Hello, everyone. My name is Ajay Patel, and I'm a resident physician at New York-Presbyterian Hospital, Columbia University, and Weill Cornell Medicine in New York in the Department of Physical Medicine and Rehabilitation. I'm here with Dr. Pratik Grover from Washington University School of Medicine, Department of Neurology, along with his colleagues from Washington University School of Medicine to present to you a gait analysis and rehabilitation lecture. Disclaimer, I have no financial conflicts of interest to disclose. My presentation portion will focus on physiologic gait along with pathologic gait patterns. We'll start with physiologic gait. We'll review some definitions and basic terminology, then go through the phases of gait, review muscle action during the gait cycle, and then discuss energy expenditure. What is gait? Gait, by definition, is a series of rhythmic, alternating movements of the limbs and trunk that results in forward progression of the center of gravity. Gait is dependent on visual, vestibular, cerebellar, motor, and sensory inputs. Gait is meant to be energetically efficient. Reviewing some basic terminology, we'll start with center of gravity. Humans have a center of gravity that is located about two inches in front of the S2 vertebrae in our spine. We'll also discuss base of support. Base of support is the space outlined by the feet and any assistive device in contact with the ground. Falling in general is avoided if the center of gravity remains positioned over the base of support. We'll now review some further terminology that's commonly used when describing gait patterns. The first word we'll review is stride. Stride is equivalent to one gait cycle. Stride length, then, is the linear distance between corresponding successive points of contact of the same foot. It's the distance measured from heel strike to heel strike of the same foot. If we look in this picture, we can see that stride length is measured from the heel of the left foot to the next step of the heel of the left foot. Then we have step length. Step length is the linear distance in the plane of progression between corresponding successive contact points of opposite feet. It's the distance measured from heel strike of one foot to heel strike of the other foot. In the picture, we can see that step length is the distance between the heel of the right foot touching the ground and the heel of the left foot touching the ground thereafter. Next word is step width. Step width is the distance between the center of the feet during double limb support portion of the gait cycle when both feet are in contact with the ground. Step width increases in the elderly and children as they demand more stability. Cadence and walking speed are also other terms that we'll commonly use to describe someone's gait pattern. We'll now review the phases of the gait cycle. We'll start by discussing the stance phase and then move into discussing the swing phase. The stance phase is the time period in the gait cycle during which the reference limb is in contact with the ground. The stance phase accounts for about 60% of the gait cycle. In this example, we'll use the right limb as the example of our reference limb that we'll discuss. The first part of the stance phase is called initial contact. It is described as the instant that the foot contacts the ground. The second part of the stance phase is loading response. Loading response is the time period immediately following initial contact up until the contralateral extremity is lifted off of the ground during which weight shift occurs. The center of gravity is lowest at this point as you are pushing your foot into the ground. The third part of stance phase is mid-stance. Mid-stance is the time period from lift of the contralateral extremity from the ground to the point where the ankles of both extremities are aligned. The center of gravity is in fact the highest during mid-stance as you are standing tall on one leg. As a side note, when we're running, our center of gravity is actually the lowest in mid-stance as you're vaulting yourself forward. The fourth part of stance phase is terminal stance. Terminal stance is the time period from ankle alignment just to initial contact of the contralateral extremity. The last part of stance phase is called pre-swing. Pre-swing is the time period from initial contact of the contralateral extremity to just prior to lift of the ipsilateral extremity from the ground. An easy way to remember the components of stance phase is to use this mnemonic, I like my tea pre-sweetened, using the first letter of that mnemonic to help you remember the five parts of the stance phase. It's important to also discuss single limb support and double limb support in regards to the gait cycle in this section. Single limb support is the portion of the gait cycle in which only one limb is in contact with the ground. This is approximately 80% of the gait cycle. It includes mid-stance and terminal stance. The portion of the gait cycle during which both limbs are in contact with the ground is called double limb support. This is approximately 20% of the gait cycle. This includes initial contact, loading response, and pre-swing. The amount of time spent in double limb support decreases as the speed of walking increases. When there is no longer a double limb support period, the person is considered to be running. We'll now discuss swing phase. Swing phase is the time period during which the reference limb is not in contact with the ground. This accounts for about 40% of the gait cycle. Three components of the swing phase are initial swing, mid-swing, and terminal swing. Initial swing is the lift of the extremity from the ground to position of maximal knee flexion. Mid-swing is immediately following knee flexion to vertical position of the tibia. And then terminal swing is following vertical tibial position just prior to initial contact. And then you move back into stance phase. An easy mnemonic to remember the different parts of swing phase is to use the mnemonic in my teapot. We'll now discuss muscle actions during gait. A lot of our lower extremity muscles are involved during the gait cycle, and these include our hip extensors, hip abductors, hip flexors, and hip adductors, alongside the knee extensors, knee flexors, ankle dorsiflexors, and ankle plantar flexors. They provide a balance between concentric and eccentric contractions of the lower extremity to allow us to participate in the gait cycle. We'll start by discussing the importance of the hip extensors and hip flexors in gait. The hip extensors are involved in early stance as well as late swing. In early stance, you'll see concentric contraction of the hip extensors to control hip and knee flexion and stabilize the limb. In late swing, you'll see concentric contraction to extend and to stabilize the limb in preparation for weight bearing in stance phase. The hip flexors, on the other hand, are involved in late stance phase and swing phase. In late stance phase, the hip flexors are activated eccentrically to slow and control posterior rotation of the thigh. In the swing phase, the hip flexors concentrically contract to initiate hip flexion and accelerate the swing limb forward. We'll now discuss knee extensors and knee flexors. Knee extensors are involved in initial contact and loading response along with late stance and early swing phase. Knee extensors and initial contact and loading response are activated eccentrically to control knee flexion and prevent buckling. In late stance and early swing phase, the knee extensors eccentrically contract to control collapse of the knee and prevent early heel rise. The knee flexors, as we can see, are involved in late swing phase and early stance phase along with early and mid swing phases as well. In the late swing phase and early stance phase, the knee flexors contract eccentrically to control knee extension and stabilize the limb before weight bearing. In early and mid swing phase, concentric contraction of the knee flexors occurs in swing phase to produce knee flexion and facilitate foot clearance in the swing phase. The ankle dorsiflexors and ankle plantar flexors are also important when discussing muscle activation in the gait cycle. The ankle dorsiflexors are involved in early stance phase and swing phase. In the early stance phase, the ankle dorsiflexors eccentrically contract to control ankle plantar flexion and loading response. In swing phase, concentric contraction of the ankle dorsiflexors occurs to facilitate foot clearance during the swing phase. Ankle plantar flexors are important in stance phase. In the mid stance phase, eccentric contraction of the ankle plantar flexors occurs to control ankle dorsiflexion moment and prevent excessive forward tibia rotation. In terminal stance phase and pre-swing phase, the ankle plantar flexors concentrically contract for push-off and acceleration of the swinging limb. Energy expenditure and gait. Gait at customary walking speed is less energy intensive than 50% VO2 max and below anaerobic threshold. The gait energy expenditure during stance phase is approximately three times more than that of swing phase. In general, total muscle energy expenditure is more in double limb support than single limb support. Highest energy consumption during the gait cycle occurs during first double limb support, and the lowest energy consumption is during second double limb support. In regards to muscle energy consumption, the hip extensors are by far the biggest users of energy during the gait cycle. We'll now discuss determinants of gait. Determinants of gait were created in the 1950s to help describe strategies to achieve the most energy efficient and graceful gait through minimizing the movement of the center of gravity in a vertical and horizontal plane. The components of the determinants of gait include pelvic rotation, lateral displacement of the pelvis, pelvic tilt, knee flexion, knee mechanisms, and foot mechanisms. Pelvic tilt and knee flexion are important to reduce vertical displacement during the gait cycle. In regards to the vertical displacement of the pelvis, displacement toward the stance limb will occur