April 2021

Perspective 360: Of Gait Analyses and Elephants

While researching the history of gait analysis to prepare for this issue, the parable of the blind men and the elephant kept coming to mind. The ancient story is of a group of blind men who have never seen an elephant. On encountering a live elephant, they each touch a different part of the large mammal and come away thinking they know what it is. They then describe the elephant based on their own experience and find all their descriptions differ. The moral of the story points to the tendency of humans to claim they know things based solely on their own experience, not recognizing that others may have completely different experiences. Could this be the case with gait analysis and the various subspecialties who treat the lower extremity? Is gait analysis being used to its fullest extent?

With this issue, LER is pleased to open an ongoing partnership with the Gait and Balance Academy to provide an in-depth look at all things gait analysis. The introduction to this partnership, “How Do We Use Gait Analysis to Measure Walking Consistency,” is written by Arnaud Gouelle, PhD, and Patrick Roscher, MS, from ProtoKinetics; the article begins on page 27. We look forward to your feedback.

But first, to broaden the narrative, a sampling of perspectives on how gait analysis is used in some specific circumstances.

Janice T. Radak, Editor 

…In Orthotics and Prosthetics

Normal human locomotion requires a complex interaction of anatomical segments, moving synchronously in relation to each other and the body’s center of mass and incorporating dynamic propulsion from point “A” to point “B.” Because of its’ complexity, bipedal locomotion, aka gait, has been extensively researched and utilized in the diagnosis and treatment of complex orthopedic conditions. Over the past half century, human gait has been dissected and studied, initially using still images-then videography until the evolution of computerized motion analysis. Gait labs have proliferated as the understanding of the kinetics/kinematics of walking have been illuminated by sophisticated computer software programs, 3D videography, and force plate data. Numerous institutions have access to state-of-the-art gait labs for pre-op diagnosis and post-op quantification of outcomes. However, despite the growing subscription to the value of computerized motion analysis, these resources are few and far between in relation to the practicing orthotist/prosthetist. So, what is the true impact of gait analysis on the average O&P professional who has minimal affiliation with a major medical/academic institution? The answer may be much more linear than one thinks.

Gait analysis does not necessarily have to involve a fully outfitted motion lab. It can be as pedestrian as observing/recording a 10-meter walk test in a specific orthotic design. Or it can be the use of one of the several user friendly/affordable gait assessment tools on the market today (GaitRite, Motion Monitor, etc.) or recently available phone apps that record sensitive gait data directly on your smart phone. The most critical implication that the gait analysis technology has had on orthotics/prosthetics today is the heightened awareness of the value of quantitative and qualitative data on evidence-based practice. The accumulation and summative reporting of gait data as a result of specific O&P interventions has led to a greater number of scientific publications than ever before. Today’s practitioner must be acutely cognizant of the impact of their interventions on key aspects of their patient’s functional performance with functional gait often the ultimate goal. Even if the “analysis” is purely observational in nature, the fundamental understanding of normal human locomotion, identification of pathologic deviations and the correlation between what we do and how it effects complex joint kinetics/kinematics/energy consumption and balance demonstrates the profound impact that the study of human motion has had on orthotics/prosthetics. Everyday we make clinical decisions based on our gait analysis. Component selection, design features, alignment, and material selection are all contributing factors to the optimal outcomes we strive for. The relationship is inextricable and profound.

Robert S. Lin, MEd,CPO,FAAOP is Managing Partner at Biometrics INC in Hartford, CT. In practice for over 40 years, he has lectured extensively on gait, biomechanics, and pediatric orthotics. Lin also serves on the LER Editorial Advisory Board.

…In Running

Weekly I am posed the question from patients, physicians, therapists, and coaches as to whether I perform “gait analysis.” The simple answer is YES, as I am keenly interested in the unique movement patterns of all of my patients. As a sports medicine clinician, I need to understand an athlete’s asymmetries and weaknesses that may lead to pathologies. This is particularly true for runners.

The part that becomes confusing is what the asker’s expectations are of what this term means and how this process is carried out. The common practice of having a runner hop on a treadmill and watching them from behind is not gait analysis and should never be touted as such. Understanding the runner’s movement patterns through an organized approach is the only way to help them achieve metabolic efficiency and decrease the risk of injury.

By definition, gait analysis is the systematic study of human motion, using the eye and brain of the observer. This may be augmented by instrumentation that may help measure the movements and mechanics of the body.

The process begins with GREAT communication. A thorough history will help the physician understand what the athlete’s goals are. Once the goals are established, the clinician must listen to the patient’s story to understand where they have come from and why they are seeking your expertise.

