts, you can always visit ufhealth.org/medmatters. That concludes today's episode of UF Health MedEd Cast with UF Health Shands Hospital. Please always remember to subscribe, rate and review UF Health MedEd Cast on Apple Podcast, Spotify, iHeart, and Pandora. I'm Melanie Cole. Thanks so much for joining us today.