to keep the center of gravity above the stance foot. Pelvic rotation and lateral displacement of the pelvis also occur to reduce displacement during the gait cycle. Pelvic rotation is important because the pelvis will rotate medially on the swinging leg side, which will lengthen the limb as it prepares to accept weight. This reduces the angle of hip flexion and extension. It enables a slightly longer step length without further lowering the center of gravity. Knee mechanisms and foot mechanisms can help decrease lateral displacement during the gait cycle. In regards to knee mechanisms, the knee extends as the ankle plantar flexes and the foot supinates to restore the length of the leg. Losses in energy expenditure occur in the younger population as well as the elderly. In the children and elderly, abnormal lower limb kinetics, including uncoordinated movements, weak muscles, and decreased range of motion, make gait more energy consuming. Energy expenditure will also increase with speed. Physical loads can incur greater expenditure during the gait cycle. Assistive devices can help balance energy expenditure and stability. Increases in energy expenditure are also seen in pathologic gait patterns. We'll now discuss different assistive devices that can aid in the gait cycle for different patient populations. We'll first talk about different types of canes. The C cane, as shown in the picture, is the most common cane used. The quad cane, also seen, provides an increased area of support compared to the C cane. The type of cane that you choose is determined by the type of gait disturbance. Is it a balance issue, a motor issue, or a joint problem? These are all factors that you want to consider before choosing a cane for your patient. A standard cane can be used in patients with vestibular dysfunction, visual impairment, or sensory ataxia. A C cane is used in patients who need slight assistance with balance or minimal unweighting of the opposite leg. Functional grip cane allows for better support and are appropriate for patients who need more balance assistance than a C cane. A quad cane is for people that require max balance assistance. When picking a cane, you want to measure the tip of the cane to the greater trochanter in a patient in an upright position. The elbow should be flexed about 20 degrees comfortably. A cane is used on the opposite side of the supporting lower limb. It advances with the supporting lower limb. When navigating stairs, we'll often use the phrase up with good and down with the bad to indicate which foot should lead which during the gait pattern while walking up the stairs. A cane can increase stability during the single limb support phase. It can also increase energy expenditure in healthy young users and can decrease energy requirements in healthy older subjects. Increased energy expenditure in younger populations is likely due to poor use of the assistive device itself. We'll next discuss crutches. A crutch provides support from the axilla to the floor. Crutch length is measured as the distance from the anterior axillary fold to a point about six inches lateral to the fifth toe with the patient standing. The hand piece is measured with the patient's elbow flexed about 30 degrees with the wrist in maximal extension and the fingers forming a fist. This is measured after the total crutch height is determined with the crutch three inches lateral to the foot. Crutches are not designed to be rests for body support. Using it as a body support device may increase your risk for radial nerve neuropathies due to compression under the arm. Crutches promote swing through gait that is more energy intensive, but also more efficient due to increased speed. Your gait velocity using crutches may increase, but you may appear to be less stable. When we discuss different patterns of gait while using crutches, we often describe a step to gait pattern or a step through gait pattern. A step to gait pattern can be seen in the pictures described two points, three points, and four points. A two point step to gait pattern is described as the crutch and the lower limb moving first and then followed by the crutch and the opposite lower limb. And you can see this depicted in the picture described two points where you have movement of one crutch and one foot followed by another crutch and another foot. The three point movement pattern is when you move one foot and both crutches followed by the other foot. Four point gait pattern is when you move one crutch followed by a leg followed by the other crutch and followed by the other leg. This is also depicted in the image below. A swing through gait pattern while using crutches is when you first move the crutches forward followed by both feet past where the crutches landed and then landing on both feet followed by moving the crutches again in a forward position. This essentially swings you through the gait cycle while using crutches. We'll next discuss walkers. When deciding what type of walker to use, start by placing the walker one foot in front of the patient. It should be partially surrounding the patient. Determine the proper height by having the patient place their arms to their side and elbows flexed 20 degrees. A walker provides maximal support but also necessitates a slow gait. It is useful for patients with ataxia and hemiplegia. The design of a walker influences energy cost. A rollator minimizes energy costs compared to a non-wheeled walker. A standard walker has four legs with rubber tips that come into simultaneous contact with the floor. It requires a slower controlled gait pattern. It's useful for patients with moderate to severe cerebellar ataxia, but the need for attention makes them less desirable for cognitively impaired patients. Non-wheeled walkers are best for patients with gait that is too fast for a standard walker or who have difficulty lifting a standard walker. Wheels permit a more normal gait pattern but also decrease stability. It can be used with patients with moderate to severe Parkinson's, frontal lobe-related gait disorders, or moderate ataxia. A four-wheeled walker is used if the patient requires a larger base of support and does not rely on the walker to bear weight. If a patient applies full body weight through a four-wheeled walker, the device will roll and can cause a fall. These walkers are best for higher functioning patients who walk long distances and require minimal weight bearing. Let us move on to Gait 102, Connecting the Basic Science of Gait Analysis with Rehabilitation. We'll talk about three main things. We'll talk very briefly about motor planning and control for gait, then we'll move on to biomechanical approach to gait analysis, and finally, a little bit about functioning frameworks and measurements. Motor planning and control of gait imbalance is a very large topic. This slide attempts to present an overview of the feedback loop and the feedforward loops that exist in motor planning and control of gait imbalance. The easiest way to conceptualize is to think about sensory inputs from the different sensors, followed by supraspinal control in terms of perception and association areas, conceptualization, planning and motor programming, and activation, followed by spinal control with central pattern generators and ultimately resulting in motor task execution. It is important to note that the motor task executed results from volitional and emotional initiation, automatic postural control, and muscle synergies. Now let us turn our attention to the biomechanical principles of gait analysis. When we think about the functions of gait, there are four main ones that have been presented by Jackie Perry. The first one is movement or propulsion, the second is shock absorption, the third is stability, and the fourth is conserving energy, because we want gait to be efficient and we want it to be energy conservative. When thinking about the body for gait analysis, we can think about it as comprised of a passenger unit, which weighs about 70% of the body weight, and the locomotor unit, weighing about 30% of the body weight. The passenger unit is comprised of the head, arm, and trunk, and the locomotor unit, which moves us forward, is comprised of the pelvis and the lower limb. The stick figure can be used to analyze gait. So when we think about a locomotor segment, we can think about the thigh, the leg, and the foot as being rigid segments. And the connections between them, the joints, can be thought of as nodes, and so what happens is that the rigid segments move about the nodes or the joints. This movement of the segments about the nodes or the joints can happen in three planes, the sagittal plane, the coronal plane, and the transverse plane. The movement of these segments about the nodes can now be analyzed in the three planes for each of these specific phases of the gait cycle that we saw in the first section of this presentation. Understanding the movement of these segments around the nodes during the phases of gait, it can be conceptualized by the term kinematics. What we also often analyze in observational gait analysis are spatial-temporal parameters, which is, what is the locomotor unit doing, and the passenger unit doing for that matter, in terms of space and over time. It is also possible, utilizing devices such as force plates, to understand what are the forces that are experienced by the joints, and this is referred to as kinetics. Dynamic electromyography helps us understand muscle activation during the various phases of gait that correspond to segment movement and joint forces. And then energetics is the domain in which we try and understand how much of energy is actually expended for a given activity. To elaborate further on spatial-temporal measures, it's important to break them up into spatial measures and temporal measures. So when we think about how the two limbs move, while one limb is in the stance phase, the other one is in the swing, and then it switches, and then it switches again. So what are the limbs doing in terms of space, in the three planes of motion that we talked about, and then what are they doing over time? These comprise the spatial and temporal measures. The