To truly understand a runner’s gait, a simple dynamic assessment is critical. Asking the runner to perform simple tasks of single leg balance and squats are key to uncovering areas of weakness and asymmetries. Typically, these inequalities are quite glaring and the source is usually higher up the kinetic chain from where the pathology is felt. The great aspect of this is that the runner can actually feel and see their deficit if we are utilizing a mirror or video recording.

While not always realistic, the best way to analyze a runner’s gait is to observe them when they do not know they are being watched. Sometimes even catching their movement patterns when walking into the clinic can be quite informative.

Finally, it is imperative to understand how the runner uses stability, power, and strength when running to analyze their form. The best way to do this is to watch them run from a multitude of perspectives outside as opposed to on a treadmill. Motorized treadmill running takes quite a bit of acclimation and may not truly assess the individual’s form.

The goal of gait analysis is to tie in all of the above information in order to document and quantify objectively normal gait, functional deficits, and put forth a therapeutic plan.

Robert M. Conenello, DPM, is a is the founder and sole proprietor of Orangetown Podiatry, a New York metropolitan-based practice, whose emphasis is on prevention and rehabilitation of lower extremity pathologies. He is the Clinical Director of the Special Olympics New Jersey Healthy Athletes division and the Past President of the American Academy of Podiatric Sports Medicine. Conenello also serves on the LER Editorial Advisory Board.

…In Falls Prevention

Walking is a complex motor task generally performed automatically by healthy adults. Yet, by the older adult, walking is often no longer performed automatically. Older adults require more attention for motor control while walking than younger adults. Falls, often with serious consequences, can be the result. Gait impairments are one of the biggest risk factors for falls. Several studies have identified changes in certain gait parameters as independent predictors of fall risk. Such gait changes are often too discrete to be detected by visual observation alone. For proper analysis of gait disorders in the older adult, research shows the use of a pressure mapping system allows a clinician to obtain quantitative data necessary for accurate evaluation of the individual, which leads to appropriate clinical pathways. Multiple companies offer pressure mapping technology for gait analysis. Utilizing such technology for dynamic postural control in the older adult, a key area should be examined, the sensory system. Sensory systems in older adults have been implicated in their reduced ability to adapt to changes in the environment and maintain balance; the visual system is particularly important in maintaining postural stability. There are distinct changes in gait associated with the visual system, such as slower gait and increased gait variability. Exposure to visual perturbations and manipulations emphasizes these changes in gait. Increased gait variability, specifically with mediolateral perturbations, poses a particular challenge for older adults, as it has been linked to falls. Thus, treatment to improve balance along with gait in the older adult is imperative to overall positive outcomes and continued independent living.

Philip Stotter, veteran clinical exercise physiologist turned inventor/business developer, is the Visionary and Founder  behind The Stotter Clinic, Moflex, AA360, and others. These days, Philip focuses on ground mechanics and how to use technology to augment the test/treat or test/train intervention process. His most recent venture is as Director of Sports Science for V1 Sports. Based in Cleveland, OH, he is the newest member of the LER Editorial Advisory Board.  

…In Footwear

Gait analysis and the influence of various types of footwear is wide and varied, each of which integrate components of kinematics, kinetics, electromyography and efficiency measures. In more recent times, gait analysis has been supported by patient-/participant-centered outcomes that feature aspects of comfort, perception of footwear and pain, enabling a comprehensive overview from a multi-disciplinary and patient-centered educational perspective. On a daily basis, footwear for many of us is an attire not just for fashion but for its rudimentary properties that include protection, stability, cushioning, fitting, and flexibility. When footwear is worn, it provides the interface between the foot and the supporting surface and whilst this can offer functional support and protection to the foot, it can reduce tactile feedback compromising postural stability and balance. Such features are made worse, with high-heeled footwear and thicker outer soles, increasing the risk of falls, particularly in older individuals who are advised to wear slip resistant soles and low heels.

Running footwear and analysis is perhaps one of the leading areas of research with studies exploring the impact of cushioned and supportive to minimal footwear design on the impact of running economy, asymmetry, spatial and temporal parameters, footstrike, impact forces, limb alignment and muscle function. Compared to conventional (cushioned/supportive) running footwear, minimalist footwear is characterized as having a lower profile and heel-to-toe drop, increased flexibility of the sole and a smaller mass. These features are considered to provide minimal interference to the natural motion of the foot with studies reporting a forefoot or midfoot strike and reduction of impact forces, which for some individuals minimizes the risk of injury.