table at the top presents common spatial parameters, and the one at the bottom presents common temporal parameters that can be measured using something as simple as a stopwatch. So for spatial parameters, the common ones include the foot progression angle, which is the longitudinal axis of the foot to the sagittal plane line, toe clearance, which is the distance from the hammocks to the floor, step width, which is the distance from one heel to another, step length, which is the distance from right heel to left heel, and stride length, which is the distance from the left heel to the left heel over one gait cycle. The corresponding values to that are presented in the last column in the first table. Common temporal parameters include cadence, which is number of steps per minute, 120 for males, 110 for females, customary walking speed, which is defined as the stride length multiplied by the cadence divided by two. Stance time and swing time formulae are similarly presented here. The key thing with these is that with cadence and customary walking speed, it is relatively easy to calculate these using a stopwatch. The stance time and the swing time may require more dedicated equipment to measure. The second domain is kinematics, where we are looking at the angular motion. And the angular motion for the locomotor unit can be at the hip, presented in blue here, at the knee, presented in red, and at the ankle joint, presented in green. And what we see in the orange bar here are the stages of the gait cycle. So initial contact, loading response, mid-stance, terminal stance, pre-swing, initial swing, mid-swing, and terminal swing. And I'm not really going to go into the specific movements that happen, because we covered it in the first section, but I think it is really important to stress that to be able to do good observational gait analysis, it is important to try and look at one joint in one plane at a time to be able to understand what sort of deviations are there. Instrumented gait analysis obviously helps us get all of this information in all the planes in a coordinated fashion. The third domain of gait analysis that we are talking about today is kinetics, and it's about forces and moments. So if we look at the circle, which in this case is a node, and think about a force that is acting at a perpendicular distance r, this force generates a moment, m, around the node. And the moment is a vector quantity, and it is denoted by the cross product of the perpendicular distance, r, and the force, F. This knowledge of forces and moments helps us understand the ground reaction force and its role during quiet standing and during mobility. So on this slide, we can see that the ground reaction force is generated upward from the ground, passes through the midfoot, anterior to the ankle, anterior to the knee, posterior to the hip joint, anterior to the thoracic spine, and through the ear canal. And were it not for ligaments that provide passive stability, with the anterior iliofemoral preventing knee flexion and oblique posterior preventing hip extension, the ground reaction force would cause the person to collapse. The direction of the ground reaction force and its perpendicular distance from a joint changes as a person moves through the various stages of gait. The figures here illustrate the location of the ground reaction force at loading response, mid stance, and terminal stance. And as you can see, for the hip, the location of the ground reaction force related to the hip moves from anterior to posterior, for the knee moves from posterior to anterior, and for the ankle moves from posterior to maximal anterior, as people progress from the loading response to the mid stance and the terminal stance. And so, the ground reaction force, by passing anterior to the ankle, generates a moment of the ankle that promotes ankle dorsiflexion, by passing anterior to the knee, generates a moment that promotes knee extension, and by passing posterior to the hip, generates a moment that promotes hip extension. And similar to quiet standing, in this case, it is muscles that provide joint stability by creating balancing moments. The fifth domain that we are talking about today is energetics, and I just want to introduce you to the basic terminology. So when we think about the energy consumed, we can think in terms of the oxygen consumed or the calories consumed. At rest, oxygen consumed is referred to as resting oxygen consumption, and for calories consumed, the term is basal metabolic rate. For any given activity, we think about oxygen consumption, or VO2, and the term metabolic equivalent, or MET, for calories consumed. And then the maximal exertion, the term utilized that we come across very often, is VO2max, or maximal aerobic capacity. How this applies to gait is by two definitions. The first one is physiologic cost of gait, which is defined as VO2 divided by the walking speed, and the physiologic efficiency of gait, which is energy expended by the subject divided by energy expended by normal gait. Now total energy expenditure, TEE, in a 24-hour period, has three major components. The resting energy expenditure, REE, activity energy expenditure, AEE, and thermic effects of food. There are many methods of calculation of energy expenditure. Doubly labeled water method calculates TEE, or total energy expenditure. Direct and indirect calorimetry are used to calculate the resting energy expenditure. Both of these methods are primarily limited to the lab. Calorimetry with predictive equations is often utilized in the clinical setting. And then an example of self-reported measures is the BORG RPE. Where energy expenditure is used clinically is often in discussions with patients who will be using prosthetic devices to be able to talk about what the energy expenditure associated with a given level of limb loss is. Now that we have talked a little bit about the domains of gait, let us turn our attention to common gait analysis methods. Observational gait analysis is often what we do in the clinical setting. It is also possible to use image processing and floor sensors, which is a traditional lab setting, and invariable sensors are a new breed of devices that can actually be utilized in the clinical or community-based setting to track a person's gait, balance, function, and things of that nature. There are several ways to do observational gait analysis. One schematic is presented here, where a square or rectangular space is dedicated for observational gait analysis to allow the subject to move while the observer is able to observe their movement in multiple planes. So, if you think about position one, we can have the subject seated, then they stand, and this allows us to observe their lower extremity strength and balance. Then we have them stand for a few seconds, allows us to observe static balance. Then we have them walk away, turn around, and walk back to position two. And while the person is walking across the room, the observer actually walks along with them, thus observing their movement in the sagittal plane. And then at point two, we actually have them sit down, and this allows us to assess their lower extremity strength and balance one more time. And this can be repeated in the other direction one more time if space permits, thus allowing two good rounds of observational gait analysis. Here are some key points to assist in observational gait analysis. Establish a sequence of observation. Go either from head to toe or vice versa. Focus on one extremity at a time. Note the level of assist and the assistive device used, and then it is useful to actually use some simple devices for measurement, such as a stopwatch. So, presented here is a simple observational gait report that has been adapted from the JAKC Observational Gait Analysis A, Appendix A, pages 230 to 250. So, you will notice that some of the things that we talked about are on this report. So, we have got sit-to-stand, stand-to-sit, assistive device, level of assist, spatial measures, and it is really important to note asymmetry in the stride length, foot progression angle, toe clearance, and step width. And then temporal measures, which can be measured using a stopwatch, such as cadence. Here is an example of a functional test, the 10-meter walk test, and we can possibly measure stance and swing time if we have the devices for it. And then kinematics, measured at the trunk, at the pelvis, on the right and the left side, at the hip, knee, and ankle joint. And again, some of these will be measurable by observational gait analysis. Some of the others will actually require devices. The reason for this observational gait report is not just analyzing, but also thinking through and as an educational tool for understanding gait. Now, looking at the observational gait report on the last slide, we recognize that there are a number of things that we cannot track by simple observational gait analysis. However, a number of these things are clinically relevant. So, an option that is present at certain centers is clinical instrumented gait analysis, where a person is instrumented with markers that can then be tracked by these cameras. And forces can be measured, especially the ground reaction force, can be measured as the person steps across these force plates on this walkway. Instrumented gait analysis is often presented on templates of the kind that is shown here. So, here on this template, you see the phases of gait are presented here. The first five are the phases of stance phase. The last three are the phases of swing phase. And there is a thick line right here that signifies zero. Everything above is positive. Everything below is negative. And so, joint motion, kinematics, joint forces, kinetics, and electromyography, muscle activation, can all be presented on this template and can be analyzed simultaneously for any given phase of gait, which then allows us to make clinical decisions. A good example of this clinical decision-making is pre-surgical planning and post-operative evaluation for bone deformities, such as in cerebral palsy. We will hear more about pediatric gait analysis in the later part of this presentation. Another way to analyze gait is by using variable sensor systems. And so, two systems are presented here that exemplify the kind of measures that can be collected, either in the clinical setting or in community settings. So, here, utilizing inertial motion units, and you see multiple sensors that have been instrumented onto the segments, so here are sensors on the thigh segment, sensors on the leg segment, and sensors on the foot segment. These allow calculation of movement about the joints, thus giving us kinematic measures. And the movement of the person in space and time can give us spatiotemporal measures. And the system on the right side here has sensors that actually are instrumented within the shoe and help us understand the kind of pressures that are generated during movement, an example of a kinetic system. Now that we have talked a lot about gait, let's move on to the next part of the presentation. Now that we have talked a little bit about biomechanical principles of gait analysis, let us bring it back and connect it with co-rehabilitation, which is functioning and measurement. So, presented here is the World Health Organization International Classification of Functioning Disability and Health Model. And if you think about gait as an activity presented right at the center, we recognize that gait can change based upon impairments in either structure or function, and they can result in challenges with participation, such as return to work, driving, recreational activities, and so on. And there is good recognition that gait is affected by environmental factors such as access and by personal factors. The next few slides present some common functional measures of gait and balance. Presented on this slide is the Activity Specific Balance Confidence, or ABC, scale. There are 16 questions on this scale, and the answers in terms of percentage, from no confidence being 0 to complete confidence being 100, determine the percentage impairment. The TINETI test presented here is for balance at the top out of a total of 16 points and at the bottom out of a 12 for gait. And these can be combined for a score of a total out of 28. And the risk of fall is presented on this slide. So, if the total score is less than 19, there is a high fall risk. 19 to 24 is a medium fall risk, and more than 24 denotes a low fall risk. Other common scales used for gait and balance include the Dynamic Gait Index, which is number C here. And as you can see, there are a total of eight domains, and the scale goes from 0 being severe impairment to 0 being severe impairment. To 3 being normal. And this was developed to assess falls and balance in the elderly. And the activities that are measured are gait on level surface, with change in speed, with horizontal head turns, vertical head turns, pivot turn, step over obstacle, step around obstacle, and then finally complete steps. The Functional Gait Assessment Scale, number D here, was modified from the Dynamic Gait Index for vestibular disorders. And as you can see, a number of the domains are same, but they actually added a few domains. So, gait with a narrow base of support with eyes closed and walking backwards was added. And the scale here is actually reversed from the Dynamic Gait Index, with 0 being normal and 3 being severe impairment. Our next section, Gait 103, focuses on pathology of gait. So, we'll start by talking a little bit about the impact, mechanisms, and very high-level overview of management of gait deviations. Then we'll turn our attention to specific pathology of gait patterns, lower limb loss in prosthetics, and then finally cerebral palsy. So far, we have thought about gait from a motor control perspective, a biomechanical perspective, and then utilizing the World Health Organization model. So, when gait is not what it is intended to be, in other words, there are gait deviations. From a biomechanical perspective, gait can become more energy-intensive and lead to decreased stability. Utilizing the World Health Organization model, mobility is impaired, daily activities can be impaired as well. And then participation in the community, such as return to work, driving, and things of that nature can be restricted. And it becomes really important to think about the secondary consequences from gait deviations, such as falls, and then oftentimes people are scared and they may not be moving about as much. And so, consequences of decreased mobility. Gait deviations can be thought about in multiple ways. A simple way to think about is the underlying system and related mechanisms. So, for the musculoskeletal system, there can be challenges with alignment or range of motion. For the neuromuscle system, there can be challenges with tone and motor control. For the purely motor system, there can be challenges with strength. And for the sensory system, there can be challenges with sensory loss and pain. And all of these can be contributory mechanisms to gait deviations. So, just a very high-level overview of rehabilitation strategies is presented here. When there is a gait deviation, the first and foremost thing is to diagnose and manage the underlying medical condition. To address the modifiable causes, such as sedating medications, which are a high-risk factor for falls. And as we talked about, secondary consequences. Providing appropriate assistive devices to maximize stability and minimize energy consumption. Orthotics and prosthetics to augment or replace function. Gait training is really important to optimize gait deviations that have patient-related causes. And then, ultimately, environmental modification often helps to maximize the purpose of gait. Which, remember, is propulsion, stability, and energy conservation. And with that, I will hand it over to the next presenter for the next section. We'll now move on to discuss common pathological gait patterns. We'll discuss an antalgic gait pattern, sensory gait pattern, myopathic and Trendelenburg patterns, neuropathic patterns, spastic patterns, ataxic, and Parkinsonian gait patterns. We'll start with an antalgic gait pattern. An antalgic gait is a gait that develops as a way to avoid pain on an affected limb while walking. It is an abnormal gait where the stance phase of gait is abnormally shortened relative to the swing phase. It is a good indication of weight-bearing pain. Conditions associated with an antalgic gait pattern include trauma, tarsal tunnel syndrome, skiffy, pelvic girdle pain, osteoarthritis, and leg-calf-purse disease. Treating the underlying source of pain with analgesics can help you improve this type of gait pattern or providing the patient with an assistive device to offload pressure from the affected limb. We'll next discuss sensory gait pattern. As our feet touch the ground, we receive proprioceptive information to tell us their location. The sensory ataxic gait occurs when there is loss of this proprioception input. In an effort to know when the feet land and their location, the patient will slam their foot hard onto the ground in order to sense it. A key to this gait involves exacerbation when patients cannot see their feet, which is why we can often test it by turning off the lights and having a patient attempt to walk, of course, with support from a provider. The gait is also sometimes referred to as a stomping gait since patients may lift their legs very high and hit the ground hard. This gait can be seen in disorders of the dorsal columns, including B12 deficiency, tabes dorsalis, or diabetes, which can affect the peripheral nerves, resulting in poor proprioceptive relay of information. To fix this gait, we treat the underlying cause, whatever that may be. A myopathic gait occurs due to weakness of the proximal leg muscles. Myopathies result in a broad-based gait pattern as patients try to compensate for pelvic instability. Patients will have problems climbing stairs and rising from a chair without using their arms. It can be commonly seen in disorders like Duchenne's muscular dystrophy or Becker's dystrophy. And oftentimes, you'll see patients with a positive Gower sign, which is where patients will put their arms and hands to climb up their legs to get up from a seated position on the ground. We'll now watch a video depicting myopathic gait. This gait is a myopathic gait. With myopathies, usually we have weakness in the pelvic girdle region. And as I walk, if I can't stabilize my pelvis, then what ends up happening is that for the weight-bearing leg, I'm trying to stabilize the hip. When I'm coming off of the other, the pelvis will then dip or drop towards the non-bearing extremity. Now, if I continue in this attitude, I'll fall. In order to compensate for that, I'm going to shift my weight and I'm going to try to put it over the weight-bearing leg. And so, I'm going to actually swing the body towards the weight-bearing leg and try to get hypermodotic and lock back over the hip that's stabilizing or is actually supporting the weight. So, what will happen is that there will be a waddle. As the pelvis will actually drop, come back up, drop to the other side, go back and forth instead of being nice and perpendicular to where it should be to the leg. So, again, this is what it would look like if I'm going to walk. As I take this step, the pelvis will drop and shift this way. As I come through, I'll shift this way. The pelvis will drop to the opposite side. And there will be a waddle in a hypermodotic position, trying to maintain balance. So, the pelvis drops, shifting to the opposite side. The next gait pattern that we'll talk about is the Trendelenburg gait pattern. Trendelenburg gait occurs due to weakness of the glute medius muscle, which is a hip abductor or injury to the superior gluteal nerve, which innervates the gluteus medius muscle or a myopathy. Weak hip musculature causes the contralateral pelvis to drop during the stance phase of the weak hip, and this is known as an uncompensated Trendelenburg gait. The patient can then compensate by throwing their torso over the weak hip during the stance phase, and this is known as a compensated Trendelenburg gait. Treatment occurs with hip girdle strengthening, weight loss, or treatment of their pain symptoms. As you can see in the