The notion of minimal footwear has translated to everyday footwear – but has received little attention in the literature, especially when stability and the functional effects are considered for older adults and the potential risk of related falls. In a recent study, Cudejko et al employed a repeated-measures design of 13 types of footwear conditions in 22 adults (mean age 55.4 years, SD 7.8) that ranged from barefoot, conventional, to minimal footwear. These authors found that postural and dynamic stability (one of which included the center of pressure) improved with minimal footwear, even when compared to barefoot, features of which support similar findings of Peterson et al. Cudejko et al also noted that the participant’s perception on choice of design of footwear was one that disfavored a higher ankle collar and split toe, each of which were considered unfashionable. Whilst further research is needed, the future design of minimal footwear may be able to decrease the risk of poor stability and reduce the risk in falls in older adults, as well as enhancing patient compliance.

Sarah Curran, PhD, is Professor of Podiatric Medicine and Rehabilitation at the School of Sport and Health Sciences, Cardiff Metropolitan University in the United Kingdom. She is a long-standing member of the LER Editorial Advisory Board.

…In the Assessment of Neuropathy

Peripheral Neuropathy (PN) is a prevalent condition among patients with diabetes. The utilization of gait analysis is a vital tool in assessing the physiological manifestations of PN. For example, Suda et al utilized the measurement of toe clearance to assess how PN predisposes patients to falling and tripping. Huang et al utilized the measurement of toe elevation, stride time, and stance time to assess how PN affects a patient’s gait while study participants stepped over obstacles. Dingwell et al utilized kinematic data to characterize walking speeds and gait variability in PN patients. These studies have aided in our understanding of PN and its consequences on gait mechanics.

Currently, there are two overarching theories on these effects. One theory is that patients with PN move more conservatively to maintain their balance and gait, resulting in a person walking “stiffer” and more “robotic.” In this scenario, there are compensatory mechanics that stabilize gait. The opposing theory is that patients have more erratic or variable gait due to the lack of proprioceptive feedback. Utilizing gait analysis techniques such as center of pressure measurements from sequential steps in patients with PN can characterize gait patterns to assess which theoretical construct is present in these patient groups. Insights gained from sophisticated algorithms (such as wavelet analyses, Lyapunov exponents, or maximum Floquet multipliers) coupled with new wearable sensors, will almost certainly increase our understanding of the systemic effects of neuropathy and potentially provide researchers and clinicians with new tools to treat gait abnormalities caused by diabetes.

Jessi K. Martin is a Master’s degree student at Cleveland State University in biomedical engineering. Brian L. Davis, PhD, is Associate Dean of the College of Engineering and Professor of Biomedical Engineering at Cleveland State University, Cleveland, OH, where he focuses on the development of rehabilitation technology and instrumentation for assessing a patient’s risk for diabetic foot ulceration. 

…In Return-to-Play Decisions

Gait analysis is central to the return-to-play decision-making process for nearly all athletes recovering from lower extremity injuries. Because athletes in different sports have varying functional demands among running, jumping (and landing), and agility, a clinician’s gait analysis should be tailored to assess the tasks specific to an individual athlete’s demands. Gait analyses should include both subjective and objective assessments of an athlete’s gait. Observation of athletes can be performed in controlled situations such as treadmill running as well as in sport-specific contexts (eg, on the practice field or court). The athlete should also be asked about their perception of recovery and confidence, or lack thereof, when performing challenging maneuvers. Objective measurement approaches can range from low tech (eg, smartphone apps involving basic video analysis) to high tech (eg, 3-D motion analysis and instrumented treadmills). The continuing evolution of wearable biomechanical sensors provides another option for objectively assessing athlete’s gait in sport-specific contexts.

Key parameters during gait evaluation should include whether the athlete’s movement patterns involve any guarding or compensations that may indicate an attempt to protect the recovering injury. While perfect limb-to-limb symmetry in objective gait measures is rarely realistic, differences of greater than 10% to 15% between injured and uninjured limbs should be concerning. I subscribe to the mantra of “you can’t manage it if you don’t measure it”. Thus, I advocate for documentation of both subjective and objective gait analyses so key outcome measures can be tracked as an athlete moves through a return-to-play progression. I also think that a single gait analysis should not be the only benchmark on which a return-to-play decision is made. Instead, the determination of an athlete’s readiness to return-to-play should be based on a series of decisions that are made throughout an athlete’s recovery from lower extremity injury. Gait analysis, in multiple forms, should be part of those decisions throughout the recovery and rehabilitation process.

Jay Hertel, PhD, ATC, is Chair of the Department of Kinesiology and Joe Gieck Professor in Sports Medicine at the University of Virginia in Charlottesville, VA. Hertel also serves as Editor-in-Chief of the Journal of Athletic Training.

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.