picture, you have drop of the pelvis when lifting the leg on the opposite side of the side that has a weak glute medius muscle. The next pattern of gait that we'll discuss is a neuropathic or steppage gait. This type of gait pattern can be caused by diseases of the peripheral nervous system, including radiculopathies, lumbar plexopathies, or peroneal nerve injury. The patient with foot drop in this type of gait pattern has difficulty dorsiflexing the ankle due to weakness of the anterior tibial and fibular muscles. The patient compensates for the foot drop by lifting the affected extremity higher than normal to avoid dragging the foot. Weak dorsiflexion leads to poor heel strike with the foot slapping on the ground. In this type of situation, an AFL can be helpful. When there is severe weakness, the initial contact with the ground is made by the forefoot followed by the heel region. In mild weakness, the initial contact is made with the heel followed by a rapid ankle plantar flexion causing a foot slap. During the swing phase, toes may drag or catch. Compensatory mechanisms for this type of gait pattern is a steppage gait, again, where you have excessive hip and knee flexion or a body shift to clear the foot. We'll now watch a video that discusses this type of gait pattern. Next gait is going to be that of a neuropathic gait in which the distal lobe extremity is affected. For this particular gait, the person has an inability to dorsiflex the foot, and so the foot is actually a foot drop, and the person must step high in order to clear the foot. So if I don't step high enough, I'm going to drag the toe of the shoe, and so what happens is the person steps high to be able to clear the foot as the foot drags or as the foot drops position. The next pathologic gait pattern we'll discuss is the spastic hemiplegic gait pattern. This type of gait pattern can be seen commonly in patients that experience strokes or abstract ribopalsy. The patient will stand with unilateral weakness on the affected side. Their arms may be flexed, adducted, and internally rotated. Their wrists may be flexed and their fingers may be flexed as well. The leg on the same side is then an extension with plantar flexion of the foot and toes. When walking, the patient will hold his or her arm to one side and drag his or her affected leg in a semicircle in a circumduction fashion due to weakness of distal muscles and extensor hypertonia in the lower limb. This is commonly seen, again, in stroke and CP. It also can be seen in unilateral upper motor neuron lesions. And again, we want to try to treat the underlying cause of this gait pattern if possible. The gait that I'm going to demonstrate now is a hemiplegic gait. This gait, if we were to demonstrate it, we need to be able to show the extension of the leg in internal rotation. So the leg is too long, we get circumduction with the plegic side. But very importantly as well is that the epigemony is very much involved. So there's adduction of the shoulder, flexion of the elbow, pronation of the wrist, the thumb is tucked under, and a cortical fist. So this is the position of the hemiparetic gait. The other side, the normal, epinormal, associative movements. Actually here, well, we have circumduction with the plegic side. Again, watching upper extremity posture, the cortical posture, lower extremity is actually circumducted. The next pathologic gait pattern is spastic diplegic gait. It is again commonly seen in patients with cerebral palsy. Patients have involvement of both sides with spasticity in the lower extremities worse than upper extremities. The patient will walk with an abnormally narrow base dragging both legs and scraping their hips. This gait is seen again in cerebral palsy where you have bilateral periventricular lesions. There's also extreme tightness of the hip adductors which can cause the legs to cross midline, and this is referred to as a scissoring gait pattern. Let's watch a video. The next gait is the spastic diplegic gait. In this particular gait, both lower extremities are affected, and the lower extremities are affected more than the upper extremities. So the posture, the position in this particular gait is there's flexion of the hips, flexion of the knees, and the feet or the ankles are extended and internally rotated, and there's also tight adductors, so there's adduction of the knees. So it is a swinging gait with both sides, both lower extremities, in a different pattern named a parietic gait. But this is not all. The upper extremities are also involved. Again, not as much as the hemocretic gait, but for the upper extremities, the extremity is carried in a low guard or a mid-guard position. You don't have the normal associated movements in the upper extremity. So this would be the type of posture, type of position one would see for the spastic diplegic. Moving on, we'll talk about an ataxic pathologic gait pattern. Ataxic gaits are often seen in cerebellar disease, and this gait is often described as clumsy, staggering movements with a wide base of support. While standing still, the patient's body may swagger back and forth and from side to side. This is known as titubation. Patients will not be able to walk from heel to toe or in a straight line. This may resemble the gait of acute alcohol intoxication as well. Patients with more truncal instability are more likely to have midline cerebellar disease at the vermis, causing this type of gait pattern. So that's something else to keep in mind when clinically assessing patients with ataxic gait. Let's watch a video. The last gait that I'm going to demonstrate is the ataxic gait. The ataxic gait, the patient has difficulty narrowing the station, maintaining balance. So typically, they'll have a wide stance, trying to maintain balance, and that there oftentimes will be unsteadiness in the trunk. So there may be some truncal titubation, which is an anterior-posterior type of tremor at about three hertz. And there's also a tendency to lunge or to jerk sideways for the patient that has to catch themselves. Of course, one of the ways to bring out this particular type of problem is to narrow the station, asking the patient to walk tandem. So if I then am ataxic and then try to walk tandem, then I'm going to have difficulty walking. The next gait pattern we'll talk about is career form, the career form pathologic gait pattern. This type of gait pattern is seen in patients that have basal ganglia disorders, such as Stendenham chorea or Huntington's disease. Patients will display an irregular, jerky, involuntary movement in all extremities. And walking may accentuate their baseline movement disorder. It can oftentimes resemble dancing. As opposed to the hypokinetic gait, you now have the hyperkinetic gait, which we see, we call a career form gait, or chorea. With this gait, there are not only abnormalities in the gait itself, but associated movements that can be oral facial dyskinesias, which the patient, which will be having movements on one side or the other side of the face, kind of a grimacing type of a fashion, the movements in the upper extremities, and there are fragments of semi-purposeful type of movements, or writhing type of movements. And then the legs will also start to go. And so the patient attempts to walk superimposition of the movements, but the patient doesn't actually fall because of the imbalanced stuff. Just you have these involuntary movements that are now superimposed on the gait. The final type of pathologic gait pattern we'll discuss is the Parkinsonian gait. The Parkinsonian gait is seen in patients with Parkinson's disease, and oftentimes other neurologic conditions that can affect the basal ganglia. Patients will have rigidity of joints, resulting in reduced arm swing for balance. Astute posture and flexed knees are common as well. Bradykinesia causes small steps that are shuffling in presentation. There may be occurrence of freezing or short rapid bursts of steps, which is known as festination. Furthermore, turning for these patients can be difficult as well. Oftentimes, patients will describe this gait pattern as feet sticking to the floor, as patients will have a flat foot strike where their entire foot is placed on the ground at the same time. Reduced foot lifting occurred during the swing phase, producing a smaller clearance between the toes and the ground. Patients have difficulty starting, stopping, and changing directions quickly, and there's a tendency for retropulsion or falling backwards when standing. The whole body moves rigidly, requiring many short steps and a loss of a normal arm swing. The rolling walker can be helpful in patients with this type of gait pattern. Let's watch a video. This gait is the gait that is called kinetic gait. Kinetic gait prototype is Parkinson's type of gait. It's the patient will have a posture which he can scoot over, lean forward, and then will have difficulty as far as initiating gait. When the gait is initiated, there are small steps. Oftentimes, there's a tremor associated with this. And as the gait progresses, there may be picking up a speed, what's called a finished gait. And then a turning, so having a normal turning, the patient will turn on block. So he needs to turn almost as a statue on the ground. A statue on the ground. And then, again, having difficulty starting on the arch of the body. It's important to also mention that external tactile, auditory, or visual cues that are timed with step initiation or step maintenance can help improve the gait in patients with Parkinson's. Thank you for joining me on my portion of the presentation regarding gait analysis and rehabilitation. Hi, my name is Michael Hudak. I am a PGY-1 PNR resident at Washington University in St. Louis. And my portion of this presentation today is going to focus on lower limb prosthetics and gait. And as you can see, just kind of an introduction, we're going to be focusing on obviously the hip joint, the knee, and the ankle. And we're going to be covering both trans-tibial, as you can see on the left, and transfemoral, as you can see on the right. And a key concept to keep through this is that there's both patient and prosthetic factors. What I mean by that is that there are several gait deviations that you can see with a person with a prosthetic, and that these deviations are dictated both by patient factors and prosthetic factors, which we'll get into a little bit more. So the first aspect of biomechanics of a prosthetic that we're going to talk about are the spatial-temporal changes for a prosthetic limb. Spatial-temporal meaning space and time. So we're going to be focusing on just aspects in terms of like distance, that's the spatial, and then temporal changes in various aspects of time as well. And something to note is on the prosthetic side, the stance phase is a little bit shorter in comparison to those without a prosthetic. Now, the loading response, which occurs during the stance phase, is a little bit delayed, and this has to do with limited plantar flexion of the prosthetic. And then the sound limb provides stabilization for that. And then, as you can see from the bottom chart, there's various spatial-temporal pieces of data that are listed there. And just something to note, the cadence is significantly reduced as you go from a, quote-unquote, able-bodied individual to a trans-tibial to a trans-femoral, so less steps per second. Moreover, for the velocity, you can see it also decreases as you go from an able-bodied to a trans-tibial and to a trans-femoral. And then for the step length, width, and time, there doesn't seem to be a huge difference between step width and step time. You can argue that a total time to complete a single step for trans-moral might be slightly increased. What I found interesting is the step length is a few centimeters shorter in terms of a trans-tibial, and then when you get to a trans-femoral, it is further reduced, and it's even more so reduced when you're talking about the prosthetic side. So now that we touched on a little bit just general biomechanics, and we'll get into more of the details later, I just want to kind of give a general clinical description of both trans-tibial and trans-femoral prosthetics in terms of gait. And we're going to be just focusing on, go joint by joint. So foot, knee, and hip. And we're going to start with trans-tibial. For the foot, the ankle range of motion is reduced, and this leads to a one prolonged heel strike, and a heel rise that is both earlier and greater. And then for the knee, there is a decreased flexion magnitude, or the knee is more extended than it should be, and if we're talking about a normal gait. And this occurs both the initial contact, so when you have that initial sort of shock absorption, and during the mid swing, which if you think about it, it could lead to someone swinging their leg out to provide some more clearance for their limb. And then there could be varus or valgus moments that are different, it's patient dependent, and this can be due to prosthetic or patient factors, which we'll get into later on. And then for the hip, the extension range of motion is reduced by about 50%, and this can be partially attributed to the reduced ankle range of motion concept that is key in gait is sort of a kinetic chain. So if one joint is affected, it can affect the other joints that are involved in that motion. And so that's where this reduced ankle range of motion can affect hip extension. And you can also see some hip hiking during gait as well. And then for the head, arm, and trunk, arm swing can be uneven, but it's a deviation that you can see when you're talking about transstibial gait. For the clinical description of a transmemorial gait, again, we'll be focusing on the foot, knee, hip, and then the head, arm, and trunk. For the foot, similar situation where you have an ankle range of motion that is reduced, lean to the same sort of clinical description you see for transstibial. And then for the knee, now we no longer have our biological knee. We have a prosthetic one. So for the free knee, is what we're going to call it, that's going to be the extremity that does not have the prosthetic. Extension appears to be prolonged to prevent instability on the prosthetic side front buckling. And then for the fixed knee, there's a lack of knee flexion, and this can lead to reduced prosthetic clearance on that side, which can lead to things like hip hiking, as you can see. For the hip portion, there is hip hiking, and this is also due to a secondary lack of prosthetic dorsiflexion. And for the hip, you can also have an AB-ducted gait. For the head, arm, and trunk, you can have bending of the trunk, but you can also have an increased lumbar lordosis, which could lead to back pain in these individuals, and in addition to the uneven arm swing that we saw in the transstibial portion as well. Now we're going to talk about the kinematics of gait prosthetic, and kinematics focuses on joint angles. For the hip and pelvis, there's an overall reduction in hip range of motion. The prosthetic leg extension range of motion is overall decreased, and this is secondary to a lack of ankle range of motion, referencing this kinetic chain that we had discussed earlier. And then for the pelvis range of motion, different from hip range of motion, in the frontal plane, there is an overall increase for the lower limb prosthetic, and this is sort of known as hip hiking. And then for the pelvis range of motion in the sagittal plane, specifically for a transfemoral prosthetic, there is an increase, eight degrees versus four degrees, which appears to be a fairly significant difference between the two, and people have thought of this as a possible cause of lower back pain. For the knee, we're going to mostly talk about flexion for the loading phase or the shock-absorbing phase, and for the able-bodied individual, those without a prosthetic, and the sound side of a person with a prosthetic, the knee flexion appears to be, during the loading phase, 15 to 18 degrees, but as you see for a transtibial, it's reduced between nine and 12, and a transfemoral, obviously, they're essentially nonexistent, depends on the prosthetic, but there is a difference between the flexion in that shock-absorbing phase, especially as you go from a transtibial to transfemoral. And then for the foot, specifically referencing plantar flexion, for an able-bodied individual, which is the AB, it's about 10 to 15 degrees, and then for a lower-limb prosthetic, it's between 4.5 and 8.3, and this depends on the prosthetic foot that you use. And for dorsiflexion, particularly during the mid-late stance, an able-bodied individual is 20 to 23 degrees, versus a lower-limb prosthetic is going to be a 12.5, approximately, but again, this is prosthetic-dependent. Now we're going to talk about kinetics of prosthetic gait, which focuses on forces of joints. And for the hip, it appears to be double in the satchel plane for those with prosthetic versus those without, and this is actually thought to generate power, especially during the early stance. And for the knee, the flexion moment in transtibials is reduced compared to able-bodied individuals, and in transfemoral, it's even smaller, which sort of gives some insight as to why the hip needs to sort of compensate for the lack of flexion moment in the knee in a prosthetic individual. And then also for the ankle, the plantar flexion moment, it is longer in prosthetic individuals, but the time to achieve flat foot is increased individual, and the dorsiflexion moment is reduced, again, sort of giving reason as to why the hip might need to generate more power during the gait cycle, especially during the early stance phase. The second part of kinetics is going to be power instead of moment, and for the hip, there is an overall greater amplitude and duration of power on both sides for a person using a prosthetic versus an able-bodied person. On the prosthetic side, there is quote-unquote pull-off via the concentric action of the hip flexors, and this is increased for a person using a prosthetic. And on the sound side, the hip extensors, there's an increased power generation as well in the early stance slash prosthetic push-off. In the knee, there's reduced absorption of power on the prosthetic side for a knee, and this is sort of compensated on the prosthetic limb. The hip is used for shock absorption, power absorption and generation, and in the sound limb, the knee is overloaded. And for the foot, for the push-off, the prosthetic produces about 20% of the work compared to the push-off for an able-bodied individual, and then so for the intact limb, one that's not using a prosthetic, there's compensation. The ankle produces more work during push-off, and as I said before, the hip extensor work, the concentric power is increased, and then the prosthetic limb compensation, there's that concentric hip pull-off. Another aspect of biomechanics is the EMG, which measures muscle activity, and one of the main muscles in the quadriceps is the vastus lateralis, which is, for a person using a prosthetic, they rely more on it for weight acceptance than they do their knee extensors. As you can see, in trans-tibial amputees, it is greater than able-bodied individuals by about 25%, and it lasts longer as well throughout their gait cycle. For the gluteus maximus and hamstrings, these are both also increased on EMG and thought to be a possible source of power due to lack of ankle push-off, which we have mentioned previously. As for trunk musculature, specifically the thoracic and lumbar erector spinae, which are abbreviated TES and LES, they appear to adopt proximal muscle strategies to help advance them, so they rely more on their trunk musculature to assist in their gait than somebody who does not wear a prosthesis, and also the range of motion for the trunk is increased as well. There's also altered trunk muscle activation. For the intact stance, the TES and LES are not active on initial contact and remain active longer through the early stance, and this corresponds to an increased lateral flexion toward the affected side, meaning the prosthesis, and during the intact, so the non-prosthetic side, swing phase, there appears to be a secondary activation in those wearing prostheses, and this moves the center mass to the intact side to prep for the intact heel strike and the gait. Energetics is another aspect of biomechanics that we're going to cover, and the general rule is that the more proximal the amputation, so as you go from a trans-tibial even to a further up trans-tibial to a trans-femoral, and as you work your way up, there is a higher metabolic cost the more proximal the amputation is, and it has been noted that compensation for these higher metabolic costs is by reducing their CWS, which is comfortable walking speed. Moreover, the relative aerobic load, which they measured as percent of their VO2 peak, which reflects VO2 max, was higher in a lower limb amputee, and interestingly enough, VO2 max is used as a possible indicator for prosthetic use potential. In regard to these energetics, one study that we found used oxygen consumption and heart rate to sort of define their definition of energetics, and oxygen consumption is here on the left while heart rate is here on the right, and while I believe there was only a real significant difference on the oxygen consumption between the green, the trans-femoral versus the trans-tibial and control, I think these graphs do show a nice sort of trend towards difference that is fairly convincing. It would be interesting to see how further studies see if there's any sort of difference between them, but for oxygen consumption as you can see for the control, which is the blue, it is the lowest and as you increase walking speed, oxygen consumption increases, but it's not as high as those with trans-tibial and then trans-femoral is even higher. And this is sort of also reflected on the heart rate side where you have the blue, there's the control, and then the trans-tibial is again higher as you compare walking speeds and as you increase walking speed, and then for the transfemoral it is even higher. Another measure of energetics is PCI or physiological cost index. What this does is it takes the mean heart rate while walking, subtracts the mean heart rate while resting, giving a difference in heart rate, and you divide that by the comfortable walking speed, giving you this number which they defined as PCI, physiological cost index. And what they did is they graphed PCI versus stump length. So as you see on the left chart, as stump length increases, you get a decline in physiological cost index, which reflects what I had mentioned prior where the energetics is thought to, the energy expenditure decreases as the stump length increases, or it is more work the shorter the stump length is. And then also for, they took the comfortable walking speed, which is using the graph on the left, I mean the right, my apologies, and they charted it against the stump length. As you see, as the stump length increases, the trend is the individual has a higher comfortable walking speed than those with a shorter stump length. So we talked a lot about the different biomechanics that you can see in those with trans-tibial and trans-femoral amputations, and the overall, there's a lot of nuances, and the overall big picture idea you can take away from this is that for these differences in gait, these gait deviations, there are both patient and prosthetic device factors, and what a patient is experiencing really depends on those two things, and as a, as you're assessing gait, it's good to figure out, you know, whether this is a patient factor or a prosthetic factor that's causing this gait deviation and address those accordingly. So keeping in mind that there are both patient and prosthetic factors that contribute to gait deviations, we can actually break down the different aspects of gait and start to note the different prosthetic and patient factors that might contribute to those deviations, and we have trans-tibial denoted in red for those specific to trans-tibial, and then green for trans-femoral, or we'll have TT or TF to denote whether it's specific to that type of prosthetic. Otherwise, it's hard to be sure. For the step length, it can be short, and for prosthetic factors, this can be due to knee friction that's inadequate or socket fit, patient factors, pain, feeling of instability, possible muscle weakness, the base of support can be narrow or broad, and this has to do with foot, in-set or out-set, and for patient factors, this can be from the hip, AD, AB or a feeling of instability, like that from neuropathy, and then for foot rotation, it can be external, and this is just from the foot actually, the prosthetic foot being externally rotated, or the heel wedge can be hard and the plantar flexion bump can be stiff or the socket can be loose, and then for patient factors, hip strength can be inadequate and weight to compress heel is inadequate. Other deviations include that of the knee, where you can have excessive flexion, and this can be from a foot that is dorsiflexed, a heel that is high, for transtibial, you can have a socket that is flexed or has an anterior tilt, for transfemoral, a socket that is posterior, and a knee axis anterior to the TK line for the transfemoral, and then for patient factors, you can have contracture, spasticity, and increased length. There can also be hyperextension, and that's from essentially the opposite, a foot that is plantar flexed, and for transtibial, a socket that's extended or a posterior tilt, and for transfemoral, an anterior flexed socket, and then patient factors, quadriceps spasticity, backstroke weakness, etc., and for trunk, you can actually have an anterior lean, and this is from a knee axis that is anterior to the TKA line, a socket that has inadequate flexion, and patient factors, again, quadricep weakness, flexion contracture, spasticity, etc. Now, for coronal plane deviations, in regard to foot weight placement, it can be medial or lateral, and this has to do whether the foot is inverted, everted, patient factors include genuvalgum versus genuvarum, knee, you can have a varus or valgus thrust, again, this is foot inset, outset, socket that is AD or AB ducted, and trunk lean in regard to a prosthetic limb or intact limb, a length that is reduced, socket that is AD ducted, and patient factors include AB ductal weakness, coccybara, AD duction, contracture, hip pain, and such. The gait deviations we just talked about are in regard to the stance phase, and now we're going to talk about the pre-swing and swing phase for gait deviations. This will be shorter than the stance phase, but these are all going to be in the sagittal plane, and some of the deviations you can have are in regard to the push-off, which could be insufficient or early, and prosthetic factors typically focus on the foot, the foot being posterior or dorsiflexed, and then patient factors are voluntary limitation, and then the heel rise delayed or in the case of transfemoral rapid, and for the heel rise focusing on again those foot factors, but also for the transfemoral the knee can be involved as well, particularly having inadequate friction, and the patient factors again being voluntary. For the impact, it can be high, and for the transfemoral this typically involves the knee, and then for patient factors, voluntary force to avoid falling, and for whip circumduction bolting, I just recommend looking up videos to get an idea of what those look like, and for the whip on a transfemoral patient, it can be medial or lateral and just has to do with whether the knee is externally or internally rotated, but it can also be due to poor socket fitting. For the circumduction and bolting, this has to do with the length of the prosthetic, the foot, suspension, knee, basically all the way throughout. There's multiple prosthetic components that can contribute to these deviations, and then in patient factors, you can have contractures, particularly for the abductors of the hip. Now we went through a lot of nuances of gait and gait deviations in those who use prosthetics. There are also functional measurements that one can use to assess gait in those using a prosthetic, and we just listed some here, the AMP Pro being a common one, the basic amputee mobility score, timed up and go test, two and six minute walk test, there are several others, these are just a few that we decided to list. Basic rehabilitation interventions you can use to fix abnormal gait or gait deviations in those using a prosthetic really starts with prescribing the appropriate prosthetic, using gait training to help a patient become more comfortable with their prosthetic, and then identify any gait deviations and the potential causes, whether patient or prosthetic, during training so that they can maximize their use of their prosthetic, and you can address patient factors by training as best as possible and prosthetic factors by modifying the prosthetic. And here are the references, and so this is just an overview of the patient and prosthetic factors that go into gait deviation and I hope you all enjoyed. Hi, I'm Jared Levin, one of the Pediatric Rehabilitation Medicine Physicians at Washington University St. Louis Children's Hospital. Hi, I'm Cherie Smith, I'm one of our other Pediatric Rehab Medicine Physicians, and today we're excited to talk with you about cerebral palsy and gait. A little overview of what we're going to discuss today includes clinical description, anatomic correlation and patterns of cerebral palsy, domains of measurement, functional gait measures, and rehabilitation strategies in treating our patients. To start off with a definition of cerebral palsy, it can be described as a static, non-progressive brain injury that can occur prenatally, perinatally, or within the first few years of life, resulting in a neuromotor control deficit affecting movement and posture. Some of the movement patterns we may see in cerebral palsy, asbestos being the most common that we tend to see in the U.S., as well as dyskinetic patterns such as apoptosis, chorea, dystonia, along with hypotonic CP and ataxic CP. We can also see mixed forms, one of those commonly patterns we see asbestos and dystonia coexisting together and not always clear distinction between the two. Next, looking at the anatomic patterns that we see in our cerebral palsy patients. First, monoplegia affecting one lower extremity typically, or hemiplegia affecting an upper and lower extremity, similarly to what you may see in your adult stroke patients. We also have diplegia, where it affects both lower extremities, or quadriplegia affecting all four extremities. I also have starred here functionally triplegic. This can be a pattern that can have a combination of diplegic and hemiplegic or quadriplegic, where one of their upper extremities they're able to use without any functional limitations. A newer classification system also used for describing anatomic patterns is unilateral and bilateral, with the unilateral referring to the monoplegic and hemiplegic, and bilateral referring to our diplegic and quadriplegic patterns. Next, looking at the gross motor function classification system, or GMSCS levels. These range from levels one through five, with level one being our independent ambulators that don't need any assistance with their mobility, and level five being those that are dependent on their caregivers for their mobility. Levels two through four vary in the level of assistance they need for ambulation, such as utilizing a railing, forearm crutches, manual wheelchair, or powered mobility. To tie the previous three slides together, some examples of pediatric patients with cerebral palsy you may hear them refer to is spastic quadriplegic cerebral palsy, GMSCS level five. This is a patient that has spasticity affecting all four extremities and are dependent on their caregivers for their mobility. Another example would be spastic diplegic cerebral palsy, GMSCS level two. An example of this would be our toe walkers. Now I'm going to hand it over to Dr. Levin to talk about our gait. So along with classified cerebral palsy, as we've previously discussed, we also have a number of gait patterns that we commonly see in patients with cerebral palsy, which again is often dependent on the limbs involved, the type of movement abnormalities they have, the severity, and the degree of wear and tear. So we have a number of different types of gait patterns. Some of these common patterns include a hemiplegic gait pattern with one leg and arm affected, a scissoring gait pattern in which due to increased adductor tone with every step each leg crosses in front of the other, an aquinas or spastic toe walking gait pattern, a jumper or crouch gait, and a stiff knee gait. In looking at patients with a hemiplegic gait pattern, there are multiple classifications systems that can be used to further break down the gait pattern. A commonly used one is the rhodoembryon classification system. This classification system essentially looks at the gait based on the number of limb segments involved and how severely they're involved, with a type 1 being essentially a drop foot in which there's increased plantar flexion during the swing phase either due to ankle weakness or increased tone and contraction. In contrast, a type 4 hemiplegic gait pattern is one in which there are multiple joints affected with deviations in multiple planes of motion. It is important to note that in general with a hemiplegic gait pattern we're more likely to see knee genu valvum as well as ankle varus deformities, an understanding that may help us target specific muscles to treat when we're looking at a patient with CP. As an example of a patient with a hemiplegic gait pattern, we have some kinematic data taken from some video analysis here on the left. Understanding that not everyone is familiar with using video analysis data to analyze a patient's gait, we'll quickly go through how to look at this information. On this graph we have three columns, each one indicating a different plane of movement indicating a different plane of movement with multiple rows looking at each limb segment or joint as it moves through in its single gait cycle going on the x-axis on each graph from stance to swing phase. We have in the grayed out area normal patient norms for each limb segment going through the cycle and to compare to that we have the right and left limb indicated by the green and red lines respectively. In this patient, again with a right hemiplegic gait pattern, we see deviation in increased ankle plantar flexion during the swing phase as indicated by the bright yellow circle in the bottom left graph. As you can see the green line is well below where the gray line and the red line are running. Also on this graph we can see there's increased knee hyperextension in the stance phase. This is indicated by the orange circle right above and over to the right we can see that there's increased external rotation likely due to tibial torsion. Within the diplegic gait patterns there are multiple gaits that we've previously talked about along with the Aquinas gait pattern which is typified by bilateral ankle plantar flexion, oftentimes with knee hyperextension. We have both the jumper and crouch gait which are typified by hip and knee flexion. What differentiates these two gait patterns is that in a crouch gait we more commonly see increased ankle dorsiflexion whereas in a jumper gait we either see continued ankle plantar flexion or increased ankle plantar flexion during toe-off as if the patient is pushing off to jump. Here we have some kinematic video analysis footage taken from a patient with an Aquinas diplegic gait pattern. In this we can see that the patient has increased plantar flexion throughout the gait cycle as indicated by the orange circle. We also see interestingly that they have increased hip flexion contractors indicated by the yellow circles above. However this patient cannot be typified as a jumper's gait. However this patient cannot be typified as a jumper's gait because they do not have the knee flexion that we would expect which is indicated by the purple circle. So as physiatrists it is our goal to help patients improve their gait. We often have to do this first by understanding what is happening during the patient's walking. The first tool we have is our basic physical exam. We can look at a patient's range of motion to assess for any contractures they may have, looking at any tone abnormalities by assessing their spasticity, dystonia, etc., and also looking for any weakness with a strength exam. This can then be followed by watching a patient walk with a visual gait analysis and this can be supplemented with both video gait analysis and an instrumental gait analysis with tools such as accelerometers or force plates. These extra tools can be used to provide more discrete information to supplement what we can see. Oftentimes it's also very useful to have functional gait measures to give us information about how a patient is progressing over time or how their gait has changed after intervention. Along with the GMFCS which is probably one of the least sensitive tools we have, we have the gross motor function measure which is a tool we'll talk about on the next slide. We have other tools such as the six minute walk test which tells us how far a patient can walk over six minutes and again video gait footage can give us discrete information about what is happening during the gait cycle. The gross motor function measure is a tool that indicates how independently a patient is moving in multiple areas of mobility such as in the bed, through transfers, sitting, crawling, standing, walking, and running. There are multiple versions of the GMFM, each one tailored to different patient populations and what equipment they commonly use. And because the GMFM looks at multiple areas of mobility and function, it oftentimes is more sensitive than the GMFCS and therefore more useful in research purposes. So to wrap up, we want to finish with the rehabilitation strategies in treating these patients. And as in all of rehab, our treatment regimens should be individualized and tailored to each patient. As Dr. Levin alluded to in the previous slides, various patients will have unique levels of limb involvement, tone and movement disorders and weakness, as well as range of motion limitations that are affecting their gait. We're also talking about pediatrics that develop and grow as they age and as they do so then the goals and treatment strategies utilized will need to be varied to accommodate their growing and improved development. We should also look at targeting what are the patient and family goals and how best we can achieve those in our treatment strategies. So looking at this as kind of a tiered approach, starting with our physical and occupational therapy. Also with pediatric patients, often we like to try to incorporate play as much as we can into their therapy. So some examples of tools we have are pool therapy, which can be very fun, but it can also have that benefit of the weightless activity to work on gait mechanics. We also have hippotherapy, which can work on core and pelvic girdle muscle strengthening as well as balance training. And next we have dance and martial arts, particularly if these are areas of interest for the child to improve their therapy sessions. And these types of activities can help improve isolating certain muscle movements when they're practicing their dance or their martial arts. Next, looking at whether or not they need bracing, various equipment and mobility devices to assist them in their gait training, as well as their functional gait. Next tier we like to look at is whether or not they need interventions for their tone. First line typically being looking at oral medications or targeted therapy with Botox or chemical alcohol injections. We also have surgical procedures such as selective dorsal rhizotomy, intrathecal baclofen pump, deep brain stimulators. We can also integrate orthopedic surgical correction surgery for joint deformities and muscle pain. Lastly, looking at that holistic approach we like to take in treating our patients, also want to look at secondary factors that can greatly impact their gait. Some examples of this being gait, pain, epilepsy, or respiratory function, and making sure that we're optimizing these factors as well. For our references, thank you very much for having us.

cerebral palsy

gait patterns

spastic pattern

dyskinetic pattern

ataxic pattern

monoplegia

hemiplegia

diplegia

quadriplegia

GMFCS

hemiplegic gait

scissoring gait

equinus